ios开发过程中的代码块

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 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.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” ];
    // 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 ];
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 : UIControlEventTouchUpInside ];
[ self . view addSubview :button];
10.2在xib文件中已经创建好Button，通过tag获取按钮

UIButton testButton= (UIButton)[self.view viewWithTag:100];
[testButton addTarget:self action:@selector(test:) forControlEvents:UIControlEventTouchUpInside];
//按钮事件

-(void) test: (id) sender{
UIAlertView *av = [[[UIAlertView alloc] initWithTitle:@”ceshi” message:@”test11111” delegate:nil cancelButtonTitle:@”OK”otherButtonTitles:nil] autorelease];
[av show];
}
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 = [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;
13.隐藏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)];// 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];
15.键盘透明：

textField.keyboardAppearance = UIKeyboardAppearanceAlert;
16.状态栏的网络活动风火轮是否旋转：

[UIApplication sharedApplication].networkActivityIndicatorVisible ， 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)
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 = UIImagePNGR epresentation(aImage);
18.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;:
19.显示图片：

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.能让图片适应框的大小（beta）

NSStringimagePath = [[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];

  1. 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];
22.键盘回收：

1).增加一个button，相应touch down事件，隐藏键盘。这种方法，太山寨了。为了相应一个事件增加一个button太不值得的。

.h

  • (IBAction)dismissKeyBoard:(id)sender;

.m

  • (IBAction)dismissKeyBoard:(id)sender {

    [testText resignFirstResponder];

}
2).第二种方法：在背景图片上添加Tap事件，相应单击处理。这种方法，很好代替了button方式，但是如果UI上没有背景图片，这种方法又回到到第一种山寨的方法行列中。

// 添加带有处理时间的背景图片

UIImageView *backView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)]; 

backView.image = [UIImage imageNamed:@"small3.png"];  



backView.userInteractionEnabled = YES;  

UITapGestureRecognizer *singleTouch = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissKeyboard:)];  

[backView addGestureRecognizer:singleTouch];  



backView.tag = 110;  

[self.view addSubview:backView];

-(void)dismissKeyboard:(id)sender{ 

[text resignFirstResponder];

}
3).在xib文件中，修改xib文件的objects属性，默认是view属性，我们可以修改为UIControl属性，从而是xib文件相应touch down事件。这种方法，缺点就是没有xib就悲剧了。

.h

  • (IBAction)dimissKeyboard:(id)sender;

.m

  • (IBAction)dimissKeyboard:(id)sender {

    [text resignFirstResponder];

}

23、Gif图片的解析

//加载gif

02

03 NSString *filePath = [[NSBundle mainBundle]pathForResource:@”bai3” ofType:@”gif”];

04

05 NSData *data = [NSData dataWithContentsOfFile:filePath];

06

07 CGImageSourceRef gif = CGImageSourceCreateWithData((CFDataRef)data, nil);

08

09 //获取gif的各种属性

10

11 CFDictionaryRef gifprops =(CGImageSourceCopyPropertiesAtIndex(gif,0,NULL));

12

13 NSLog(@”___%@”,gifprops);

14

15

16 NSInteger count =CGImageSourceGetCount(gif);

17

18 NSLog(@”__%d”,count);

19

20

21 CFDictionaryRef gifDic = CFDictionaryGetValue(gifprops, kCGImagePropertyGIFDictionary);

22

23 CFDictionaryRef delay = CFDictionaryGetValue(gifDic, kCGImagePropertyGIFDelayTime);

24

25 NSLog(@”___%@”,delay);

26

27

28 //[gifDic objectForKey:(NSString *)kCGImagePropertyGIFDelayTime];

29

30 // NSNumber * w = CFDictionaryGetValue(gifprops, @”PixelWidth”);

31

32 // NSNumber * h =CFDictionaryGetValue(gifprops, @”PixelHeight”);

33

34 // float totalDuration = delay.doubleValue * count;

35

36 // float pixelWidth = w.intValue;

37

38 // float pixelHeight = h.intValue;

39

40 //将gif解析成UIImage类型对象，并加进images数组中

41

42

43 NSMutableArray *images = [NSMutableArray arrayWithCapacity:count];

44

45 for(int index=0;index<count;index++)

46

47 {

48

49 CGImageRef ref = CGImageSourceCreateImageAtIndex(gif, index, nil);

50

51 UIImage *img = [UIImage imageWithCGImage:ref];

52

53 [images addObject:img];

54

55 CFRelease(ref);

56

57 }

58

59 CFRelease(gifprops);

60

61 CFRelease(gif);

Gif的合成

  • (void)exportAnimatedGif:(CGImageSourceRef )gif :(NSMutableArray *)images

02

03 {

04

05 NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@”animated.gif”];

06

07 CGImageDestinationRef destination = CGImageDestinationCreateWithURL(( CFURLRef)[NSURL fileURLWithPath:path],

08

09 kUTTypeGIF,

10

11 images.count,

12

13 NULL);

14

15 UIImage *image;

16

17 for (int i = 0; i<images.count; i++)

18

19 {

20

21 image = images[i];

22

23 CFDictionaryRef gifprops =(CGImageSourceCopyPropertiesAtIndex(gif,i,NULL));

24

25 CFDictionaryRef gifDic = CFDictionaryGetValue(gifprops, kCGImagePropertyGIFDictionary);

26

27 NSNumber *delay = CFDictionaryGetValue(gifDic, kCGImagePropertyGIFDelayTime);

28

29 NSDictionary gifDelay = [NSDictionary dictionaryWithObject:[NSDictionary dictionaryWithObject:delay forKey:(NSString )kCGImagePropertyGIFDelayTime]

30

31 forKey:(NSString *)kCGImagePropertyGIFDictionary];

32

33

34

35 CGImageDestinationAddImage(destination,image.CGImage, (CFDictionaryRef)gifDelay);

36

37 CGImageDestinationSetProperties(destination, ( CFDictionaryRef)gifprops);

38

39 }

40

41

42

43 // CGImageDestinationSetProperties(destination, ( CFDictionaryRef)gifprops);

44

45 CGImageDestinationFinalize(destination);

46

47 CFRelease(destination);

48

49 NSLog(@”animated GIF file created at %@”, path);

50

51

52 }
24.将一个UIView对象的内容保存为UIImage

  • (UIImage)imageFromView:(UIView)view{

02

03 UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, view.layer.contentsScale);

04

05 [view.layer renderInContext:UIGraphicsGetCurrentContext()];

06

07 UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

08

09 UIGraphicsEndImageContext();

10

11 return image;

12

13 }
注意：生成的图片的scale和view的scale一致，这样才可以保证图片的效果和view显示的完全一致，使用renderInContext方法可以让subviews的内容也显示的图片里。

Title:ios开发过程中的代码块

Author:Lynn Cheng

Created:2016-05-09, 08:48:00

Updated:2016-05-10, 20:58:01

Full URL:http://lynncheng.github.io/2016/05/09/ioscode/

License: "CC BY-NC-SA 4.0" Keep Link & Author if Distribute.

Contents
,