ios - 将视频从库复制到 Documents 文档目录

Question

我正在 ios 应用程序中构建任务，我想将视频从库复制到本地应用程序文档目录。 我已经成功地从数组中的库中获取了 ALAssest 列表。 现在，当我尝试将任何视频从 ALAssest url 复制到我们的文件时，我总是收到以下错误

" Error Domain=NSCocoaErrorDomain Code=262 "The operation couldn’t be completed. (Cocoa error 262.)" UserInfo=0x157d4a70 {NSURL=assets-library://asset/asset.m4v?id=B01C37C9-8C8C-4963-BAC8-EE0356C079DD&ext=m4v"

我在文档目录下做了一个文件夹用来存放视频

NSString *path;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"AppVideo"];
NSError *error=nil;
if (![[NSFileManager defaultManager] fileExistsAtPath:filePath])    //Does directory already exist?
{
    if (![[NSFileManager defaultManager] createDirectoryAtPath:filePath
                                   withIntermediateDirectories:NO
                                                    attributes:nil
                                                         error:&error])
    {
        NSLog(@"Create directory error: %@", error);
    }
    NSLog(@"pathToPatientPhotoFolder filePath=%@",filePath);
}

下面是复制数据的代码

NSError *error=nil;

NSString *path;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
path = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"AppVideo"];
path = [path stringByAppendingPathComponent:@"myvideo.mp4"];
NSURL * url=nil;
 url=[[[self.dataContainer objectAtIndex:selected] defaultRepresentation] url];
[[NSFileManager defaultManager] copyItemAtURL:url toURL:[NSURL URLWithString:path] error:&error];

if(error)
    NSLog(@"Writing Error=%@",error.description);
else
    NSLog(@"writing has done without error");
`

我也尝试将 ALAssest url 的 NSData 写入文件但是当我用 MPMoviePlayerViewController 播放它时它只显示黑屏

 ALAssetRepresentation *rep = [[self.dataContainer objectAtIndex:selected] defaultRepresentation];

Byte *buffer = (Byte*)malloc(rep.size);
NSUInteger buffered = [rep getBytes:buffer fromOffset:0.0 length:rep.size error:nil];
NSData *FileData = [NSData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:NO];


[[NSFileManager defaultManager] createFileAtPath:path
                                        contents:FileData
                                      attributes:nil];

但没有找到任何解决方案。

Answer 1

真正的问题更深一点。你应该调用

[NSURL fileURLWithPath:<# string path #>]

代替

[NSURL URLWithString:path]

如果您使用的是文件系统，则必须使用特定的 URL。