android - 保存和恢复 View 状态android

Question

这个问题在这里已经有了答案:

How to prevent custom views from losing state across screen orientation changes (10 个回答)

关闭 4年前。

我知道 Activity 状态的保存和恢复。但我想做的是保存和恢复 View 的状态。我有一个自定义 View 和两个覆盖的方法:

@Override
protected void onRestoreInstanceState(Parcelable state) {
    if (state instanceof Bundle) {
        Bundle bundle = (Bundle) state;
        currentLeftX = bundle.getInt(CURRENT_LEFT_X_PARAM, 0);
        currentTopY = bundle.getInt(CURRENT_TOP_Y_PARAM, 0);
    }
    super.onRestoreInstanceState(state);
}

@Override
protected Parcelable onSaveInstanceState() {
    super.onSaveInstanceState();
    Bundle bundle = new Bundle();
    bundle.putInt(CURRENT_LEFT_X_PARAM, currentLeftX);
    bundle.putInt(CURRENT_TOP_Y_PARAM, currentTopY);
    return bundle;
}

我希望这可以无缝运行，但遇到了错误:

Caused by: java.lang.IllegalArgumentException: Wrong state class, expecting View State but received class android.os.Bundle instead. This usually happens when two views of different type have the same id in the same hierarchy. This view's id is id/mapViewId. Make sure other views do not use the same id. at android.view.View.onRestoreInstanceState(View.java:6161)

但这个 View 是我 Activity 中唯一的一个。所以，我问:

保存 View 状态的正确方法是什么？

Answer 1

您删除 super.OnSaveInstanceState() 的结果并返回您自己的结果。然后稍后在 OnRestoreInstanceState(Parcelable) 返回您创建的那个。

解决方案在这里:

How to prevent custom views from losing state across screen orientation changes #2