设置权限后提示"SDcard mounted RO"

我在 Manifest 文件中添加<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />。当我运行下面的代码时，提示"SDcard mounted RO"。哪里出错呢？

if(!extState.equals(Environment.MEDIA_MOUNTED)) {
        Log.d(Tag.getTag(this),
                ("SDcard not mounted"));
    }
    else if (!extState.equals(Environment.MEDIA_MOUNTED_READ_ONLY)) {
        Log.d(Tag.getTag(this),
                ("SDcard mounted RO"));
    }
    else {
        Log.d(Tag.getTag(this),
                ("SDcard mounted RW"));
    }

!extState.equals(Environment.MEDIA_MOUNTED_READ_ONLY)

不为RO时提示RO。错在这里，去掉“!”

你代码的逻辑好像错了

if(!extState.equals(Environment.MEDIA_MOUNTED)) {
    Log.d(Tag.getTag(this),
            ("SDcard not mounted"));
}
else ...

要改为：

if(extState.equals(Environment.MEDIA_MOUNTED)) {
    Log.d(Tag.getTag(this),
            ("SDcard mounted RW"));

}
else if (extState.equals(Environment.MEDIA_MOUNTED_READ_ONLY)) {
    Log.d(Tag.getTag(this),
            ("SDcard mounted RO"));
}
else {
    Log.d(Tag.getTag(this),
            ("SDcard not mounted"));
}