java - 如何检查平板电脑是否插入了SD卡 : Android?

Question

我正在开发一个简单的应用程序，它应该能够从内部存储以及外部存储(可移动卡)(如 Micro SD 卡(当用户插入 SD 卡时))访问文件。

(不是设备附带的内部 sdcard，我知道可以使用Environment.getExternalStorageDirectory())

是否可以查明用户是否已将 SD 卡插入设备？如果是，是否可以获取到该SD卡的路径？

我发现硬编码路径不是一个好的选择，因为不同的设备对用户插入的 sdcard 有不同的路径。

非常感谢任何帮助。谢谢。

Answer 1

(Not the internal sdcard which comes with the device, I know it can be accessed using Environment.getExternalStorageDirectory() )

Android 将可移动存储介质(如 SD 卡)或内部(不可移动)存储视为仅外部存储。

以下是来自 developer.android.com 的表格

Every Android-compatible device supports a shared "external storage" that you can use to save files. This can be a removable storage media (such as an SD card) or an internal (non-removable) storage. Files saved to the external storage are world-readable and can be modified by the user when they enable USB mass storage to transfer files on a computer.

要检查 SDCard 可用性，您可以使用以下代码。

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;
        }
    }

请阅读http://developer.android.com/guide/topics/data/data-storage.html#filesExternal