iOS开发中一些有用的小代码

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  ];

7.创建一个UIBarButton右边按钮

UIBarButtonItem   *rightButton = [[  UIBarButtonItem     alloc  ]   initWithTitle  :  @"  右边  "     style  : UIBarButtonItemStyleDone     target  :  self     action  :  @selector  (clickRightButton)];

[  self  .  navigationItem     setRightBarButtonItem  :rightButton];

 

8.设置navigationBar隐藏

self  .  navigationController  .  navigationBarHidden   =   YES  ;//

 

9.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;

 

10.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];

 

10.2在xib文件中已经创建好Button，通过tag获取按钮 

UIButton *testButton= (UIButton*)[self.view viewWithTag:100];
    [testButton addTarget:self action:@selector(test:) forControlEvents:UIControlEventTouchUpInside];

  //按钮事件

-(void) test: (id) sender{
    UIAlertView *av = [[[UIAlertView alloc] initWithTitle:@"ceshi" message:@"test11111" delegate:nil cancelButtonTitle:@"OK"otherButtonTitles:nil] autorelease];
    [av show];
}

11.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；

 

12.自定义text各种效果：

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;

 

13.隐藏statusBar： 
在程序的  viewDidLoad  中加入 

[[UIApplication sharedApplication]setStatusBarHidden:YES animated:NO];

 

14.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];

 

15.键盘透明： 
textField.keyboardAppearance = UIKeyboardAppearanceAlert;

16.状态栏的网络活动风火轮是否旋转： 
[UIApplication sharedApplication].networkActivityIndicatorVisible  ，  默认值是  NO  。

 

17.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 = UIImagePNGR  epresentation(aImage);

 

18.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;:

19.显示图片：

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];

 

20.能让图片适应框的大小（beta）

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];

 

21.  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];

 

22.键盘回收：

1).增加一个button，相应touch down事件，隐藏键盘。这种方法，太山寨了。为了相应一个事件增加一个button太不值得的。

.h

- (IBAction)dismissKeyBoard:(id)sender;

.m

- (IBAction)dismissKeyBoard:(id)sender {

    [testText resignFirstResponder];

}

2). 第二种方法：在背景图片上添加Tap事件，相应单击处理。这种方法，很好代替了button方式，但是如果UI上没有背景图片，这种方法又回到到第一种山寨的方法行列中。

// 添加带有处理时间的背景图片

    UIImageView *backView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)];

    backView.image = [UIImage imageNamed:@"small3.png"];

    

    backView.userInteractionEnabled = YES;

    UITapGestureRecognizer *singleTouch = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissKeyboard:)];

    [backView addGestureRecognizer:singleTouch];

    

    backView.tag = 110;

    [self.view addSubview:backView];

-(void)dismissKeyboard:(id)sender{

    [text resignFirstResponder];

}

3). 在xib文件中，修改xib文件的objects属性，默认是view属性，我们可以修改为UIControl属性，从而是xib文件相应touch down事件。这种方法，缺点就是没有xib就悲剧了。

.h

- (IBAction)dimissKeyboard:(id)sender;

.m

- (IBAction)dimissKeyboard:(id)sender {

    [text resignFirstResponder];

}

23、Gif图片的解析

01 //加载gif
02
03   NSString *filePath = [[NSBundle mainBundle]pathForResource:@"bai3" ofType:@"gif"];
04
05     NSData *data = [NSData dataWithContentsOfFile:filePath];
06
07     CGImageSourceRef gif = CGImageSourceCreateWithData((CFDataRef)data, nil);
08
09  //获取gif的各种属性
10
11     CFDictionaryRef gifprops =(CGImageSourceCopyPropertiesAtIndex(gif,0,NULL));
12
13     NSLog(@"_______%@",gifprops);
14
15
16     NSInteger count =CGImageSourceGetCount(gif);
17
18     NSLog(@"________%d",count);
19
20
21    CFDictionaryRef gifDic = CFDictionaryGetValue(gifprops, kCGImagePropertyGIFDictionary);
22
23  CFDictionaryRef delay = CFDictionaryGetValue(gifDic, kCGImagePropertyGIFDelayTime);
24
25     NSLog(@"_______%@",delay);
26
27
28  //[gifDic objectForKey:(NSString *)kCGImagePropertyGIFDelayTime];
29
30     //    NSNumber * w = CFDictionaryGetValue(gifprops, @"PixelWidth");
31
32     //    NSNumber * h =CFDictionaryGetValue(gifprops, @"PixelHeight");
33
34     //    float totalDuration = delay.doubleValue * count;
35
36     //    float pixelWidth = w.intValue;
37
38     //    float pixelHeight = h.intValue;
39
40   //将gif解析成UIImage类型对象，并加进images数组中
41
42
43     NSMutableArray *images = [NSMutableArray arrayWithCapacity:count];
44
45     for(int index=0;index<count;index++)
46
47     {
48
49         CGImageRef ref = CGImageSourceCreateImageAtIndex(gif, index, nil);
50
51         UIImage *img = [UIImage imageWithCGImage:ref];
52
53         [images addObject:img];
54
55         CFRelease(ref);
56
57     }
58
59     CFRelease(gifprops);
60
61     CFRelease(gif);

    Gif的合成

01 - (void)exportAnimatedGif:(CGImageSourceRef )gif :(NSMutableArray *)images
02
03 {
04
05        NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"animated.gif"];
06
07     CGImageDestinationRef destination = CGImageDestinationCreateWithURL(( CFURLRef)[NSURL fileURLWithPath:path],
08
09                                                                         kUTTypeGIF,
10
11                                                                         images.count,
12
13                                                                         NULL);
14
15     UIImage *image;
16
17     for (int i = 0; i<images.count; i++)
18
19     {
20
21         image = images[i];
22
23         CFDictionaryRef gifprops =(CGImageSourceCopyPropertiesAtIndex(gif,i,NULL));
24
25         CFDictionaryRef gifDic = CFDictionaryGetValue(gifprops, kCGImagePropertyGIFDictionary);
26
27         NSNumber *delay = CFDictionaryGetValue(gifDic, kCGImagePropertyGIFDelayTime);
28
29         NSDictionary *gifDelay = [NSDictionary dictionaryWithObject:[NSDictionary dictionaryWithObject:delay forKey:(NSString *)kCGImagePropertyGIFDelayTime]
30
31                                                              forKey:(NSString *)kCGImagePropertyGIFDictionary];
32
33
34
35         CGImageDestinationAddImage(destination,image.CGImage, (CFDictionaryRef)gifDelay);
36
37         CGImageDestinationSetProperties(destination, ( CFDictionaryRef)gifprops);
38
39     }
40
41
42
43 //    CGImageDestinationSetProperties(destination, ( CFDictionaryRef)gifprops);
44
45     CGImageDestinationFinalize(destination);
46
47     CFRelease(destination);
48
49     NSLog(@"animated GIF file created at %@", path);
50
51
52 }

24.将一个UIView对象的内容保存为UIImage

01 + (UIImage*)imageFromView:(UIView*)view{
02
03 UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, view.layer.contentsScale);
04
05 [view.layer renderInContext:UIGraphicsGetCurrentContext()];
06
07 UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
08
09 UIGraphicsEndImageContext();
10
11 return image;
12
13 }

注意：生成的图片的scale和view的scale一致，这样才可以保证图片的效果和view显示的完全一致，使用renderInContext方法可以让subviews的内容也显示的图片里。