objective-c - 如何从 UIImagePickerController 引用 URL 获取数据？

Question

我正在使用 ELCImagePickerController在我的应用程序中，我不想将选定的 fullScreenImage 保存到我的数组中，因为如果我选择了 40 张 iPad 图像，那就不好了。

我想从 UIImagePickerControllerReferenceURL 而不是 UIImagePickerControllerOriginalImage 从方法 的字典中获取数据 - (void)elcImagePickerController:(ELCImagePickerController *)picker didFinishPickingMediaWithInfo:(NSArray *)信息。

我试过:

NSDictionary *dict = [info objectAtIndex:count];            

NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@",[dict objectForKey:@"UIImagePickerControllerReferenceURL"]]]];//UIImagePNGRepresentation([UIImage imageWithContentsOfFile:[NSString stringWithFormat:@"%@",[dict objectForKey:@"UIImagePickerControllerReferenceURL"]]] );
        NSLog(@"length %d",[data length]);
        imageview.image = [UIImage imageWithData:data];

但是，每次我得到 0 个字节。我已经尝试了论坛中所有可用的答案，但没有用。

谁能回答这个问题？

Answer 1

UIImagePickerControllerReferenceURL 返回 NSURL 对象而不是字符串对象。请将您的代码更改为 -

NSData *data = [NSData dataWithContentsOfURL:[dict objectForKey:@"UIImagePickerControllerReferenceURL"]];
NSLog(@"length %d",[data length]);
imageview.image = [UIImage imageWithData:data];

UIImagePickerControllerReferenceURL 返回 Assets Library 的 NSURL 对象，因此您可以将图像获取为 -

ALAssetsLibrary *assetLibrary=[[ALAssetsLibrary alloc] init];
[assetLibrary assetForURL:[[self.imagedata objectAtIndex:i] valueForKey:UIImagePickerControllerReferenceURL] 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
    [data writeToFile:photoFile atomically:YES];//you can save image later
} failureBlock:^(NSError *err) {
    NSLog(@"Error: %@",[err localizedDescription]);
}];

注意:ALAssetsLibrary 在 iOS 9 中已弃用。