相册iosbuttonimageuiviewpathUIImagePickerController概述：UIImagePickerController 类是获取选择图片和视频的用户接口。我们可以用这个controller选择我们所需要的图片和视频。对于这个类来说比较特殊，我们不能够任意定制，也不可以继承生成子类。我们在用UIImagePickerController类的时候，只需要调用用代码实现其在什么位置显示和开始，当然我们之后可以选择所需的图片和影片，或者也可以不选择点击取消即可。但是在我们调用接口之前，我们需要确认：一：当前设备是否支持使用UIImagePickerController，这个时候我们需要调用isSourceTypeAvailable:方法判断。二：查看符合的媒体类型（图片或者视频），这个时候我们调用availableMediaTypesForSourceType: 方法判断。同时使用UIImagePickerController时，我们需要UIImagePickerControllerDelegate协议代理实现一些特定时间特定的动作。在调用摄像头的时候我们可以选择使用闪光灯，但是默认条件下对视频有10分钟的限制，需要用videoMaximumDuration属性更改默认时间，三：之后我们设定界面媒体的属性  1：sourceType  //从哪选取媒体enum {UIImagePickerControllerSourceTypePhotoLibrary,UIImagePickerControllerSourceTypeCamera,UIImagePickerControllerSourceTypeSavedPhotosAlbum};typedef NSUInteger UIImagePickerControllerSourceType;2:   mediaTypesmediaTypes用来确定再picker里显示那些类型的多媒体文件，图片？视频？+ (NSArray *)availableMediaTypesForSourceType:(UIImagePickerControllerSourceType)sourceType一共有三个可选的代理方法UIImagePickerControllerDelegate – imagePickerController:didFinishPickingMediaWithInfo:  – imagePickerControllerDidCancel:  – imagePickerController:didFinishPickingImage:editingInfo: -(void) pick{[imagePicker takePicture];}- (IBAction)press:(id)sender {imagePicker = ［UIImagePickerController alloc] init];imagePicker.delegate = self;imagePicker.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;imagePicker.showsCameraControls = NO;UIView* view = ［UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];view.backgroundColor = [UIColor redColor];UIButton* button = ［UIButton alloc] initWithFrame:CGRectMake(0, 0, 40, 40)];button.backgroundColor = [UIColor blueColor];[button addTarget:self action:@selector(pick) forControlEvents:UIControlEventTouchUpInside];[view addSubview:button];CGRect newFrame = CGRectMake(0.0,436,320,44);view.frame = newFrame;imagePicker.cameraOverlayView = view;[self presentModalViewController:imagePicker animated:YES];}-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {if (［info objectForKey:UIImagePickerControllerMediaType] isEqualToString:(NSString*)kUTTypeImage]) {UIImage* image = [info objectForKey:UIImagePickerControllerOriginalImage];UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);} else if (［info objectForKey:UIImagePickerControllerMediaType] isEqualToString:(NSString*)kUTTypeMovie]) {NSString* path = ［info objectForKey:UIImagePickerControllerMediaURL] path];   UISaveVideoAtPathToSavedPhotosAlbum(path, self, @selector(video:didFinishSavingWithError:contextInfo:), nil); }[picker dismissModalViewControllerAnimated:YES];}-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {[picker dismissModalViewControllerAnimated:YES];}