用UIImagePickerController選擇、顯示圖片或視頻，主要注意UIImagePickerController幾個屬性的設置
一：UI 顯示樣式，顯示的格式確定
1：sourceType
@property(nonatomic) UIImagePickerControllerSourceType sourceType
enum {
UIImagePickerControllerSourceTypePhotoLibrary,
UIImagePickerControllerSourceTypeCamera,
UIImagePickerControllerSourceTypeSavedPhotosAlbum
};
typedef NSUInteger UIImagePickerControllerSourceType;
sourceType用來確定用戶界面顯示的樣式：
共三種格式（模擬器上的效果圖）
UIImagePickerControllerSourceTypePhotoLibrary,
UIImagePickerControllerSourceTypeCamera,
UIImagePickerControllerSourceTypeSavedPhotosAlbum
為了區分是否支持視頻格式，一般要用到下面這個函數，以便確定mediaTypes。
+ (BOOL)isSourceTypeAvailable:(UIImagePickerControllerSourceType)sourceType
2: mediaTypes
@property(nonatomic,copy) NSArray *mediaTypes
mediaTypes用來確定再picker里顯示那些類型的多媒體文件，圖片？視頻？
+ (NSArray *)availableMediaTypesForSourceType:(UIImagePickerControllerSourceType)sourceType
二：選取動作處理
UIImagePickerControllerDelegate
通過代理來完成用戶在選中圖片，或者choose視頻時的處理方式：
共有三個可選的代理方法
– imagePickerController:didFinishPickingMediaWithInfo:
– imagePickerControllerDidCancel:
– imagePickerController:didFinishPickingImage:editingInfo: Deprecated in iPhone OS 3.0
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
info中包括選取的照片，視頻的主要信息
NSString *const UIImagePickerControllerMediaType; 選取的類型 public.image public.movie
NSString *const UIImagePickerControllerOriginalImage; 修改前的UIImage object.
NSString *const UIImagePickerControllerEditedImage; 修改后的UIImage object.
NSString *const UIImagePickerControllerCropRect; 原始圖片的尺寸NSValue object containing a CGRect data type
NSString *const UIImagePickerControllerMediaURL; 視頻在文件系統中 的 NSURL地址
保存視頻主要時通過獲取其NSURL 然后轉換成NSData
實例代碼如下：
- (void) pickImage: (id) sender
{
UIImagePickerController *ipc = [[UIImagePickerController alloc] init];
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
ipc.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
ipc.mediaTypes =[UIImagePickerController availableMediaTypesForSourceType:ipc.sourceType];
}
ipc.delegate = self;
ipc.allowsImageEditing = NO;
[self presentModalViewController:ipc animated:YES];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
if ([mediaType isEqualToString:@"public.image"]){
//UIImage *selectedImage = [info objectForKey:UIImagePickerControllerOriginalImage];
UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSLog(@"found an image");
[UIImageJPEGRepresentation(image, 1.0f) writeToFile:[self findUniqueSavePath] atomically:YES];
SETIMAGE(image);
CFShow([[NSFileManager defaultManager] directoryContentsAtPath:[NSHomeDirectory() stringByAppendingString:@"/Documents"]]);
}
else if ([mediaType isEqualToString:@"public.movie"]){
NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];
NSLog(@"found a video");
NSData *webData = [NSData dataWithContentsOfURL:videoURL];
//NSData *video = [[NSString alloc] initWithContentsOfURL:videoURL];
[webData writeToFile:[self findUniqueMoviePath] atomically:YES];
CFShow([[NSFileManager defaultManager] directoryContentsAtPath:[NSHomeDirectory() stringByAppendingString:@"/Documents"]]);
//NSLog(videoURL);
}
[picker dismissModalViewControllerAnimated:YES];
}