iOS 使用UIImagePickerController 拍照

    在项目开发的过程中，我们经常会使用的iPhone 或者 iPad 的拍照功能，比如给用户设置头像，一般都会用到拍照功能。我们可以使用UIImagePickerController 类来调用iPhone的摄像头进行拍照或者录视频。iOS 已经为我们封装好了UIImagePickerController ,使用很简单，让我们不用花费很多时间就可以调用拍照功能。使用UIImagePickerController时，需要实现UIImagePickerController协议。

     在xib中添加一个按钮，绑定按钮的响应事件，在响应事件中添加如下代码：

01	UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;

02	//判断是否有摄像头

03	if(![UIImagePickerController isSourceTypeAvailable:sourceType])

04

{

05	sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

06

}

07

08	UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];

09	imagePickerController.delegate = self;   // 设置委托

10	imagePickerController.sourceType = sourceType;

11	imagePickerController.allowsEditing = YES;

12	[self presentViewController:imagePickerController animated:YES completion:nil];  //需要以模态的形式展示

13	[imagePickerController release];

    记得要实现UIImagePickerControllerDelegate 中 的- ( void )imagePickerController:( UIImagePickerController *)picker didFinishPickingMediaWithInfo:( NSDictionary *)info 和  

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker 两个方法，分别时拍照完成的时候调用 和 取消拍照的时候调用。代码如下：

01	#pragma mark -

02	#pragma mark UIImagePickerController Method

03

//完成拍照

04	-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info

05

{

06	[picker dismissViewControllerAnimated:YES completion:^{}];

07	UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];

08	if (image == nil)

09	image = [info objectForKey:UIImagePickerControllerOriginalImage];

10

11	[self performSelector:@selector(saveImage:) withObject:image];

12

13

}

14

//用户取消拍照

15	-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker

16

{

17	[picker dismissViewControllerAnimated:YES completion:nil];

18

}

19

20	//将照片保存到disk上

21	-(void)saveImage:(UIImage *)image

22

{

23

24	NSData *imageData = UIImagePNGRepresentation(image);

25	if(imageData == nil)

26

{

27	imageData = UIImageJPEGRepresentation(image, 1.0);

28

}

29

30	NSDate *date = [NSDate date];

31

32	NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

33	[formatter setDateFormat:@"yyyyMMddHHmmss"];

34	_fileName = [[[formatter stringFromDate:date] stringByAppendingPathExtension:@"png"] retain];

35

36

37	NSURL *saveURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:_fileName];

38

39	[imageData writeToURL:saveURL atomically:YES];

40

41

42

}