有用的小代码

常用代码整理：

12.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 = [NSPredicatepredicateWithFormat:@"SELF MATCHES%@",emailRegex];

return[emailTestevaluateWithObject:email];

}

13.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

[imagedrawInRect: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.

returnnewImage;

}

14.亲测可用的图片上传代码

- (IBAction)uploadButton:(id)sender {

UIImage*image = [UIImageimageNamed:@"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 = [[NSMutableURLRequestalloc]init] ;

[requestsetURL:[NSURLURLWithString:urlString]];

[requestsetHTTPMethod:@"POST"];

//

NSString*boundary = [NSStringstringWithString:@"---------------------------14737809831466499882746641449"];

NSString*contentType = [NSStringstringWithFormat:@"multipart/form-data;boundary=%@",boundary];

[requestaddValue:contentTypeforHTTPHeaderField:@"Content-Type"];

//

NSMutableData*body = [NSMutableDatadata];

[bodyappendData:[[NSStringstringWithFormat:@"\r\n--%@\r\n",boundary]dataUsingEncoding:NSUTF8StringEncoding]];

[bodyappendData:[[NSStringstringWithString:@"Content-Disposition:form-data; name=\"userfile\"; filename=\"2.png\"\r\n"]dataUsingEncoding:NSUTF8StringEncoding]]; //上传上去的图片名字

[bodyappendData:[[NSStringstringWithString:@"Content-Type: application/octet-stream\r\n\r\n"]dataUsingEncoding:NSUTF8StringEncoding]];

[bodyappendData:[NSDatadataWithData:imageData]];

[bodyappendData:[[NSStringstringWithFormat:@"\r\n--%@--\r\n",boundary]dataUsingEncoding:NSUTF8StringEncoding]];

[requestsetHTTPBody:body];

// NSLog(@"1-body:%@",body);

NSLog(@"2-request:%@",request);

NSData*returnData = [NSURLConnectionsendSynchronousRequest:requestreturningResponse:nilerror:nil];

NSString*returnString = [[NSStringalloc]initWithData:returnDataencoding:NSUTF8StringEncoding];

NSLog(@"3-测试输出：%@",returnString);

15.给imageView加载图片

UIImage*myImage = [UIImageimageNamed:@"1.jpg"];

[imageViewsetImage:myImage];

[self.viewaddSubview:imageView];

16.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];

}

17.跳到下个View

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

[selfpresentModalViewController:nextWebViewanimated:YES];

//创建一个UIBarButtonItem右边按钮

UIBarButtonItem*rightButton = [[UIBarButtonItemalloc]initWithTitle:@"右边"style:UIBarButtonItemStyleDonetarget:selfaction:@selector(clickRightButton)];

[self.navigationItemsetRightBarButtonItem: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;

30.代码生成button

CGRectframe =CGRectMake(0,400,72.0,37.0);

UIButton*button = [UIButtonbuttonWithType:UIButtonTypeRoundedRect];

button.frame= frame;

[buttonsetTitle:@"新添加的按钮"forState:UIControlStateNormal];

button.backgroundColor= [UIColorclearColor];

button.tag=2000;

[buttonaddTarget:selfaction:@selector(buttonClicked:)forControlEvents:UIControlEventTouchUpInside];

[self.viewaddSubview:button];

31.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;

32.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;

33.———————-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];

33.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];

34.键盘透明
textField.keyboardAppearance = UIKeyboardAppearanceAlert;

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

35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);
36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;

37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];

38.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];

39.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=[[UIButtonalloc]initWithFrame:CGRectMake(0,0,120,120)];

[imgButtonsetBackgroundImage:(UIImage*)[self.imgArrayobjectAtIndex:indexPath.row]forState:UIControlStateNormal];

imgButton.tag=[indexPathrow];

[imgButtonaddTarget:selfaction:@selector(buttonClick:)forControlEvents:UIControlEventTouchUpInside];