android - onSaveInstanceState 不起作用

Question

当屏幕旋转时...... Toast 什么都不打印!

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    String a  = savedInstanceState.getString("hello");
    Toast.makeText(MainActivity.this, a, Toast.LENGTH_SHORT).show();

}

@Override
public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
    super.onSaveInstanceState(outState, outPersistentState);
    String a = "WTF";
    outState.putString("hello",a);
}

我很好地声明了一切，这个简单的代码中的无赖在哪里!？

Answer 1

我认为自从 Android OS 团队重载了 onSaveInstanceState() 方法以来，您已经陷入了许多开发人员常犯的陷阱。

您正在覆盖错误的方法。你想要的是:

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    String a = "WTF";
    outState.putString("hello",a);
}

就个人而言，我认为 Craig Mautner 应该在每次 Android 开发人员犯此错误时被迫捐款 - source