該類繼承自UINavigationController類
步驟：
檢查媒體來源模式是否可用
檢查該來源模式下所支持的媒體類型
創建圖像選取控制器，設置其屬性并顯示
在委托協議方法中處理
1.檢查媒體來源
調用UIImagePickerController類的靜態方法isSourceTypeAvailable來檢查
sourceType是一個UIImagePickerControllerSourceType類型的枚舉值，它表示圖像選取控制器的3種不同的媒體來源模式
UIImagePickerControllerSourceTypePhotoLibrary:照片庫模式。圖像選取控制器以該模式顯示時會瀏覽系統照片庫的根目錄。
UIImagePickerControllerSourceTypeCamera:相機模式，圖像選取控制器以該模式顯示時可以進行拍照或攝像。
UIImagePickerControllerSourceTypeSavedPhotosAlbum:相機膠卷模式，圖像選取控制器以該模式顯示時會瀏覽相機膠卷目錄。
如果設備支持指定的媒體來源模式，則isSourceTypeAvailable:方法返回YES，否則返回NO。
2.檢查支持的媒體類型
調用UIImagePickerController類的另一個靜態方法 availableMediaTypesForSourceType:
返回的是字符串數組，kUTTypeImage表示靜態圖片，kUTTypeMovie表示視頻。這兩個字符串常量定義在MobileCoreServices框架中。
參數info是一個字典，包含媒體類型，拍照的原始圖片，編輯后的圖片，或是攝像的視頻文件的URL等。
- (IBAction)takePictureButtonClick:(id)sender{
//檢查相機模式是否可用
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
NSLog(@"sorry, no camera or camera is unavailable.");
return;
}
//獲得相機模式下支持的媒體類型
NSArray* availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
BOOL canTakePicture = NO;
for (NSString* mediaType in availableMediaTypes) {
if ([mediaType isEqualToString:(NSString*)kUTTypeImage]) {
//支持拍照
canTakePicture = YES;
break;
}
}
//檢查是否支持拍照
if (!canTakePicture) {
NSLog(@"sorry, taking picture is not supported.");
return;
}
//創建圖像選取控制器
UIImagePickerController* imagePickerController = [[UIImagePickerController alloc] init];
//設置圖像選取控制器的來源模式為相機模式
imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
//設置圖像選取控制器的類型為靜態圖像
imagePickerController.mediaTypes = [[[NSArray alloc] initWithObjects:(NSString*)kUTTypeImage, nil] autorelease];
//允許用戶進行編輯
imagePickerController.allowsEditing = YES;
//設置委托對象
imagePickerController.delegate = self;
//以模視圖控制器的形式顯示
[self presentModalViewController:imagePickerController animated:YES];
[imagePickerController release];
}
- (IBAction)captureVideoButtonClick:(id)sender{
//檢查相機模式是否可用
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
NSLog(@"sorry, no camera or camera is unavailable!!!");
return;
}
//獲得相機模式下支持的媒體類型
NSArray* availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
BOOL canTakeVideo = NO;
for (NSString* mediaType in availableMediaTypes) {
if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
//支持攝像
canTakeVideo = YES;
break;
}
}
//檢查是否支持攝像
if (!canTakeVideo) {
NSLog(@"sorry, capturing video is not supported.!!!");
return;
}
//創建圖像選取控制器
UIImagePickerController* imagePickerController = [[UIImagePickerController alloc] init];
//設置圖像選取控制器的來源模式為相機模式
imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
//設置圖像選取控制器的類型為動態圖像
imagePickerController.mediaTypes = [[[NSArray alloc] initWithObjects:(NSString*)kUTTypeMovie, nil] autorelease];
//設置攝像圖像品質
imagePickerController.videoQuality = UIImagePickerControllerQualityTypeHigh;
//設置最長攝像時間
imagePickerController.videoMaximumDuration = 30;
//允許用戶進行編輯
imagePickerController.allowsEditing = YES;
//設置委托對象
imagePickerController.delegate = self;
//以模式視圖控制器的形式顯示
[self presentModalViewController:imagePickerController animated:YES];
[imagePickerController release];
}
- (void)image:(UIImage*)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo{
if (!error) {
NSLog(@"picture saved with no error.");
}
else
{
NSLog(@"error occured while saving the picture%@", error);
}
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
//打印出字典中的內容
NSLog(@"get the media info: %@", info);
//獲取媒體類型
NSString* mediaType = [info objectForKey:UIImagePickerControllerMediaType];
//判斷是靜態圖像還是視頻
if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
//獲取用戶編輯之后的圖像
UIImage* editedImage = [info objectForKey:UIImagePickerControllerEditedImage];
//將該圖像保存到媒體庫中
UIImageWriteToSavedPhotosAlbum(editedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])
{
//獲取視頻文件的url
NSURL* mediaURL = [info objectForKey:UIImagePickerControllerMediaURL];
//創建ALAssetsLibrary對象并將視頻保存到媒體庫
ALAssetsLibrary* assetsLibrary = [[ALAssetsLibrary alloc] init];
[assetsLibrary writeVideoAtPathToSavedPhotosAlbum:mediaURL completionBlock:^(NSURL *assetURL, NSError *error) {
if (!error) {
NSLog(@"captured video saved with no error.");
}else
{
NSLog(@"error occured while saving the video:%@", error);
}
}];
[assetsLibrary release];
}
[picker dismissModalViewControllerAnimated:YES];
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
[picker dismissModalViewControllerAnimated:YES];
}
