如何使用 Android 应用程序重命名 sdcard 上的文件？

Question

在我的 Android 应用程序中，我想在运行时重命名文件名。我该怎么做？

这是我的代码：

String[] command = {" mv", "sun moon.jpg"," sun_moon,jpg"};
try
{
    Process process = Runtime.getRuntime().exec(command);
} 
catch (IOException e)
{
    Toast.makeText(this, ""+e, Toast.LENGTH_LONG).show();
}

我也使用了 renameTo(File f) 方法，但它不起作用。

Answer 1

我建议使用File.renameTo() 而不是运行mv 命令，因为我很确定后者不受支持..

你给application permission to write to the SD Card了吗？

你可以通过adding the following to your AndroidManifest.xml：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

如果添加权限后它不起作用，请在尝试重命名文件时检查设备日志是否有错误（使用 adb 命令或在 Eclipse 中的 logcat 视图中） .

访问 SD 卡时，不应硬编码路径，而应使用the Environment.getExternalStorageDirectory() 方法获取目录。

以下代码适用于我：

File sdcard = Environment.getExternalStorageDirectory();
File from = new File(sdcard,"from.txt");
File to = new File(sdcard,"to.txt");
from.renameTo(to);

如果你想检查这个过程，你可以这样做：

boolean renamed = from.renameTo(to);

if (renamed) {
  Log.d("LOG","File renamed...");
}else {
  Log.d("LOG","File not renamed...");
}

Answer 2

你也可以在不指定目录的情况下明确给出完整路径...

File file = new File("Path of file which you want to rename");
File file2 = new File("new name for the file");
    boolean success = file.renameTo(file2);

Answer 3

我尝试添加权限。即使它不起作用，添加 File1.setWritable(true); 使我能够重命名文件。

下面是我的代码sn-p：

if(from.setWritable(true))
    Log.d("InsertFragmentTwo ", "FileName==> Is Writable");
File two = new File(sdcard,""+imageCount+"."+s.substring((s.lastIndexOf(".")+1)));
if (from.renameTo(two)) {
    Log.d("InsertFragmentTwo ", "New FileName==> " + temp);
    imageCount++;
    retrofitImageUpload(temp);
} else
    Log.d("InsertFragmentTwo ", "File Renaming Failed");

Answer 4

public void selectFile() {
    AlertDialog.Builder pictureDialog = new AlertDialog.Builder(this);
    pictureDialog.setTitle("Select Action");
    String[] pictureDialogItems = {
            "Select file from internal storage"};
    pictureDialog.setItems(pictureDialogItems,
            new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    switch (which) {
                        case 0:
                            choosePhotoFromGallary();
                            break;
                    }
                }
            });
    pictureDialog.show();
}
public void choosePhotoFromGallary() {
    Intent galleryIntent = new Intent(Intent.ACTION_PICK,
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

    startActivityForResult(galleryIntent, GALLERY);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode == this.RESULT_CANCELED) {
        return;
    }
    if (requestCode == GALLERY) {
        if (data != null) {
            Uri contentURI = data.getData();
            File dir = Environment.getExternalStorageDirectory();
            if(dir.exists()){
                File from = new File(dir, String.valueOf(GALLERY));
                File to = new File(dir,"filerename.txt");
                if(from.exists())
                    from.renameTo(to);
            }
        }
    }
}