Android：mkdir无法正常工作

Question

我想创建MyFolder目录，但不能做到这一点，尝试过不同的方式，但没有人工作; 在AndroidManifest.xml中我有：

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="my.package" > 
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" /> 
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> 
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> 
    <uses-permission android:name="android.permission.INTERNET" /> 
    <uses-permission android:name="android.permission.RECORD_AUDIO" /> 
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
    <uses-permission android:name="android.permission.WAKE_LOCK" /> 
    <uses-permission android:name="com.android.vending.BILLING" /> 

    <application 
    <!---.....--> 
</manifest> 

静态类：

public static String FILES_DIR = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "MyFolder"; 

代码：

File dir = new File(Constants.FILES_DIR); 
if (!dir.exists()) { 
    dir.mkdir(); 
    Log.i("my tag", "isDirectory + " + dir.toString() + " | " + dir.exists() + " | " + dir.mkdir()); 
    dir = new File(Environment.getExternalStorageDirectory().getAbsolutePath(), "MyFolder"); 
    Log.i("my tag", "isDirectory + " + dir.toString() + " | " + dir.exists() + " | " + dir.mkdir()); 
    dir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC), "MyFolder/"); 
    Log.i("my tag", "isDirectory + " + dir.toString() + " | " + dir.exists() + " | " + dir.mkdir()); 

    Log.i("my tag", "Status + " + Environment.getExternalStorageState()); 
    if (!dir.isDirectory()) return false; 
} 

而且logcat的：

05-09 14:40:15.131 1453-1453/my.package I/my tag﹕ isDirectory + /storage/emulated/0/myFolder | false | false 
05-09 14:40:15.131 1453-1453/my.package I/my tag﹕ isDirectory + /storage/emulated/0/myFolder | false | false 
05-09 14:40:15.136 1453-1453/my.package I/my tag﹕ isDirectory + /storage/emulated/0/Music/myFolder | false | false 
05-09 14:40:15.136 1453-1453/my.package I/my tag﹕ Status + mounted 
05-09 14:40:17.261 1453-1453/my.package I/my tag﹕ isDirectory + /storage/emulated/0/myFolder | false | false 
05-09 14:40:17.261 1453-1453/my.package I/my tag﹕ isDirectory + /storage/emulated/0/myFolder | false | false 
05-09 14:40:17.261 1453-1453/my.package I/my tag﹕ isDirectory + /storage/emulated/0/Music/myFolder | false | false 
05-09 14:40:17.266 1453-1453/my.package I/my tag﹕ Status + mounted 

我也试过mkdirs（）;，用斜线和无，谷歌终于it..and ，我渴望

当我手动箱文件夹，并试图保存文件到路径，我收到权限错误 - 打开失败：EACCES（拒绝）

Answer 1

在我的一个开源项目中，我使用以下类来获取SD卡目录。这只是一个简单的帮助，它应该很容易修改为任何其他SD卡目录或特殊目录。

/** 
* http://developer.android.com/training/basics/data-storage/files.html 
* 
* @param albumName 
* @return 
*/ 
public static File getAlbumStorageDir(String albumName) { 
    // Get the directory for the user's public pictures directory. 
    File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), albumName); 
    if (!file.mkdirs()) { 
     //This is also the case if the directory already existed 
     Log.i("wall-splash", "Directory not created"); 
    } 
    return file; 
} 

在创建一个文件我有以下代码：

File dir = Utils.getAlbumStorageDir("wall-splash") 
//create the file 
File file = new File(dir, fileName); 
if (!file.exists()) { 
    file.createNewFile(); 
} 

---

什么设备要测试吗？它有外部存储吗？任何自定义ROM？

---

尝试重新启动您的设备，以确保以前的尝试没有任何内容被阻止。