iOS开发中一些有用的小代码

// 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 : UIButtonTypeR

补充：移动开发 , IOS ,