setRetainInstance不保留实例 [英] setRetainInstance not retaining the instance

问题描述

我试图用setRetainInstance（），但它似乎不是为我工作！ =（。 我简化了问题的最简单的版本：

I'm trying to use setRetainInstance() but it seems not working for me! =(. I simplified the problem to the easiest version:

我有一个TextView和一个按钮的片段。

I have a fragment with a TextView and a Button.

在TextView中的初始文本是我在等待按钮时，pressed文本更改为Hello！

The initial text of the TextView is "I'm waiting" when the button is pressed the text changes to "Hello!"

这是我的code：

的片段：

public class SayHelloFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.say_hello_layout, container);
        final TextView text = (TextView) view.findViewById(R.id.textView1);
        view.findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                text.setText("Hello!");

            }
        });
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        setRetainInstance(true);
    }

}

的活动：

public class MainActivity extends FragmentActivity {

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

}

活动的布局：

<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/say_hello_fragment"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    class="com.example.retaintext.SayHelloFragment" />

片段的布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >


    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="I&apos;m Waiting"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />

</LinearLayout>

但是，当我玩的话，preSS旋钮，改变设备的方向文本变成复位。

But when I play it, press the button and change the device's orientation the text becomes reset.

我在想什么？我该如何解决呢？谢谢！

What am I missing? How can I solve it? Thanks!

推荐答案

您是缺少 onCreateView 再旋转后运行，并再次膨胀时的默认文本的默认视图

You are missing that onCreateView runs after the rotation again and inflates the default view with the default text again.

您需要手动恢复的观点状态，如：

You need to restore the state of your views manually, e.g.:

public class SayHelloFragment extends Fragment {

    private String mText;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.say_hello_layout, container);
        final TextView text = (TextView) view.findViewById(R.id.textView1);
        if (mText != null)
            text.setText(mText);

        view.findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                mText = "Hello!";
                text.setText(mText);
            }
        });
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        setRetainInstance(true);
    }

}

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