如何在代码中检查外部存储设备是否为只读答案

【问题标题】：how to check in code whether an external storage device is read only如何在代码中检查外部存储设备是否为只读
【发布时间】：2012-11-23 05:38:47
【问题描述】：

在我的 android 应用程序中，我将一些文件写入 SD 卡。但是有一个条件，如果 SD 卡是只读的然后我必须相应地更改屏幕设置。如果 SD 卡是只读的，我如何在我的代码中检查它？

【问题讨论】：

标签： android sd-card readonly

【解决方案1】：

尝试将Environment.MEDIA_MOUNTED_READ_ONLY 用作：

String status = Environment.getExternalStorageState();
if (status.equalsIgnoreCase(Environment.MEDIA_MOUNTED)) {
    Toast.makeText(Activity.this, "SD MEDIA_MOUNTED", Toast.LENGTH_LONG).show();

} else if (status.equalsIgnoreCase(Environment.MEDIA_MOUNTED_READ_ONLY)) {
    Toast.makeText(Activity.this, "MEDIA_MOUNTED_READ_ONLY", 
          Toast.LENGTH_LONG).show();
}

【讨论】：

【解决方案2】：

还有更完整的答案...

String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
    // We can read and write the media
    mExternalStorageAvailable = mExternalStorageWriteable = true;

}
else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
    // We can only read the media
    mExternalStorageAvailable = true;
    mExternalStorageWriteable = false;
//    check_folder();
} else {
    // Something else is wrong. It may be one of many other states, but all we need
    //  to know is we can neither read nor write
    mExternalStorageAvailable = mExternalStorageWriteable = false;

}

【讨论】：