前言
iOS开发过程中，各种小问题，小技巧，代码片段， 在这里收集，写下，方便查阅，有时间会将其分类，并添加导航和标签。
PS:查找东西，现在只能用com+f,搜索关键字查找。。。
本文应该不在更新，或者说不在blog中更新了，有点麻烦，我会在Github中继续更新，链接地址
返回输入键盘
<UITextFieldDelegate>
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
return YES;
}
CGRect
CGRectFromString(<#NSString *string#>)//有字符串恢复出矩形
CGRectInset(<#CGRect rect#>, <#CGFloat dx#>, <#CGFloat dy#>)//创建较小或者较大的矩形
CGRectIntersectsRect(<#CGRect rect1#>, <#CGRect rect2#>)//判断两巨星是否交叉，是否重叠
CGRectZero//高度和宽度为零的，位于（0，0）的矩形常量
隐藏状态栏
[UIApplication sharedApplication] setStatusBarHidden:<#(BOOL)#> withAnimation:<#(UIStatusBarAnimation)#>//隐藏状态栏
自动适应父视图大小
self.view.autoresizesSubviews = YES;
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
UITableView的一些方法
这里我自己做了个测试，缩进级别设置为行号，row越大，缩进越多
<UITableViewDelegate>
- (NSInteger)tableView:(UITableView *)tableView indentationLevelForRowAtIndexPath:(NSIndexPath *)indexPath {
NSInteger row = indexPath.row;
return row;
}
把plist文件中的数据赋给数组
NSString *path = [[NSBundle mainBundle] pathForResource:@"States" ofType:@"plist"];
NSArray *array = [NSArray arrayWithContentsOfFile:path];
获取触摸的点
- (CGPoint)locationInView:(UIView *)view;
- (CGPoint)previousLocationInView:(UIView *)view;
获取触摸的属性
@property(nonatomic,readonly) NSTimeInterval timestamp;
@property(nonatomic,readonly) UITouchPhase phase;
@property(nonatomic,readonly) NSUInteger tapCount;
从plist中获取数据赋给字典
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"book" ofType:@"plist"];
NSDictionary *dictionary = [NSDictionary dictionaryWithContentsOfFile:plistPath];
NSUserDefaults注意事项
设置完了以后如果存储的东西比较重要的话，一定要同步一下
[[NSUserDefaults standardUserDefaults] synchronize];
获取Documents目录
NSString *documentsDirectory = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];
获取tmp目录
NSString *tmpPath = NSTemporaryDirectory();
利用Safari打开一个链接
NSURL *url = [NSURL URLWithString:@"http://baidu.com"];
[[UIApplication sharedApplication] openURL:url];
利用UIWebView显示pdf文件，网页等等
<UIWebViewDelegate>
UIWebView *webView = [[UIWebView alloc]initWithFrame:self.view.bounds];
webView.delegate = self;
webView.scalesPageToFit = YES;
webView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[webView setAllowsInlineMediaPlayback:YES];
[self.view addSubview:webView];
NSString *pdfPath = [[NSBundle mainBundle] pathForResource:@"book" ofType:@"pdf"];
NSURL *url = [NSURL fileURLWithPath:pdfPath];
NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:(NSURLRequestUseProtocolCachePolicy) timeoutInterval:5];
[webView loadRequest:request];
UIWebView和html的简单交互
myWebView = [[UIWebView alloc]initWithFrame:self.view.bounds];
[myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.baidu.com"]]];
NSError *error;
NSString *errorString = [NSString stringWithFormat:@"<html><center><font size=+5 color='red'>AnError Occurred;<br>%@</font></center></html>",error];
[myWebView loadHTMLString:errorString baseURL:nil];
//页面跳转了以后，停止载入
-(void)viewWillDisappear:(BOOL)animated {
if (myWebView.isLoading) {
[myWebView stopLoading];
}
myWebView.delegate = nil;
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
汉字转码
NSString *oriString = @"\\u67aa\\u738b";
NSString *escapedString = [oriString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
处理键盘通知
先注册通知，然后实现具体当键盘弹出来要做什么，键盘收起来要做什么
- (void)registerForKeyboardNotifications {
keyboardShown = NO;//标记当前键盘是没有显示的
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWasShown:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWasHidden:) name:UIKeyboardDidHideNotification object:nil];
}
//键盘显示要做什么
- (void)keyboardWasShown:(NSNotification *)notification {
if (keyboardShown) {
return;
}
NSDictionary *info = [notification userInfo];
NSValue *aValue = [info objectForKey:UIKeyboardFrameBeginUserInfoKey];
CGSize keyboardSize = [aValue CGRectValue].size;
CGRect viewFrame = scrollView.frame;
viewFrame.size.height = keyboardSize.height;
CGRect textFieldRect = activeField.frame;
[scrollView scrollRectToVisible:textFieldRect animated:YES];
keyboardShown = YES;
}
- (void)keyboardWasHidden:(NSNotification *)notification {
NSDictionary *info = [notification userInfo];
NSValue *aValue = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
CGSize keyboardSize = [aValue CGRectValue].size;
CGRect viewFrame = scrollView.frame;
viewFrame.size.height += keyboardSize.height;
scrollView.frame = viewFrame;
keyboardShown = NO;
}
点击键盘的next按钮，在不同的textField之间换行
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
if ([textField returnKeyType] != UIReturnKeyDone) {
NSInteger nextTag = [textField tag] + 1;
UIView *nextTextField = [self.tableView viewWithTag:nextTag];
[nextTextField becomeFirstResponder];
}else {
[textField resignFirstResponder];
}
return YES;
}
设置日期格式
dateFormatter = [[NSDateFormatter alloc]init];
dateFormatter.locale = [NSLocale currentLocale];
dateFormatter.calendar = [NSCalendar autoupdatingCurrentCalendar];
dateFormatter.timeZone = [NSTimeZone defaultTimeZone];
dateFormatter.dateStyle = NSDateFormatterShortStyle;
NSLog(@"%@",[dateFormatter stringFromDate:[NSDate date]]);
加载大量图片的时候，可以使用
NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"icon" ofType:@"png"];
UIImage *myImage = [UIImage imageWithContentsOfFile:imagePath];
有时候在iPhone游戏中，既要播放背景音乐，同时又要播放比如枪的开火音效。
NSString *musicFilePath = [[NSBundle mainBundle] pathForResource:@"xx" ofType:@"wav"];
NSURL *musicURL = [NSURL fileURLWithPath:musicFilePath];
AVAudioPlayer *musicPlayer = [[AVAudioPlayer alloc]initWithContentsOfURL:musicURL error:nil];
[musicPlayer prepareToPlay];
musicPlayer.volume = 1;
musicPlayer.numberOfLoops = -1;//-1表示一直循环
从通讯录中读取电话号码，去掉数字之间的-
NSString *originalString = @"(123)123123abc";
NSMutableString *strippedString = [NSMutableString stringWithCapacity:originalString.length];
NSScanner *scanner = [NSScanner scannerWithString:originalString];
NSCharacterSet *numbers = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];
while ([scanner isAtEnd] == NO) {
NSString *buffer;
if ([scanner scanCharactersFromSet:numbers intoString:&buffer]) {
[strippedString appendString:buffer];
}else {
scanner.scanLocation = [scanner scanLocation] + 1;
}
}
NSLog(@"%@",strippedString);
字符串是否为空
- (BOOL) isBlankString:(NSString *)string {
if (string == nil || string == NULL) {
return YES;
}
if ([string isKindOfClass:[NSNull class]]) {
return YES;
}
if ([[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] length]==0) {
return YES;
}
return NO;
}
正则判断：字符串只包含字母和数字
NSString *myString = @"Letter1234";
NSString *regex = @"[a-z][A-Z][0-9]";
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex];
if ([predicate evaluateWithObject:myString]) {
//implement
}
设置UITableView的滚动条颜色
self.tableView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
网络编程
开发web等网络应用程序的时候，需要确认网络环境，连接情况等信息。如果没有处理它们，是不会通过apple的审查的。
系统自带的网络检查是原生的，AFNetworking也为我们添加了相关检测机制，所以这个直接在介绍AFNetworking的时候详解吧。
使用NSURLConnection下载数据
1. 创建对象
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.baidu.com"]];
[NSURLConnection connectionWithRequest:request delegate:self];
2. NSURLConnection delegate 委托方法
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
}
3. 实现委托方法
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
self.receiveData.length = 0;//先清空数据
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[self.receiveData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
//错误处理
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
NSString *returnString = [[NSString alloc]initWithData:self.receiveData encoding:NSUTF8StringEncoding];
firstTimeDownloaded = YES;
}
隐藏状态栏
[UIApplication sharedApplication].statusBarHidden = YES;
.m文件与.mm文件的区别
.m文件是objectivec文件
.mm文件相当于c++或者c文件
Safari其实没有把内存的缓存写到存储卡上
读取一般性文件
- (void)readFromTXT {
NSString *tmp;
NSArray *lines;//将文件转化为一行一行的
lines = [[NSString stringWithContentsOfFile:@"testFileReadLines.txt"] componentsSeparatedByString:@"\\n"];
NSEnumerator *nse = [lines objectEnumerator];
//读取<>里的内容
while (tmp == [nse nextObject]) {
NSString *stringBetweenBrackets = nil;
NSScanner *scanner = [NSScanner scannerWithString:tmp];
[scanner scanUpToString:@"<" intoString:nil];
[scanner scanString:@"<" intoString:nil];
[scanner scanUpToString:@">" intoString:&stringBetweenBrackets];
NSLog(@"%@",[stringBetweenBrackets description]);
}
}
隐藏UINavigationBar
[self.navigationController setNavigationBarHidden:YES animated:YES];
调用电话，短信，邮件
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"mailto:apple@mac.com?Subject=hello"]];
sms://调用短信
tel://调用电话
itms://打开MobileStore.app
获取版本信息
UIDevice *myDevice = [UIDevice currentDevice];
NSString *systemVersion = myDevice.systemVersion;
UIWebView的使用
<UIWebViewDelegate>
webView.delegate = self;
(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
NSURL *url = request.URL;
NSString *urlStirng = url.absoluteString;
NSLog(@"%@",urlStirng);
return YES;
}
UIButton的title和image不能同时显示
UINavigationItem也是
不要再语言包里面设置空格
NSNotificationCenter带参数发送
MPMoviePlayerController *theMovie = [[MPMoviePlayerController alloc]initWithContentURL:[NSURL fileURLWithPath:moviePath]];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(myMovieFinishedCallback:) name:MPMoviePlayerPlaybackDidFinishNotification object:theMovie];
[theMovie play];
- (void)myMovieFinishedCallback:(NSNotification *)aNotification {
MPMoviePlayerController *theMovie = [aNotification object];
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:theMovie];
}
延迟一段时间执行某个函数
[self performSelector:@selector(dismissModal) withObject:self afterDelay:1.0];
用NSDateFormatter调整时间格式代码
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
dateFormatter.dateFormat = @"yyyy-MM-dd HH:mm:ss";
NSString *currentDateStr = [dateFormatter stringFromDate:[NSDate date]];
UIView设置成圆角的方法
mainView.layer.cornerRadius = 6;
mainView.layer.masksToBounds = YES;
objectivec 内存管理
- 一个对象可以有一个或多个拥有者
- 当它一个拥有者都没有的时候，它就会被回收
- 如果想保留一个对象不被回收，你就必须成为它的拥有者
关键字
- alloc
为对象分配内存，计数设为1，并返回此对象。
- copy
复制一个对象，此对象计数为1，返回此对象。你将成为此克隆对象的拥有者。 - retain
对象计数+1，并成为次对象的拥有者。 - release
对象计数-1，并丢掉此对象。 - autorelease
在未来的某一个时刻，对象计数-1。并在未来的某个时间放弃此对象。
原则
- 一个代码块内要确保copy，alloc 和 retain 的使用数量与 release 和 autorelease 的数量相等。
- 在使用以 alloc 或 new 开头或包含 copy 的方法，或 retain 一个对象时，你将会编程它的拥有者。
- 实现 dealloc 方法，这是系统当 retain -> 0 的时候，自动调用的。手动调用会引起 retain count 计数错误（多一次的 release）。
iPhone 更改键盘右下角按键的 type
SearchBar *mySearchBar = [[UISearchBar alloc]init];
mySearchBar.frame = CGRectMake(0, 0, self.view.bounds.size.width, 44);
mySearchBar.placeholder = @"placeholderString";
mySearchBar.delegate = self;
[self.view addSubview:mySearchBar];
UITextField *searchField = [[mySearchBar subviews] lastObject];
searchField.returnKeyType = UIReturnKeyDone;
tableView左滑出多个按钮
- (NSArray *)tableView:(UITableView *)tableView editActionsForRowAtIndexPath:(NSIndexPath *)indexPath
{
//删除按钮
UITableViewRowAction *deleteRowAction = [UITableViewRowAction rowActionWithStyle:UITableViewRowActionStyleDefault title:@"删除" handler:^(UITableViewRowAction * _Nonnull action, NSIndexPath * _Nonnull indexPath){
[_dataArray removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationAutomatic];
}];
//置顶按钮
UITableViewRowAction *toTopRowAction = [UITableViewRowAction rowActionWithStyle:UITableViewRowActionStyleDefault title:@"置顶" handler:^(UITableViewRowAction * _Nonnull action, NSIndexPath * _Nonnull indexPath){
NSLog(@"置顶");
}];
toTopRowAction.backgroundColor = [UIColor orangeColor];
//其他按钮
UITableViewRowAction *otherRowAction = [UITableViewRowAction rowActionWithStyle:UITableViewRowActionStyleDefault title:@"其他" handler:^(UITableViewRowAction * _Nonnull action, NSIndexPath * _Nonnull indexPath){
NSLog(@"其他");
}];
otherRowAction.backgroundColor = [UIColor lightGrayColor];
//返回按钮数组
return @[deleteRowAction, toTopRowAction, otherRowAction];
}
给图片增加模糊效果
//加模糊效果，image是图片，blur是模糊度
+ (UIImage *)blurryImage:(UIImage *)image withBlurLevel:(CGFloat)blur {
//模糊度,
if ((blur < 0.1f) || (blur > 2.0f)) {
blur = 0.1f;
}
//boxSize必须大于0
int boxSize = (int)(blur * 100);
boxSize -= (boxSize % 2) + 1;
NSLog(@"boxSize:%i",boxSize);
//图像处理
CGImageRef img = image.CGImage;
//图像缓存,输入缓存，输出缓存
vImage_Buffer inBuffer, outBuffer;
vImage_Error error;
//像素缓存
void *pixelBuffer;
//数据源提供者，Defines an opaque type that supplies Quartz with data.
CGDataProviderRef inProvider = CGImageGetDataProvider(img);
// provider’s data.
CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
//宽，高，字节/行，data
inBuffer.width = CGImageGetWidth(img);
inBuffer.height = CGImageGetHeight(img);
inBuffer.rowBytes = CGImageGetBytesPerRow(img);
inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
//像数缓存，字节行*图片高
pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
outBuffer.data = pixelBuffer;
outBuffer.width = CGImageGetWidth(img);
outBuffer.height = CGImageGetHeight(img);
outBuffer.rowBytes = CGImageGetBytesPerRow(img);
// 第三个中间的缓存区,抗锯齿的效果
void *pixelBuffer2 = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
vImage_Buffer outBuffer2;
outBuffer2.data = pixelBuffer2;
outBuffer2.width = CGImageGetWidth(img);
outBuffer2.height = CGImageGetHeight(img);
outBuffer2.rowBytes = CGImageGetBytesPerRow(img);
//Convolves a region of interest within an ARGB8888 source image by an implicit M x N kernel that has the effect of a box filter.
error = vImageBoxConvolve_ARGB8888(&inBuffer;, &outBuffer2;, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
error = vImageBoxConvolve_ARGB8888(&outBuffer2;, &inBuffer;, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
error = vImageBoxConvolve_ARGB8888(&inBuffer;, &outBuffer;, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
if (error) {
NSLog(@"error from convolution %ld", error);
}
// NSLog(@"字节组成部分：%zu",CGImageGetBitsPerComponent(img));
//颜色空间DeviceRGB
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
//用图片创建上下文,CGImageGetBitsPerComponent(img),7,8
CGContextRef ctx = CGBitmapContextCreate(
outBuffer.data,
outBuffer.width,
outBuffer.height,
8,
outBuffer.rowBytes,
colorSpace,
CGImageGetBitmapInfo(image.CGImage));
//根据上下文，处理过的图片，重新组件
CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
//clean up
CGContextRelease(ctx);
CGColorSpaceRelease(colorSpace);
free(pixelBuffer);
free(pixelBuffer2);
CFRelease(inBitmapData);
CGImageRelease(imageRef);
return returnImage;
}
网易新闻头部滚动切换
- (void)titleButtonDidClick:(UIButton *)titleButton
{
self.mainScrollView.contentOffset = CGPointMake(kScreenWidth * titleButton.tag, 0);
[UIView animateWithDuration:0.5 animations:^{
if (self.titleScrollView.contentOffset.x >= 0) {
self.titleScrollView.contentOffset = CGPointMake(titleButton.x - 150, 0);
}
// 先改变contentOffset，若偏移则修正
if (self.titleScrollView.contentOffset.x <= 0) {
self.titleScrollView.contentOffset = CGPointZero;
}
if (self.titleScrollView.contentOffset.x >= 2 * 900 - kScreenWidth) {
self.titleScrollView.contentOffset = CGPointMake(2 * 900 - kScreenWidth, 0);
}
}];
}
七牛上传图片的简单封装
#import "QiNiuTool.h"
#import "JKRAccountTool.h"
#import "JKRAccount.h"
#import "QiniuSDK.h"
#import "QiNiuUpLoadResult.h"
#import <UIKit/UIKit.h>
@implementation QiNiuTool
+ (void)uploadImages:(NSArray *)images complete:(void (^)(NSDictionary *))complete
{
QNUploadManager *qnm = [[QNUploadManager alloc] init];
NSDateFormatter *mattter = [[NSDateFormatter alloc]init];
[mattter setDateFormat:@"yyyyMMddHHmmss"];
NSString *Nowdate = [mattter stringFromDate:[NSDate date]];
QiNiuUpLoadResult *result = [[QiNiuUpLoadResult alloc] init];
__block int count = 0;
for (int i = 0; i < images.count; i++) {
UIImage *image = images[i];
NSData *uploadData = UIImageJPEGRepresentation(image, 1);
//这里对大图片做了压缩，不需要的话下面直接传uploadData就好
NSData *cutdownData = nil;
if (uploadData.length < 9999) {
cutdownData = UIImageJPEGRepresentation(image, 1.0);
} else if (uploadData.length < 99999) {
cutdownData = UIImageJPEGRepresentation(image, 0.6);
} else {
cutdownData = UIImageJPEGRepresentation(image, 0.3);
}
//[JKRAccountTool getAccount].token:token
[qnm putData:cutdownData key:[NSString stringWithFormat:@"%@%d", Nowdate, i+1] token:[JKRAccountTool getAccount].token complete:^(QNResponseInfo *info, NSString *key, NSDictionary *resp) {
count++;
NSString *resultKey = [NSString stringWithFormat:@"%d",i];
result.keys[resultKey] = [resp objectForKey:@"key"];
if (count == images.count) {
complete(result.keys);
}
} option:nil];
}
}
@end
导航条渐隐渐现
[_tableView addObserver: self forKeyPath: @"contentOffset" options: NSKeyValueObservingOptionNew context:nil];
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context{
CGFloat offset=_tableView.contentOffset.y;
NSLog(@"offset:%f",offset);//越来越大 想要实现效果：一开始全显示，后来颜色变浅
CGFloat delta=1-offset/100.f;
delta=MIN(1,delta);
NSLog(@"%f",delta);
self.navigationController.navigationBar.alpha=MIN(1,delta);
}
图片压缩
用法：UIImage *yourImage= [self imageWithImageSimple:image scaledToSize:CGSizeMake(210.0, 210.0)];
//压缩图片
- (UIImage*)imageWithImageSimple:(UIImage*)image scaledToSize:(CGSize)newSize
{
// Create a graphics image context
UIGraphicsBeginImageContext(newSize);
// Tell the old image to draw in this newcontext, with the desired
// new size
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
// Get the new image from the context
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
// End the context
UIGraphicsEndImageContext();
// Return the new image.
return newImage;
}
图片裁剪，类似新浪微博小图显示效果
CGSize asize = CGSizeMake(300, 300);
UIImage *newimage;
UIImage *image = [UIImage imageNamed:@""];
if (nil == image) {
newimage = nil;
}
else{
CGSize oldsize = image.size;
CGRect rect;
if (asize.width/asize.height > oldsize.width/oldsize.height) {
rect.size.width = asize.width;
rect.size.height = asize.width*oldsize.height/oldsize.width;
rect.origin.x = 0;
rect.origin.y = (asize.height - rect.size.height)/2;
}
else{
rect.size.width = asize.height*oldsize.width/oldsize.height;
rect.size.height = asize.height;
rect.origin.x = (asize.width - rect.size.width)/2;
rect.origin.y = 0;
}
UIGraphicsBeginImageContext(asize);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextClipToRect(context, CGRectMake(0, 0, asize.width, asize.height));
CGContextSetFillColorWithColor(context, [[UIColor clearColor] CGColor]);
UIRectFill(CGRectMake(0, 0, asize.width, asize.height));//clear background
[image drawInRect:rect];
newimage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
UIImageView * imgView = [[UIImageView alloc]initWithFrame:CGRectMake(10, 10, 100, 100)];
imgView.image = newimage;
[self.view addSubview:imgView];
把时间戳转换为时间
+ (NSDate *)dateWithTimeIntervalInMilliSecondSince1970:(double)timeIntervalInMilliSecond {
NSDate *ret = nil;
double timeInterval = timeIntervalInMilliSecond;
// judge if the argument is in secconds(for former data structure).
if(timeIntervalInMilliSecond > 140000000000) {
timeInterval = timeIntervalInMilliSecond / 1000;
}
ret = [NSDate dateWithTimeIntervalSince1970:timeInterval];
return ret;
}
自定义cell中获取不到cell实际大小的办法
-(void)drawRect:(CGRect)rect {
// 重写此方法，并在此方法中获取
CGFloat width = self.frame.size.width;
}
长按图标抖动
-(void)longPress:(UILongPressGestureRecognizer*)longPress
{
if (longPress.state==UIGestureRecognizerStateBegan) {
CAKeyframeAnimation* anim=[CAKeyframeAnimation animation];
anim.keyPath=@"transform.rotation";
anim.values=@[@(angelToRandian(-7)),@(angelToRandian(7)),@(angelToRandian(-7))];
anim.repeatCount=MAXFLOAT;
anim.duration=0.2;
[self.imageView.layer addAnimation:anim forKey:nil];
self.btn.hidden=NO;
}
}
阿拉伯数字转化为汉语数字
+(NSString *)translation:(NSString *)arebic
{ NSString *str = arebic;
NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"];
NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];
NSArray *digits = @[@"个",@"十",@"百",@"千",@"万",@"十",@"百",@"千",@"亿",@"十",@"百",@"千",@"兆"];
NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:chinese_numerals forKeys:arabic_numerals];
NSMutableArray *sums = [NSMutableArray array];
for (int i = 0; i < str.length; i ++) {
NSString *substr = [str substringWithRange:NSMakeRange(i, 1)];
NSString *a = [dictionary objectForKey:substr];
NSString *b = digits[str.length -i-1];
NSString *sum = [a stringByAppendingString:b];
if ([a isEqualToString:chinese_numerals[9]])
{
if([b isEqualToString:digits[4]] || [b isEqualToString:digits[8]])
{
sum = b;
if ([[sums lastObject] isEqualToString:chinese_numerals[9]])
{
[sums removeLastObject];
}
}else
{
sum = chinese_numerals[9];
}
if ([[sums lastObject] isEqualToString:sum])
{
continue;
}
}
[sums addObject:sum];
}
NSString *sumStr = [sums componentsJoinedByString:@""];
NSString *chinese = [sumStr substringToIndex:sumStr.length-1];
NSLog(@"%@",str);
NSLog(@"%@",chinese);
return chinese;
}
两种方法删除NSUserDefaults所有记录
//方法一
NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];
//方法二
- (void)resetDefaults {
NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
NSDictionary * dict = [defs dictionaryRepresentation];
for (id key in dict) {
[defs removeObjectForKey:key];
}
[defs synchronize];
}
截屏 全图
- (UIImage *)imageFromView: (UIView *) theView
{
UIGraphicsBeginImageContext(theView.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[theView.layer renderInContext:context];
UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return theImage;
}
判断是否用户开启了定位服务
if ([CLLocationManager locationServicesEnabled] &&
([CLLocationManager authorizationStatus] == kCLAuthorizationStatusAuthorized
|| [CLLocationManager authorizationStatus] == kCLAuthorizationStatusNotDetermined)) {
//定位功能可用，开始定位
_locationManger = [[CLLocationManager alloc] init];
locationManger.delegate = self;
[locationManger startUpdatingLocation];
}
else if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusDenied){
NSlog("定位功能不可用，提示用户或忽略");
}
图片旋转
UIImage * image = [UIImage imageNamed:@"iphone.png"];
NSData * tempData;
if (UIImagePNGRepresentation(image)) {
tempData = UIImagePNGRepresentation(image);
NSLog(@"%@",tempData);
}
else{
tempData = UIImageJPEGRepresentation(image, 1);
}
CIImage * iImg = [CIImage imageWithData:tempData];
UIImage * tImg = [UIImage imageWithCIImage:iImg scale:1 orientation:UIImageOrientationRight];
NSLog(@"%@",UIImagePNGRepresentation(tImg));
UIImageView * imageView = [[UIImageView alloc]initWithFrame:CGRectMake(10, 200, 200, 80)];
imageView.image = tImg;
[self.view addSubview:imageView];
去除UIImageView锯齿
imageView.layer.shouldRasterize = YES;
判断两个日期之间的间隔
NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyyMMddHHmmss"];
NSDate* toDate = [dateFormatter dateFromString:@"19700608142033"];
NSDate* startDate = [ [ NSDate alloc] init ];
NSCalendar* chineseClendar = [ [ NSCalendar alloc ] initWithCalendarIdentifier:NSGregorianCalendar ];
NSUInteger unitFlags = NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit | NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit;
NSDateComponents *cps = [ chineseClendar components:unitFlags fromDate:startDate toDate:toDate options:0];
NSInteger diffYear = [cps year];
NSInteger diffMon = [cps month];
NSInteger diffDay = [cps day];
NSInteger diffHour = [cps hour];
NSInteger diffMin = [cps minute];
NSInteger diffSec = [cps second];
NSLog(@" From Now to %@, diff: Years: %d Months: %d, Days; %d, Hours: %d, Mins:%d, sec:%d", [toDate description], diffYear, diffMon, diffDay, diffHour, diffMin,diffSec );
类似微信发送视频的流程
//获取视频的本地url或者path，对视频进行获取第一帧图片，然后初始化消息的Model，设置封面
NSString *mediaType = [editingInfo objectForKey: UIImagePickerControllerMediaType];
NSString *videoPath;
NSURL *videoUrl;
if (CFStringCompare ((__bridge CFStringRef) mediaType, kUTTypeMovie, 0) == kCFCompareEqualTo) {
videoUrl = (NSURL*)[editingInfo objectForKey:UIImagePickerControllerMediaURL];
videoPath = [videoUrl path];
AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoUrl options:nil];
NSParameterAssert(asset);
AVAssetImageGenerator *assetImageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
assetImageGenerator.appliesPreferredTrackTransform = YES;
assetImageGenerator.apertureMode = AVAssetImageGeneratorApertureModeEncodedPixels;
CGImageRef thumbnailImageRef = NULL;
CFTimeInterval thumbnailImageTime = 0;
NSError *thumbnailImageGenerationError = nil;
thumbnailImageRef = [assetImageGenerator copyCGImageAtTime:CMTimeMake(thumbnailImageTime, 60) actualTime:NULL error:&thumbnailImageGenerationError;];
if (!thumbnailImageRef)
NSLog(@"thumbnailImageGenerationError %@", thumbnailImageGenerationError);
UIImage *thumbnailImage = thumbnailImageRef ? [[UIImage alloc] initWithCGImage:thumbnailImageRef] : nil;
XHMessage *videoMessage = [[XHMessage alloc] initWithVideoConverPhoto:thumbnailImage videoPath:videoPath videoUrl:nil sender:@"Jack" timestamp:[NSDate date]];
[weakSelf addMessage:videoMessage];
}
刷新某行cell的方法
//有时候只需要刷新某行的cell的数据，完全没必要调用[tableView reloadData]刷新整个列表的数据，调用以下方法即可。
NSIndexPath *indexPath_1=[NSIndexPath indexPathForRow:1 inSection:0];
NSArray *indexArray=[NSArray arrayWithObject:indexPath_1];
[myTableView reloadRowsAtIndexPaths:indexArray withRowAnimation:UITableViewRowAnimationAutomatic];
由身份证号码返回性别
-(NSString *)sexStrFromIdentityCard:(NSString *)numberStr{
NSString *result = nil;
BOOL isAllNumber = YES;
if([numberStr length]<17)
return result;
//**截取第17为性别识别符
NSString *fontNumer = [numberStr substringWithRange:NSMakeRange(16, 1)];
//**检测是否是数字;
const char *str = [fontNumer UTF8String];
const char *p = str;
while (*p!='\\0') {
if(!(*p>='0'&&*p<='9'))
isAllNumber = NO;
p++;
}
if(!isAllNumber)
return result;
int sexNumber = [fontNumer integerValue];
if(sexNumber%2==1)
result = @"男";
///result = @"M";
else if (sexNumber%2==0)
result = @"女";
//result = @"F";
return result;
}
数组随机重新排列
+ (NSArray *)getRandomWithPosition:(NSInteger)position positionContent:(id)positionContent array:(NSArray *)baseArray {
NSMutableArray *resultArray = [NSMutableArray arrayWithCapacity:baseArray.count];
NSMutableArray *tempBaseArray = [NSMutableArray arrayWithArray:baseArray];
while ([tempBaseArray count]) {
NSInteger range = [tempBaseArray count];
id string = [tempBaseArray objectAtIndex:arc4random()%range];
[resultArray addObject:string];
[tempBaseArray removeObject:string];
}
NSUInteger index = [resultArray indexOfObject:positionContent];
[resultArray exchangeObjectAtIndex:index withObjectAtIndex:position - 1];
return resultArray;
}
利用陀螺仪实现更真实的微信摇一摇动画
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//想摇你的手机嘛？就写在这，然后，然后，没有然后了
application.applicationSupportsShakeToEdit=YES;
}
-(void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event {
if(motion==UIEventSubtypeMotionShake) {
// 真实一点的摇动动画
[self addAnimations];
// 播放声音
AudioServicesPlaySystemSound (soundID);
}
}
- (void)addAnimations {
CABasicAnimation *translation = [CABasicAnimation animationWithKeyPath:@"transform"];
translation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
translation.toValue=[NSValue valueWithCATransform3D:CATransform3DMakeRotation(-M_PI_4, 0, 0, 100)];
translation.duration = 0.2;
translation.repeatCount = 2;
translation.autoreverses = YES;
[shake.layer addAnimation:translation forKey:@"translation"];
}
GIF图片解析
+ (NSMutableArray *)praseGIFDataToImageArray:(NSData *)data;
{
NSMutableArray *frames = [[NSMutableArray alloc] init];
CGImageSourceRef src = CGImageSourceCreateWithData((CFDataRef)data, NULL);
CGFloat animationTime = 0.f;
if (src) {
size_t l = CGImageSourceGetCount(src);
frames = [NSMutableArray arrayWithCapacity:l];
for (size_t i = 0; i < l; i++) {
CGImageRef img = CGImageSourceCreateImageAtIndex(src, i, NULL);
NSDictionary *properties = (NSDictionary *)CGImageSourceCopyPropertiesAtIndex(src, i, NULL);
NSDictionary *frameProperties = [properties objectForKey:(NSString *)kCGImagePropertyGIFDictionary];
NSNumber *delayTime = [frameProperties objectForKey:(NSString *)kCGImagePropertyGIFUnclampedDelayTime];
animationTime += [delayTime floatValue];
if (img) {
[frames addObject:[UIImage imageWithCGImage:img]];
CGImageRelease(img);
}
}
CFRelease(src);
}
return frames;
}
在后台播放音乐
//1. 在Info.plist中，添加"Required background modes"键，其值设置是“App plays audio"
//2. 在播放器播放音乐的代码所在处，添加如下两段代码（当然，前提是已经添加了AVFoundation框架）
//添加后台播放代码：
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setActive:YES error:nil];
[session setCategory:AVAudioSessionCategoryPlayback error:nil];
//以及设置app支持接受远程控制事件代码。设置app支持接受远程控制事件，
//其实就是在dock中可以显示应用程序图标，同时点击该图片时，打开app。
//或者锁屏时，双击home键，屏幕上方出现应用程序播放控制按钮。
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
//用下列代码播放音乐，测试后台播放
// 创建播放器
AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
[url release];
[player prepareToPlay];
[player setVolume:1];
player.numberOfLoops = -1; //设置音乐播放次数 -1为一直循环
[player play]; //播放
本博客所有内容采用 知识共享署名-非商业性使用-相同方式共享 4.0 国际许可协议 进行许可
转载文章请注明：iOS-Skill技巧 - https://yimouleng.com/2014/04/23/ios-skill%e6%8a%80%e5%b7%a7/
分类: iOS开发
丶伊眸冷
静水流深，沧笙踏歌；三生阴晴圆缺，一朝悲欢离合。
