如果存在,如何检查内部和外部存储

Question

我怎么知道android中是否有内部和外部存储实用？有谁知道如何检查内部和外部存储

提前致谢

Answer 1

它已经在android文档中解释过了.

代码取自文档

boolean mExternalStorageAvailable = false;
boolean mExternalStorageWriteable = false;
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;
} 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;
}

Answer 2

我为检查存储状态写了一个小类.也许它对你有用.

更新: 清理代码,删除注释并使类静态.

import android.os.Environment;

public class StorageHelper {

    private static boolean externalStorageReadable, externalStorageWritable;

    public static boolean isExternalStorageReadable() {
        checkStorage();
        return externalStorageReadable;
    }

    public static boolean isExternalStorageWritable() {
        checkStorage();
        return externalStorageWritable;
    }

    public static boolean isExternalStorageReadableAndWritable() {
        checkStorage();
        return externalStorageReadable && externalStorageWritable;
    }

    private static void checkStorage() {
        String state = Environment.getExternalStorageState();
        if (state.equals(Environment.MEDIA_MOUNTED)) {
            externalStorageReadable = externalStorageWritable = true;
        } else if (state.equals(Environment.MEDIA_MOUNTED) || state.equals(Environment.MEDIA_MOUNTED_READ_ONLY)) {
            externalStorageReadable = true;
            externalStorageWritable = false;
        } else {
            externalStorageReadable = externalStorageWritable = false;
        }
    }

}