iOS 17个常用代码整理

转自 http://blog.youkuaiyun.com/jinglijun/article/details/8351883

1.判断邮箱格式是否正确的代码：  
    //利用正则表达式验证  
    -(BOOL)isValidateEmail:(NSString *)email  
    {  
        NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";  
        NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES%@",emailRegex];  
        return [emailTest evaluateWithObject:email];  
    }  
    2.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;  
    }  
    3.亲测可用的图片上传代码  
    - (IBAction)uploadButton:(id)sender {  
        UIImage *image = [UIImage imageNamed:@"1.jpg"]; //图片名  
        NSData *imageData = UIImageJPEGRepresentation(image,0.5);//压缩比例  
        NSLog(@"字节数:%i",[imageData length]);  
        // post url  
        NSString *urlString = @"http://192.168.1.113:8090/text/UploadServlet";  
        //服务器地址  
        // setting up the request object now  
        NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;  
        [request setURL:[NSURL URLWithString:urlString]];  
        [request setHTTPMethod:@"POST"];  
        //  
        NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];  
        NSString *contentType = [NSString stringWithFormat:@"multipart/form-data;boundary=%@",boundary];  
        [request addValue:contentType forHTTPHeaderField: @"Content-Type"];  
        //  
        NSMutableData *body = [NSMutableData data];  
        [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];  
        [body appendData:[[NSString stringWithString:@"Content-Disposition:form-data; name=\"userfile\"; filename=\"2.png\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; //上传上去的图片名字  
        [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];  
        [body appendData:[NSData dataWithData:imageData]];  
        [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];  
        [request setHTTPBody:body];  
        // NSLog(@"1-body:%@",body);  
        NSLog(@"2-request:%@",request);  
        NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];  
        NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];  
        NSLog(@"3-测试输出：%@",returnString);  
     4.给imageView加载图片  
        UIImage *myImage = [UIImage imageNamed:@"1.jpg"];  
        [imageView setImage:myImage];  
        [self.view addSubview:imageView];  
     5.对图库的操作  
        选择相册：  
        UIImagePickerControllerSourceTypesourceType=UIImagePickerControllerSourceTypeCamera;  
        if (![UIImagePickerControllerisSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {  
            sourceType=UIImagePickerControllerSourceTypePhotoLibrary;  
        }  
        UIImagePickerController * picker = [[UIImagePickerControlleralloc]init];  
        picker.delegate = self;  
        picker.allowsEditing=YES;  
        picker.sourceType=sourceType;  
        [self presentModalViewController:picker animated:YES];  
        选择完毕：  
        -(void)imagePickerController:(UIImagePickerController*)pickerdidFinishPickingMediaWithInfo:(NSDictionary *)info  
        {  
            [picker dismissModalViewControllerAnimated:YES];  
            UIImage * image=[info objectForKey:UIImagePickerControllerEditedImage];  
            [self performSelector:@selector(selectPic:) withObject:imageafterDelay:0.1];  
        }  
        -(void)selectPic:(UIImage*)image  
        {  
            NSLog(@"image%@",image);  
            imageView = [[UIImageView alloc] initWithImage:image];  
            imageView.frame = CGRectMake(0, 0, image.size.width, image.size.height);  
            [self.viewaddSubview:imageView];  
            [self performSelectorInBackground:@selector(detect:) withObject:nil];  
        }  
        detect为自己定义的方法，编辑选取照片后要实现的效果  
        取消选择：  
        -(void)imagePickerControllerDIdCancel:(UIImagePickerController*)picker  
        {  
            [picker dismissModalViewControllerAnimated:YES];  
        }  
      6.跳到下个View  
        nextWebView = [[WEBViewController alloc] initWithNibName:@"WEBViewController" bundle:nil];  
        [self presentModalViewController:nextWebView animated:YES];  
          
          
        //创建一个UIBarButtonItem右边按钮  
        UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithTitle:@"右边" style:UIBarButtonItemStyleDone target:self action:@selector(clickRightButton)];  
        [self.navigationItem setRightBarButtonItem:rightButton];  
        设置navigationBar隐藏  
        self.navigationController.navigationBarHidden = YES;//  
        iOS开发之UIlabel多行文字自动换行 （自动折行）  
        UIView *footerView = [[UIView alloc]initWithFrame:CGRectMake(10, 100, 300, 180)];  
        UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(10, 100, 300, 150)];  
        label.text = @"Hello world! Hello world!Hello world! Hello world! Hello world! Hello world! Hello world! Hello world!Hello world! Hello world! Hello world! Hello world! Hello world! Helloworld!";  
        //背景颜色为红色  
        label.backgroundColor = [UIColor redColor];  
        //设置字体颜色为白色  
        label.textColor = [UIColor whiteColor];  
        //文字居中显示  
        label.textAlignment = UITextAlignmentCenter;  
        //自动折行设置  
        label.lineBreakMode = UILineBreakModeWordWrap;  
        label.numberOfLines = 0;  
      7.代码生成button  
        CGRect frame = CGRectMake(0, 400, 72.0, 37.0);  
        UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];  
        button.frame = frame;  
        [button setTitle:@"新添加的按钮" forState: UIControlStateNormal];  
        button.backgroundColor = [UIColor clearColor];  
        button.tag = 2000;  
        [button addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];  
        [self.view addSubview:button];  
      8.让某个控件在View的中心位置显示：  
        （某个控件，比如label，View）label.center = self.view.center;  
      9.好看的文字处理  
        以tableView中cell的textLabel为例子：  
        cell.backgroundColor = [UIColorscrollViewTexturedBackgroundColor];  
        //设置文字的字体  
        cell.textLabel.font = [UIFont fontWithName:@"AmericanTypewriter" size:100.0f];  
        //设置文字的颜色  
        cell.textLabel.textColor = [UIColor orangeColor];  
        //设置文字的背景颜色  
        cell.textLabel.shadowColor = [UIColor whiteColor];  
        //设置文字的显示位置  
        cell.textLabel.textAlignment = UITextAlignmentCenter;  
      10. ———————-隐藏Status Bar—————————–  
        读者可能知道一个简易的方法,那就是在程序的viewDidLoad中加入  
        [[UIApplication sharedApplication]setStatusBarHidden:YES animated:NO];  
      11 更改AlertView背景  
          
        UIAlertView *theAlert = [[[UIAlertViewalloc] initWithTitle:@"Atention"  
                                                           message: @"I'm a Chinese!"  
                                                          delegate:nil  
                                                 cancelButtonTitle:@"Cancel"  
                                                 otherButtonTitles:@"Okay",nil] autorelease];  
        [theAlert show];  
        UIImage *theImage = [UIImageimageNamed:@"loveChina.png"];  
        theImage = [theImage stretchableImageWithLeftCapWidth:0topCapHeight:0];  
        CGSize theSize = [theAlert frame].size;  
        UIGraphicsBeginImageContext(theSize);  
        [theImage drawInRect:CGRectMake(5, 5, theSize.width-10, theSize.height-20)];//这个地方的大小要自己调整，以适应alertview的背景颜色的大小。  
        theImage = UIGraphicsGetImageFromCurrentImageContext();  
        UIGraphicsEndImageContext();  
        theAlert.layer.contents = (id)[theImage CGImage];  
      12. 键盘透明  
        textField.keyboardAppearance = UIKeyboardAppearanceAlert;  
          
      13.状态栏的网络活动风火轮是否旋转  
        [UIApplication sharedApplication].networkActivityIndicatorVisible，默认值是NO。  
          
      14.截取屏幕图片  
        //创建一个基于位图的图形上下文并指定大小为CGSizeMake(200,400)  
        UIGraphicsBeginImageContext(CGSizeMake(200,400));  
          
        //renderInContext 呈现接受者及其子范围到指定的上下文  
        [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];  
        //返回一个基于当前图形上下文的图片  
        UIImage *aImage = UIGraphicsGetImageFromCurrentImageContext();  
        //移除栈顶的基于当前位图的图形上下文  
        UIGraphicsEndImageContext();  
        //以png格式返回指定图片的数据  
        imageData = UIImagePNGRepresentation(aImage);  
      15.更改cell选中的背景  
        UIView *myview = [[UIView alloc] init];  
        myview.frame = CGRectMake(0, 0, 320, 47);  
        myview.backgroundColor = [UIColorcolorWithPatternImage:[UIImage imageNamed:@"0006.png"]];  
        cell.selectedBackgroundView = myview;  
      16.显示图像:  
        CGRect myImageRect = CGRectMake(0.0f, 0.0f, 320.0f, 109.0f);  
        UIImageView *myImage = [[UIImageView alloc] initWithFrame:myImageRect];  
        [myImage setImage:[UIImage imageNamed:@"myImage.png"]];  
        myImage.opaque = YES; //opaque是否透明  
        [self.view addSubview:myImage];  
      17.能让图片适应框的大小（没有确认）  
        NSString*imagePath = [[NSBundle mainBundle] pathForResource:@"XcodeCrash"ofType:@"png"];  
        UIImage *image = [[UIImage alloc]initWithContentsOfFile:imagePath];  
        UIImage *newImage= [image transformWidth:80.f height:240.f];  
        UIImageView *imageView = [[UIImageView alloc]initWithImage:newImage];  
        [newImagerelease];  
        [image release];  
        [self.view addSubview:imageView];  
      18.实现点击图片进行跳转的代码：生成一个带有背景图片的button，给button绑定想要的事件！  
        UIButton *imgButton=[[UIButton alloc]initWithFrame:CGRectMake(0, 0, 120, 120)];  
        [imgButton setBackgroundImage:(UIImage *)[self.imgArray objectAtIndex:indexPath.row] forState:UIControlStateNormal];  
        imgButton.tag=[indexPath row];  
        [imgButton addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
      

1、获取全局的Delegate对象，这样我们可以调用这个对象里的方法和变量：

[(MyAppDelegate*)[[UIApplication sharedApplication] delegate] MyMethodOrMyVariable];

2、获得程序的主Bundle：

NSBundle *bundle = [NSBundle mainBundle];

Bundle可以理解成一种文件夹，其内容遵循特定的框架。

Main Bundle一种主要用途是使用程序中的资源文件，如图片、声音、plst文件等。

NSURL *plistURL = [bundle URLForResource:@"plistFile" withExtension:@"plist"];

上面的代码获得plistFile.plist文件的路径。

3、在程序中播放声音：

首先在程序添加AudioToolbox：

其次，在有播放声音方法的.m方法添加#import：

#import<AudioToolbox/AudioToolbox.h>

接下来，播放声音的代码如下：

NSString *path = [[NSBundle mainBundle] pathForResource:@"soundFileName" ofType:@"wav"]; 

SystemSoundID soundID; 

AudioServicesCreateSystemSoundID ((__bridge CFURLRef)[NSURL fileURLWithPath:path], &soundID); 

AudioServicesPlaySystemSound (soundID); 

4、设置和获取类中属性值：

[self setValue: 变量值 forKey: 变量名];

[self valueForKey: 变量名];

5、让某一方法在未来某段时间之后执行：

[self performSelector:@selector(方法名) withObject:nil afterDelay:延迟时间（s）]; 

6、获得设备版本号：

float version = [[[UIDevice currentDevice] systemVersion] floatValue];

7、捕捉程序关闭或者进入后台事件：

UIApplication *app = [UIApplication sharedApplication];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillResignActive:) name:UIApplicationWillResignActiveNotification object:app];

applicationWillResignActive:这个方法中添加想要的操作

8、查看设备支持的字体：

for (NSString *family in [UIFont familyNames]) {

    NSLog(@"%@", family);

    for (NSString *font in [UIFont fontNamesForFamilyName:family]) {

        NSLog(@"\t%@", font);

    }

}

9、为UIImageView添加单击事件：

imageView.userInteractionEnabled = YES;

UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(yourHandlingCode:)];

[imageView addGestureRecognizer:singleTap];

10、添加多语言支持： 比如Image Picker这样的组件，它上面的按钮的文字是随着设备语言环境的改变而改变的，但是要先在工程添加语言：

11、使程序支持iTunes这样的设备，比如可以使用PC端的工具往程序的Documents中拖放文件。

12、页面切换效果设置：

controller.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

[self presentModalViewController:controller animated:YES];

可供使用的效果：

UIModalTransitionStyleCoverVertical

UIModalTransitionStyleFlipHorizontal

UIModalTransitionStyleCrossDissolve

UIModalTransitionStylePartialCurl

恢复之前的页面：

[self dismissModalViewControllerAnimated:YES];