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 kUTTypeMovie表示录像.Editing controlsallowsEditing 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
kUTTypeMoviekUTTypeImage 对应拍照kUTTypeMovie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.
UIImagePickerControllerDelegate在方法主要有两个,
- (void) imagePickerControllerDidCancel: (UIImagePickerController *) picker ; 点击cancel后执行的方法 |
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code:
// 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];
}
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二. 从图片库中选择图片
在选择图片中,ipad 与iphone 会有些不同, ipad展示图片展时,必须要以popover的形式展示,如果想打开一个页面,来modal展示的话,会抛出异常.
这里要设置的属性只要是将
source type改为UIImagePickerControllerSourceTypePhotoLibrary 或UIImagePickerControllerSourceTypeSavedPhotosAlbum,这个是根据自己选择来定.
mediatype的设置与上面的拍照一样.
代码:
如果是iPhone,则代码与上面拍照的一样,只要改下source type就可以了.但如果是ipad,会有所不同,下面的代码就是ipad为例.
在interface中:
@property (strong,nonatomic) UIPopoverController
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
