imagepick返回的asseturl获取图片数据

- (void)imagePickerController:(UIImagePickerController *)picker   didFinishPickingMediaWithInfo:(NSDictionary *)info{    [picker dismissModalViewControllerAnimated:NO];NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];NSLog(@"media type = %@",mediaType);    NSLog(@"media info = %@",info);if([mediaType isEqualToString:@"public.image"])    {NSURL *imgurl = [info objectForKey:UIImagePickerControllerReferenceURL];ALAssetsLibrary *assetLibrary=[[ALAssetsLibrary alloc] init];        [assetLibrary assetForURL:imgurl resultBlock:^(ALAsset *asset)         {             ALAssetRepresentation *rep = [asset defaultRepresentation];             Byte *buffer = (Byte*)malloc(rep.size);             NSUInteger buffered = [rep getBytes:buffer fromOffset:0.0 length:rep.size error:nil];             NSData *data = [NSData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:YES];//this is NSData may be what you want             UIImageView *imageview = [[UIImageView alloc] init];             imageview.frame = CGRectMake(0, 200, 100, 100);             imageview.image = [UIImage imageWithData:data];             imageview.backgroundColor = [UIColor greenColor];             [self.view addSubview:imageview];         }        failureBlock:^(NSError *err) {            NSLog(@"Error: %@",[err localizedDescription]);        }]; }}