如何从 ALAsset Url 获取视频 url 以在服务器上上传视频？答案

【问题标题】：How to get video url from ALAsset Url for uploading a video on server?如何从 ALAsset Url 获取视频 url 以在服务器上上传视频？
【发布时间】：2014-02-21 07:33:29
【问题描述】：

当使用 ELCImagePickerController 选择视频时，我收到了 assets-library://asset/asset.mp4?id=F0D95698-C982-4723-8959-502CE595E3D1&ext=mp4 url。现在，我必须使用asiDataFormRequest 检索视频名称和媒体网址，以便将此视频上传到服务器上。

当我使用ImagePickerViewController 选择视频时，视频上传工作正常。现在我必须选择多个视频，所以我使用ELCImagePickerController。但它给出了下面给出的视频网址。 assets-library://asset/asset.mp4?id=F0D95698-C982-4723-8959-502CE595E3D1&ext=mp4

如何将此网址转换为 MEdia Url 类型格式。我的主要目标是使用 asihttpdatafromrequest 上传此视频并获得此大小、名称。

【问题讨论】：

标签： ios objective-c alasset elcimagepickercontroller

【解决方案1】：

@KDRocks。此代码正在成功运行以获取具有完整路径的名称。

-(NSString*) videoAssetURLToTempFile:(NSURL*)url
{
    NSString * surl = [url absoluteString];
    NSString * ext = [surl substringFromIndex:[surl rangeOfString:@"ext="].location + 4];
    NSTimeInterval ti = [[NSDate date]timeIntervalSinceReferenceDate];
    NSString * filename = [NSString stringWithFormat: @"%f.%@",ti,ext];
    NSString * tmpfile = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];

    ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
    {
        ALAssetRepresentation * rep = [myasset defaultRepresentation];
        NSUInteger size = [rep size];
        const int bufferSize = 8192;
        NSLog(@"Writing to %@",tmpfile);
        FILE* f = fopen([tmpfile cStringUsingEncoding:1], "wb+");
        if (f == NULL) 
        {
            NSLog(@"Can not create tmp file.");
            return;
        }
        Byte * buffer = (Byte*)malloc(bufferSize);
        int read = 0, offset = 0, written = 0;
        NSError* err;
        if (size != 0) {
        do {
            read = [rep getBytes:buffer
                      fromOffset:offset
                          length:bufferSize
                           error:&err];
            written = fwrite(buffer, sizeof(char), read, f);
            offset += read;
        } while (read != 0);
        }
        fclose(f);
    };
    ALAssetsLibraryAccessFailureBlock failureblock  = ^(NSError *myerror)
    {
        NSLog(@"Can not get asset - %@",[myerror localizedDescription]);

    };
    if(url)
    {
        ALAssetsLibrary* assetslibrary = [[ALAssetsLibrary alloc] init];
        [assetslibrary assetForURL:url
                   resultBlock:resultblock
                  failureBlock:failureblock];
    }
    return tmpfile;
}

【讨论】：