android - 如何高效检测SD卡是否存在且可写？

Question

我正在使用以下代码来检查 Sd 卡是否存在并且可写。但是当我在模拟器的 Sd 卡上下文中使用该代码时，它表明模拟器中不存在 Sd 卡，但实际上，文件资源管理器显示相应模拟器的 Sd 卡的内容。这是代码:

static public boolean hasStorage(boolean requireWriteAccess) {
    //TODO: After fix the bug,  add "if (VERBOSE)" before logging errors.
    String state = Environment.getExternalStorageState();
    System.out.println("storage state is " + state);

    if (Environment.MEDIA_MOUNTED.equals(state)) {
        if (requireWriteAccess) {
            boolean writable = checkFsWritable();
            System.out.println("storage writable  is " + writable );
            return writable;
        } else {
            return true;
        }
    } else if (!requireWriteAccess && Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
        return true;
    }
    return false;
}

此代码显示未安装 SD 卡，但文件资源管理器显示不同的图片。请帮助我。在此先感谢。

Answer 1

这项工作将检查挂载和是否可读。

private boolean isExternalStorageAvailable() {

        String state = Environment.getExternalStorageState();
        boolean mExternalStorageAvailable = false;
        boolean mExternalStorageWriteable = false;

        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;
        } 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;
        }

        if (mExternalStorageAvailable == true
                && mExternalStorageWriteable == true) {
            return true;
        } else {
            return false;
        }
    }