这就是我的工作…(简洁且经过测试)

    ...
    deleteDir(new File(dir_to_be_deleted));
    ...

    // delete directory and contents
    void deleteDir(File file) { 
        if (file.isDirectory())
            for (String child : file.list())
                deleteDir(new File(file, child));
        file.delete();  // delete child file or empty directory
    }

让我告诉你第一件事你不能删除DCIM文件夹，因为它是一个系统文件夹。当你在手机上手动删除它时，它会删除该文件夹的内容，但不会删除DCIM文件夹。您可以通过以下方法删除其内容:

根据评论更新

File dir = new File(Environment.getExternalStorageDirectory()+"Dir_name_here"); 
if (dir.isDirectory()) 
{
    String[] children = dir.list();
    for (int i = 0; i < children.length; i++)
    {
       new File(dir, children[i]).delete();
    }
}

这种方法适用于只包含文件的文件夹，但如果您正在寻找还包含子文件夹的场景，则需要递归

此外，您应该捕获返回的返回值，以确保允许您删除该文件

,包括

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

在你的清单上

void DeleteRecursive(File dir)
{
    Log.d("DeleteRecursive", "DELETEPREVIOUS TOP" + dir.getPath());
    if (dir.isDirectory())
    {
        String[] children = dir.list();
        for (int i = 0; i < children.length; i++)
        {
            File temp = new File(dir, children[i]);
            if (temp.isDirectory())
            {
                Log.d("DeleteRecursive", "Recursive Call" + temp.getPath());
                DeleteRecursive(temp);
            }
            else
            {
                Log.d("DeleteRecursive", "Delete File" + temp.getPath());
                boolean b = temp.delete();
                if (b == false)
                {
                    Log.d("DeleteRecursive", "DELETE FAIL");
                }
            }
        }

    }
    dir.delete();
}

在Kotlin中，您可以使用Kotlin中的deleterecursive()扩展。io包

val someDir = File("/path/to/dir")
someDir.deleteRecursively()

private static void deleteRecursive(File dir)
{
    //Log.d("DeleteRecursive", "DELETEPREVIOUS TOP" + dir.getPath());
    if (dir.isDirectory())
    {
        String[] children = dir.list();
        for (int i = 0; i < children.length; i++)
        {
            File temp = new File(dir, children[i]);
            deleteRecursive(temp);
        }

    }

    if (dir.delete() == false)
    {
        Log.d("DeleteRecursive", "DELETE FAIL");
    }
}

我知道的最安全的代码:

private boolean recursiveRemove(File file) {
    if(file == null  || !file.exists()) {
        return false;
    }

    if(file.isDirectory()) {
        File[] list = file.listFiles();

        if(list != null) {

            for(File item : list) {
                recursiveRemove(item);
            }

        }
    }

    if(file.exists()) {
        file.delete();
    }

    return !file.exists();
}

检查文件是否存在，处理空值，检查目录是否被实际删除