iOS高级开发实战技巧讲解
来源:互联网 发布:sql视图删除数据 编辑:程序博客网 时间:2024/06/18 04:51
Segment Fault:http://segmentfault.com/a/1190000003505115
github:https://github.com/koknine (终于改成以前的了)
(简书还有Segment Fault的markdown编辑很好用)
iOS开发过程中,总有那么一些个小问题让人纠结,它们不会让程序崩溃,但是会让人崩溃。除此之外,还将分享一些细节现在我通过自己的总结以及从其他地方的引用,来总结一下一些常见小问题。
本篇长期更新,多积累,多奉献,同时感谢其中一些文章的作者的整理,感谢!
iOS高级开发实战讲解
这是我在网上搜索到的iOS高级开发实战讲解,由于原文不是很方便浏览,所以我在这里整理一部分出来,方便查阅,同时谢谢原作者。
这里我不是每一个都收录进来,这里只是放出一部分,有些用的太多,我就没整理了,大家如果想看可以去看原文。
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);
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;}
iOS的动画以及自定义图形,开个专栏总结。
隐藏状态栏
[UIApplication sharedApplication].statusBarHidden = YES;
.m文件与.mm文件的区别
.m文件是objective-c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 *urlString = url.absoluteString; NSLog(@"%@",urlString); 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;
Objective-C 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;
原文链接:http://www.jianshu.com/p/28f7d1f963a7
著作权归作者所有,转载请联系作者获得授权,并标注“简书作者”。
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