无法在 Android 上写入外部存储 [英] Can't write to external storage on Android

问题描述

我看到很多其他人在问同样的问题，但发布的解决方案都没有帮助我.

I see a bunch of other people asking this same question, but none of the solutions posted helped me.

我正在尝试将一个(二进制)文件从我的 Android 应用程序写入外部存储.我将 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 放入我的清单中，但我仍然无法创建任何文件.我用来创建文件的代码是

I'm trying to write a (binary) file to external storage from my Android app. I put <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> into my manifest, but I still can't manage to create any files. The code I'm using to create files is

File folder = new File(Environment.getExternalStorageDirectory(), SAVE_DIRECTORY);
File toWrite = new File(folder, "save.bin");
if(!toWrite.exists()){
    try {
        if(!folder.mkdirs())
            Log.e("Save", "Failed to create directories for save file!");
        toWrite.createNewFile();
     } catch (IOException e) {
         Log.e("Save", "Failed to create save file! " + e.getMessage());
     }
 }

调用 mkdirs() 失败，createNewFile() 抛出 IOException(ENOENT，因为目录不存在)

The call to mkdirs() fails, and the createNewFile() throws the IOException (ENOENT, because the directory doesn't exist)

有人知道怎么回事吗?我什至尝试重新启动我的设备.我在 Nexus 7 上的 API 级别为 8(如果有什么不同的话).

Anybody know what's up? I've even tried rebooting my device. I'm on API level 8 on a Nexus 7, if it makes any difference.

推荐答案

首先你应该检查 ExternalStorageState

public static boolean isSDCARDAvailable(){
   return Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);
}

如果这个方法isSDCARDAvailable返回true，那么使用你的代码

if this method isSDCARDAvailable return true, then use your code

添加权限:

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

这篇关于无法在 Android 上写入外部存储的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！