iPhone:从文档目录文件夹复制或移动文件 [英] iphone: copy or move file from document directory folder

问题描述

这是我的代码.

NSArray *pathSong = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *toPath = [[pathSong objectAtIndex:0] stringByAppendingPathComponent:@"Songs"];
    NSString *fromPath=[[pathSong objectAtIndex:0] stringByAppendingPathComponent:@"abc"];
    NSString *strdestination = [fromPath stringByAppendingPathComponent:@"sg.mp3"];
    NSError *Error;
    if([[NSFileManager defaultManager]fileExistsAtPath:strdestination]){
        if([[NSFileManager defaultManager]copyItemAtPath:strdestination toPath:toPath error:&Error]==NO){
            UIAlertView *Alert=[[UIAlertView alloc]initWithTitle:@"copy" message:[NSString stringWithFormat:@"%@",Error] delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
            [Alert show];
        }
        else{
            UIAlertView *Alert=[[UIAlertView alloc]initWithTitle:@"Not copy" message:[NSString stringWithFormat:@"%@",Error] delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
            [Alert show];
        }
    }

我收到错误徽标:

Error Domain = NSCocoaErrorDominCode = 516无法执行该操作 完成.(可可箭头516.)" userInfo = 0x681abf0

Error Domain=NSCocoaErrorDominCode=516 "The operation couldn't be completed .(Cocoa arrow 516.)" userInfo=0x681abf0

NSUnderlyingError = 0x681b920该操作无法完成 .文件存在"

NSUnderlyingError =0x681b920 "The operation couldn't be completed .File exists"

abc文件夹中没有歌曲名称"sg.mp3"，但我仍然收到文件存在错误.我不知道我在哪里弄错了?

abc folder there is no song name "sg.mp3" but I'm still getting the file exists error. I don't know where I did mistake?

推荐答案

您的代码中存在两个问题:

There is two issues in your code:

1. 如果文件已经存在，您需要将其删除
2. 您需要为目标文件指定一个名称，这意味着如果您使用类似的话:

NSString *toPath = [[pathSong objectAtIndex:0] stringByAppendingPathComponent:@"Songs"];

和

[[NSFileManager defaultManager]copyItemAtPath:strdestination toPath:toPath error:&Error];

然后，如果发生复制，它将把Sg.mp3文件复制为没有任何类型的歌曲.

Then if copy occurs, it will copy the Sg.mp3 file as Songs without any type.

所以您需要这样写:

NSArray *pathSong = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *tempPath = [[pathSong objectAtIndex:0] stringByAppendingPathComponent:@"Songs"];
NSString *toPath = [tempPath stringByAppendingPathComponent:@"yourFileName.mp3"];
NSString *fromPath = [[pathSong objectAtIndex:0] stringByAppendingPathComponent:@"abc"];
NSString *strdestination = [fromPath stringByAppendingPathComponent:@"sg.mp3"];
NSError *Error = nil;

if([[NSFileManager defaultManager]fileExistsAtPath:strdestination])
{

  if([[NSFileManager defaultManager]copyItemAtPath:strdestination toPath:toPath error:&Error]==NO)
   {
       UIAlertView *Alert=[[UIAlertView alloc]initWithTitle:@"copy" message:[NSString stringWithFormat:@"%@",Error] delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
       [Alert show];
   }
   else
   {
      [fileManager removeItemAtPath:strdestination error:NULL];
       UIAlertView *Alert=[[UIAlertView alloc]initWithTitle:@"Not copy" message:[NSString stringWithFormat:@"%@",Error] delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
       [Alert show];
   }
}

此代码将删除目标位置的文件，然后将sg.mp3从abc文件夹复制到名称为yourFileName.mp3

This code will remove the file if exist at destination and then copy the sg.mp3 from abc folder to Songs folder with the name yourFileName.mp3

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