有用的小代码

酥油灯厂家酥油灯厂家 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 NSPredicate predicateWithFormat SELF MATCHES emailRegex return emailTest evaluateWithObject 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 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 14 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 酥油灯厂家酥油灯厂家 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 requestreturningResponse nil error nil NSString returnString NSString alloc initWithData returnDataencoding NSUTF8StringEncoding NSLog 3 测试输出 returnString 15 给 imageView 加载图片 UIImage myImage UIImage imageNamed 1 jpg imageView setImage myImage self view addSubview 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 NSDiction ary info 酥油灯厂家酥油灯厂家 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 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 酥油灯厂家酥油灯厂家 label textAlignment UITextAlignmentCenter 自动折行设置 label lineBreakMode UILineBreakModeWordWrap label numberOfLines 0 30 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 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 酥油灯厂家酥油灯厂家 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 my