iOS开发常用代码片段整理

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 contextUIGraphicsBeginImageContext(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 contextUIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();// End the contextUIGraphicsEndImageContext();// 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 urlNSString *urlString = @"http://192.168.1.113:8090/text/UploadServlet";//服务器地址// setting up the request object nowNSMutableURLRequest *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];//创建一个UIBarButtonItem右边按钮UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithTitle:@"右边" style:UIBarButtonItemStyleDone target:self action:@selector(clickRightButton)];[self.navigationItem setRightBarButtonItem: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;

7.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];

8.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;

9.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;10.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];

11.更改AlertView背景

UIAlertView *theAlert = [[[UIAlertViewalloc] initWithTitle:@"Atention"message: @"I'm a Chinese!"delegate:nilcancelButtonTitle:@"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];

12.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。

13.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);

14.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;

15.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];

16.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];

17.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];