iOS開發中一些有用的小代碼

1.判斷郵箱格式是否正確的代碼：

// 利用正則表達式驗證

-(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.圖片壓縮

用法： UIImage *yourImage= [self imageWithImageSimple:image scaledToSize:CGSizeMake(210.0, 210.0)];

// 壓縮圖片

- (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.親測可用的圖片上傳代碼

- (IBAction)uploadButton:(id)sender {
    UIImage *image = [UIImage imageNamed:@"1.jpg"]; //圖片名
    NSData *imageData = UIImageJPEGRepresentation(image,0.5);//壓縮比例
    NSLog(@"字節數:%i",[imageData length]);
    // post url
    NSString *urlString = @"http://192.168.1.113:8090/text/UploadServlet";
    //服務器地址
    // 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]]; //上傳上去的圖片名字
    [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-測試輸出：%@",returnString);
}

 

4.給imageView加載圖片

UIImage *myImage = [UIImage imageNamed:@"1.jpg"];
[imageView setImage:myImage];
[self.view addSubview:imageView];

 

5.對圖庫的操作

選擇相冊：

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];

 選擇完畢：

-(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 為自己定義的方法，編輯選取照片后要實現的效果

取消選擇：

-(void)imagePickerControllerDIdCancel:(UIImagePickerController*)picker
{
    [picker dismissModalViewControllerAnimated:YES];
}

 

6.跳到下個View

nextWebView = [[WEBViewController alloc] initWithNibName:@"WEBViewController" bundle:nil];
[self presentModalViewController:nextWebView animated:YES];

 

7.創建一個UIBarButton右邊按鈕 

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

 

8.設置navigationBar隱藏

self.navigationController.navigationBarHidden = YES;//

 

  9.UIlabel多行文字自動換行 （自動折行）

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!";
//背景顏色為紅色
label.backgroundColor = [UIColor redColor];
//設置字體顏色為白色
label.textColor = [UIColor whiteColor];
//文字居中顯示
label.textAlignment = UITextAlignmentCenter;
//自動折行設置
label.lineBreakMode = UILineBreakModeWordWrap;
label.numberOfLines = 0;

 

10.代碼生成Button 

CGRect frame = CGRectMake(0, 400, 72.0, 37.0);
UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
button.frame = frame;
[button setTitle:@"新添加的按鈕" forState: UIControlStateNormal];
button.backgroundColor = [UIColor clearColor];
button.tag = 2000;
[button addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];

 

11.讓某個控件在View的中心位置顯示：

 label.center = self.view.center；//（某個控件，比如label，View）

 

12.自定義text各種效果：

cell.backgroundColor = [UIColorscrollViewTexturedBackgroundColor];
//設置文字的字體
cell.textLabel.font = [UIFont fontWithName:@"AmericanTypewriter" size:100.0f];
//設置文字的顏色
cell.textLabel.textColor = [UIColor orangeColor];
//設置文字的背景顏色
cell.textLabel.shadowColor = [UIColor whiteColor];
//設置文字的顯示位置
cell.textLabel.textAlignment = UITextAlignmentCenter;

 

13.隱藏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)];//這個地方的大小要自己調整，以適應alertview的背景顏色的大小。
   theImage = UIGraphicsGetImageFromCurrentImageContext();   
   UIGraphicsEndImageContext();
   theAlert.layer.contents = (id)[theImage CGImage];

 

15.鍵盤透明：

textField.keyboardAppearance = UIKeyboardAppearanceAlert;

 

16.狀態欄的網絡活動風火輪是否旋轉：

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES ; //默認值是NO。

 

17.截取屏幕圖片：

//創建一個基於位圖的圖形上下文並指定大小為CGSizeMake(200,400)
UIGraphicsBeginImageContext(CGSizeMake(200,400)); 
//renderInContext 呈現接受者及其子范圍到指定的上下文
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    //返回一個基於當前圖形上下文的圖片
 UIImage *aImage = UIGraphicsGetImageFromCurrentImageContext();
  //移除棧頂的基於當前位圖的圖形上下文
UIGraphicsEndImageContext();
//以png格式返回指定圖片的數據
imageData = UIImagePNGRepresentation(aImage);

 

18.更改cell選中的背景：

  UIView *myview = [[UIView alloc] init];
  myview.frame = CGRectMake(0, 0, 320, 47);
  myview.backgroundColor = [UIColorcolorWithPatternImage:[UIImage imageNamed:@"0006.png"]];
  cell.selectedBackgroundView = myview;

 

19.顯示圖片：

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.能讓圖片適應框的大小（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. 實現點擊圖片進行跳轉的代碼：（生成一個帶有背景圖片的button，給button綁定想要的事件）

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.鍵盤回收：

-（IBAction）textFieldDoneEditing：（id）sender{
      [sender resighFirstRespond]；
}

 通過點擊背景回收鍵盤：（兩個都得添加）

-（IBAction）textFieldDoneEditing：（id）sender{
　　[sender resighFirstRespond]；
}
-（IBAction）backgroundTapped：（id）sender{
　　[nameField resignFirstRespond];
　　[numberField resignFirstRespond];
}