ios技巧，功能记录

作者: SamDing | 来源:发表于2016-06-23 20:41 被阅读175次

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

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;
}

plist文件操作

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];

从plist中获取数据赋给字典

NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"book" ofType:@"plist"];
NSDictionary *dictionary = [NSDictionary dictionaryWithContentsOfFile:plistPath];

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;

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;

ios技巧，功能记录

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