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:@"SELFMATCHES%@",emailRegex];

 

return  [emailTest  evaluateWithObject:email];

}

 

2.图片压缩

 

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

//压缩图片

- (UIImage*)imageWithImageSimple:(UIImage*)imagescaledToSize:(CGSize)newSize

{

// Create a graphics image context

UIGraphicsBeginImageCont ext(newSize);

 

// Tell the old image to draw in this newcontext, with thedesired

// new size

[image  drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];

 

// Get the new image from the context

UIImage* newImage=  UIGraphicsGetImageFromCu rrentImageContext();

 

// End the context

UIGraphicsEndImageContex t();

 

// 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=  UIImageJPEGRepresentatio n(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:@"---------------------------147378098314664998827466 41449"];

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：

UIImagePickerControllerS ourceTypesourceType=UIImagePickerControllerS ourceTypeCamera;

    if(![UIImagePickerControlleri sSourceTypeAvailable:UIImagePickerControllerS ourceTypeCamera]){

        sourceType=UIImagePickerControllerS ourceTypePhotoLibrary;

    }

    UIImagePickerController *picker = [[UIImagePickerControllera lloc]init];

    picker.delegate = self;

    picker.allowsEditing=YES;

    picker.sourceType=sourceType;

    [selfpresentModalViewControll er:picker animated:YES];

选择完毕：

  -(void)imagePickerController:(UIImagePickerController*)pickerdidFinishPickingMe diaWithInfo:(NSDictionary*)info

{

    [pickerdismissModalViewControll erAnimated:YES];

    UIImage * image=[infoobjectForKey:UIImagePickerControllerE ditedImage];

    [selfperformSelector:@selector(selectPic:)withObject:imageafterDelay:0.1];

}

  -(void)selectPic:(UIImage*)image

{

    NSLog(@"image%@",image); 

    imageView = [[UIImageViewalloc] initWithImage:image];

    imageView.frame =CGRectMake(0, 0, image.size.width, image.size.height);

[self.viewaddSubview:imageView];

    [selfperformSelectorInBackgro und:@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)imagePickerControllerDId Cancel:(UIImagePickerController*)picker
 

{

    [pickerdismissModalViewControll erAnimated:YES];

}

 

6.跳到下个View

nextWebView  =[[WEBViewController  alloc]  initWithNibName:@"WEBViewController"  bundle:nil];

[self  presentModalViewControll er: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:UIControlEventTouchUpIns ide];

[self.view  addSubview:button];

 

 

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 =[UIColorscrollViewTexture dBackgroundColor];
//设置文字的字体
cell.textLabel.font = [UIFontfontWithName:@"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:YESanimated: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 = [theImagestretchableImageWithLeft CapWidth:0topCapHeight:0];
    CGSize theSize = [theAlertframe].size;
      UIGraphicsBeginImageCont ext(theSize);    
    [theImagedrawInRect: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 =UIGraphicsGetImageFromCu rrentImageContext();   
UIGraphicsEndImageContex t();
    theAlert.layer.contents =(id)[theImage CGImage];

 

15.键盘透明：
textField.keyboardAppearance = UIKeyboardAppearanceAler t;

16.状态栏的网络活动风火轮是否旋转：
[UIApplicationsharedApplication].networkActivityIndicator Visible，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)
UIGraphicsBeginImageCont ext(CGSizeMake(200,400)); 

//renderInContext  呈现接受者及其子范围到指定的上下文
[self.view.layerrenderInContext:UIGraphicsGetCurrentCont ext()];
        //返回一个基于当前图形上下文的图片
  UIImage *aImage =UIGraphicsGetImageFromCu rrentImageContext();
    //移除栈顶的基于当前位图的图形上下文
UIGraphicsEndImageContex t();
//以png格式返回指定图片的数据
imageData = UIImagePNGRepresentation (aImage);

 

18.更改cell选中的背景：
      UIView*myview = [[UIView alloc] init];
      myview.frame= CGRectMake(0, 0, 320, 47);
      myview.backgroundColor = [UIColorcolorWithPatternI mage:[UIImageimageNamed:@"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:[UIImageimageNamed:@"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 = [[UIImagealloc]initWithContentsOfFile:imagePath];
              UIImage*newImage= [image transformWidth:80.f height:240.f];
        UIImageView*imageView = [[UIImageView alloc]initWithImage:newImage];
                [newImagerelease];
        [imagerelease];
        [self.viewaddSubview: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:UIControlEventTouchUpIns ide];

 

22.键盘回收：

-（IBAction）textFieldDoneEditing：（id）sender{

[sender resighFirstRespond]；

}

通过点击背景回收键盘：（两个都得添加）

-（IBAction）textFieldDoneEditing：（id）sender{

[sender resighFirstRespond]；

}

-（IBAction）backgroundTapped：（id）sender{

[nameField resignFirstRespond];

[numberField resignFirstRespond];

}