Question

我想使用QLPreviewController来显示Photo Stream中的ALAssets QLPreviewController需要NSURL才能显示项目

当它是文件URL时，这很有用的/ var /移动/应用/ 5374 ...... 9E0 /文档/ image33.png

我有ALAsset 但是使用[[asset defaultRepresentation] url]给我一个NSURL类型
assets-library：//asset/asset.JPG？id = 00000000-0000-0000-0000-000000000075＆amp; ext = JPG

但这不显示QLPreviewController只是一直显示加载??

有什么想法吗？提前致谢

Answer 1

也许不是最快最有效的方法，但它解决了这个问题。请使用NSFilemanager代替NSTemporaryDirectory，如文档所述:-)确保链接到ImageIO.framework

    #import <ImageIO/ImageIO.h>

    ....
    NSURL *outURLToUseWithQLPreviewController = nil;

    ALAsset *myAsset = ... // received somehow
    ALAssetRepresentation *represent = myAsset.defaultRepresentation;
    CGImageRef representFullScreen = represent.fullScreenImage;

    NSString *tempDir = NSTemporaryDirectory();
    NSString *imagePath = [tempDir stringByAppendingPathComponent:represent.filename];
    NSURL *tempURL = [NSURL fileURLWithPath:imagePath];

    CGImageDestinationRef destination = CGImageDestinationCreateWithURL((__bridge CFURLRef)(tempURL), (__bridge CFStringRef)(represent.UTI), 1, NULL);
    CGImageDestinationAddImage(destination, representFullScreen, nil);
    if ( CGImageDestinationFinalize(destination) ) {
        outURLToUseWithQLPreviewController = tempURL;
    }
    return outURLToUseWithQLPreviewController;

使用QLPreviewController显示ALAsset

1 个答案: