onRestoreInstanceState不会被调用？

Question

我有一个简单的代码，我想知道在安卓程序执行过程中什么时候调用onRestoreInstanceState？

请帮帮我。

提前谢谢。

我的第一个活动如下

public class AbcActivity extends Activity {
Button b1;
EditText ed1;
Bundle b = new Bundle();

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    Log.v("Tag", "inside oncreate");
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    b1 = (Button) findViewById(R.id.button1);
    ed1 = (EditText) findViewById(R.id.editText1);

    b1.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            Intent intent = new Intent(getApplicationContext(),
                    SecondActivity.class);
            startActivity(intent);
        }
    });
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    Log.v("Tag", "inside onsave instance state");

    outState.putString("key", ed1.getText().toString());
    super.onSaveInstanceState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    Log.v("Tag", "inside on restore instance state");
    super.onRestoreInstanceState(savedInstanceState);

    if (savedInstanceState != null) {
        Log.v("tag", "inside if");
        String str = savedInstanceState.getString("key");
        ed1.setText("" + str);
    }

}

}

我的第二个活动代码如下

public class SecondActivity extends Activity {
Button back;

@Override
protected void onCreate(Bundle savedInstanceState) {
    Log.v("Tag", "inside 2 oncreate");
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second);

    back = (Button) findViewById(R.id.button1);

    back.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            Intent intent = new Intent(getApplicationContext(),
                    AbcActivity.class);
            startActivity(intent);
        }
    });
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    Log.v("Tag", "inside 2 onsave instance state");
    super.onSaveInstanceState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    Log.v("Tag", "inside 2 on restore instance state");
    super.onRestoreInstanceState(savedInstanceState);
}

}

Answer 1

正如文档所述：

当从先前保存的状态重新初始化活动时，在onStart()之后调用此方法...此方法在onStart()和onPostCreate(Bundle)之间调用

当您的Activity在被系统终止或配置更改后重新创建，并且它将其状态保存在onSaveInstanceState(Bundle)中时就是这种情况-在Activity被终止之前总是调用它。