IOS 摄像头使用(1)-UIImagePickerController
IOS有两种拍照与拍摄视频的方式
1. 直接使用UIImagePickerController, 这可以提供一个简单便捷的拍照与选择图库里图片的功能.
2.另一种方式就是通过AV Foundation framework,来完全自定义拍照的界面与选择图库的界面.
这里介绍第一种, 如何使用UIImagePickerController.
一.拍照
步骤
1. 定义UIImagePickerController, 启动拍照界面
(1)首先摄像头对于你的应用是必须的,那你应该在项目的Info.plist的Required device capabilities里添加自己要的设备.这里有相关的设备描述.
(2) 要确保你的设备可用,所以在代码中最好先用UIImagePickerController的isSourceTypeAvailable:方面来判断一下,否则如果直接写逻辑,那在设备不可用时,程序会抛异常.
(3) 在拍摄完后,想要能够关掉拍摄界面,那就必须要实现UIImagePickerControllerDelegate
UIImagePickerController 里有几个比较重要的属性.
Source type: 这个参数是用来确定是调用摄像头还是调用图片库.如果是 UIImagePickerControllerSourceTypeCamera 就是调用摄像头,如果是UIImagePickerControllerSourceTypePhotoLibrary 就是调用图片库,如果是UIImagePickerControllerSourceTypeSavedPhotosAlbum 则调用iOS设备中的胶卷相机的图片.
Media types:在拍照时,用来指定是拍静态的图片还是录像.kUTTypeImage 表示静态图片, kUTTypeMovie表示录像.
Editing controls :用来指定是否可编辑.将allowsEditing 属性设置为YES表示可编辑,NO表示不可编辑.
示例代码:(来源于apple官方文档)
- (BOOL) startCameraControllerFromViewController: (UIViewController*) controller usingDelegate: (id <UIImagePickerControllerDelegate, UINavigationControllerDelegate>) delegate { // here, check the device is available or not if (([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera] == NO) || (delegate == nil)|| (controller == nil)) return NO; UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init]; cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera; // Displays a control that allows the user to choose picture or // movie capture, if both are available: cameraUI.mediaTypes = [UIImagePickerControlleravailableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera]; // Hides the controls for moving & scaling pictures, or for // trimming movies. To instead show the controls, use YES. cameraUI.allowsEditing = NO; cameraUI.delegate = delegate; [controller presentModalViewController: cameraUI animated: YES]; returnYES; }
如果只想让摄像头只能摄像,而不能拍照,那应该设置mediaTypes
cameraUI.mediaTypes = [[NSArray alloc] initWithObjects: (NSString *) kUTTypeMovie , nil];
kUTTypeImage 对应拍照
kUTTypeMovie 对应摄像
这要导入MobileCoreServices.framework,然后再
#import <MobileCoreServices/UTCoreTypes.h>
然后就可以在一个触发事件中进行调用.
- (IBAction) showCameraUI {
[self startCameraControllerFromViewController: self
usingDelegate: self];
}
2. 设置delegate
在拍摄完成后,要进行delegate的设置,这样才能够让程序互动起来.
- (void) imagePickerControllerDidCancel: (UIImagePickerController *) picker ; 点击cancel后执行的方法
- (void) imagePickerController: (UIImagePickerController *) picker |
didFinishPickingMediaWithInfo: (NSDictionary *) info; 拍摄完成后要执行的方法 |
// For responding to the user tapping Cancel. - (void) imagePickerControllerDidCancel: (UIImagePickerController *) picker { [[picker parentViewController] dismissModalViewControllerAnimated: YES]; [picker release]; } // For responding to the user accepting a newly-captured picture or movie - (void) imagePickerController: (UIImagePickerController *) picker didFinishPickingMediaWithInfo: (NSDictionary *) info { NSString *mediaType = [info objectForKey: UIImagePickerControllerMediaType]; UIImage *originalImage, *editedImage, *imageToSave; // Handle a still image capture if (CFStringCompare ((CFStringRef) mediaType, kUTTypeImage, 0) == kCFCompareEqualTo) { editedImage = (UIImage *) [info objectForKey: UIImagePickerControllerEditedImage]; originalImage = (UIImage *) [info objectForKey: UIImagePickerControllerOriginalImage]; if (editedImage) { imageToSave = editedImage; } else { imageToSave = originalImage; } // Save the new image (original or edited) to the Camera Roll UIImageWriteToSavedPhotosAlbum (imageToSave, nil, nil , nil); } // Handle a movie capture if (CFStringCompare ((CFStringRef) mediaType, kUTTypeMovie, 0) == kCFCompareEqualTo) { NSString *moviePath = [[info objectForKey: UIImagePickerControllerMediaURL] path]; if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum (moviePath)) { UISaveVideoAtPathToSavedPhotosAlbum ( moviePath, nil, nil, nil); } } [[picker parentViewController] dismissModalViewControllerAnimated: YES]; [picker release]; }
// 这个方法就是在拍摄完成后,将图片或视频,保存到胶卷相机. 我们所需要的东西都保存在info 这个 NSDictionary中 |
@property (strong,nonatomic) UIPopoverController * popoverViewControl;
在implement中:
- (IBAction)takeImage:(id)sender { if ([self.popoverViewControl isPopoverVisible]) { [self.popoverViewControl dismissPopoverAnimated:YES]; }else { if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeSavedPhotosAlbum]) { UIImagePickerController * picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.allowsEditing = NO; picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; // picker.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeSavedPhotosAlbum]; picker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString *) kUTTypeMovie , nil]; self.popoverViewControl = [[UIPopoverControlleralloc] initWithContentViewController:picker]; self.popoverViewControl.delegate = self; CGRect popoverRect = [self.view convertRect:[sender frame] fromView:[sender superview]]; popoverRect.size.width = MIN(popoverRect.size.width, 100); [self.popoverViewControl presentPopoverFromRect:popoverRect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAnyanimated:YES]; } } } - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { self.imageView.image = [info objectForKey:UIImagePickerControllerOriginalImage]; //imageview是自己定义的一个image view 控件,用来显示选中的图片 [self.popoverViewControldismissPopoverAnimated:YES]; }
以上就是UIImagePickerController的大概用法,主要就是自己看了apple的官方文档,然后实践后,记录下来,留用,防止忘了.
对于popover 有一个很好的教程: Using the PopoverView in iPad App Development
