android - onSaveInstanceState 不能保存静态变量？

Question

考虑以下代码，它将静态变量:mMyArray 保存在 onSaveInstanceState 中，并在 onRestoreInstanceState 中恢复它，但是我发现它根本无法保存 int 数组。我试过原始类型值(int)，它可以保存/恢复原始类型值。

public class StaticVarActivity extends Activity {

    private static final String TAG = "StaticVarActivity";

    private static int[] mMyArray = { 1, 1 };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Log.d(TAG, "Setting values to 2 in onCreate");
        mMyArray[0] = 2;
        mMyArray[1] = 2;

        findViewById(R.id.btn).setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                Log.d(TAG, "Setting values to 3 in onClick");
                mMyArray[0] = 3;
                mMyArray[1] = 3;
            }
        });
    }

    /* (non-Javadoc)
     * @see android.app.Activity#onRestoreInstanceState(android.os.Bundle)
     */
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);

        Log.d(TAG,"onRestoreInstanceState 1:"+mMyArray[0]+","+mMyArray[1]);
        mMyArray = savedInstanceState.getIntArray("key");
        Log.d(TAG,"onRestoreInstanceState 2:"+mMyArray[0]+","+mMyArray[1]);

    }

    /* (non-Javadoc)
     * @see android.app.Activity#onSaveInstanceState(android.os.Bundle)
     */
    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        Log.d(TAG,"onSaveInstanceState 1:"+mMyArray[0]+","+mMyArray[1]);
        //int[] sss = new int[]{mMyArray[0],mMyArray[1]};
        //outState.putIntArray("key", sss);
        outState.putIntArray("key", mMyArray);
        Log.d(TAG,"onSaveInstanceState 2:"+mMyArray[0]+","+mMyArray[1]);
    }
}

日志:

---

04-14 15:16:00.633: DEBUG/StaticVarActivity(7251): 在 onCreate 中将值设置为 204-14 15:16:19.843: DEBUG/StaticVarActivity(7251): 在 onClick 中将值设置为 3

//改变配置，例如改变方向

04-14 15:16:23.893: DEBUG/StaticVarActivity(7251): onSaveInstanceState 1:3,304-14 15:16:23.893: DEBUG/StaticVarActivity(7251): onSaveInstanceState 2:3,304-14 15:16:24.073: DEBUG/StaticVarActivity(7251): 在 onCreate 中将值设置为 204-14 15:16:24.073: DEBUG/StaticVarActivity(7251): onRestoreInstanceState 1:2,204-14 15:16:24.073: DEBUG/StaticVarActivity(7251): onRestoreInstanceState 2:2,2

---

如果我改为:

private int[] mMyArray = { 1, 1 };

日志将是:

---

04-14 15:18:29.183:DEBUG/StaticVarActivity(7355):在 onCreate 中将值设置为 204-14 15:18:32.123: DEBUG/StaticVarActivity(7355): 在 onClick 中将值设置为 3

//改变配置，例如改变方向

04-14 15:18:33.353: DEBUG/StaticVarActivity(7355): onSaveInstanceState 1:3,304-14 15:18:33.353: DEBUG/StaticVarActivity(7355): onSaveInstanceState 2:3,304-14 15:18:33.373: DEBUG/StaticVarActivity(7355): 在 onCreate 中将值设置为 204-14 15:18:33.393: DEBUG/StaticVarActivity(7355): onRestoreInstanceState 1:2,204-14 15:18:33.393: DEBUG/StaticVarActivity(7355): onRestoreInstanceState 2:3,3

---

我知道它不需要保存静态变量，但为什么会这样？

Answer 1

据我所知，您不能将 static int[] 替换为另一个 int[]。您可以将 static int[] 的成员替换为其他 int 值。