我今天只是学习片段。我按下一个按钮，它隐藏了一个片段。但是，如果我尝试显示片段没有任何反应，为什么？我正在关注本教程，在中间我决定尝试在按下按钮时让片段消失/出现http://www.vogella.com/articles/AndroidFragments/article.html
Button2 片段：
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.button2_fragment,
container, false);
Button button = (Button) view.findViewById(R.id.button2);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ButtonFragment fragment = (ButtonFragment) getFragmentManager()
.findFragmentById(R.id.ButtonFragment);
if (fragment != null && fragment.isInLayout()) {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.hide(fragmentManager.findFragmentById(R.id.ButtonFragment));
transaction.commit();
}
else
{
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.show(fragmentManager.findFragmentById(R.id.ButtonFragment));
transaction.commit();
}
}
});
return view;
}
我在xml中有三个这样的片段：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:background="#123456" >
<fragment
android:id="@+id/ButtonFragment"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:layout_marginTop="?android:attr/actionBarSize"
class="com.example.myfragment.ButtonFragment" ></fragment>
<fragment
android:id="@+id/TimeFragment"
android:layout_width="0dp"
android:layout_weight="2"
android:layout_height="match_parent"
class="com.example.myfragment.TimeFragment" >
<!-- Preview: layout=@layout/details -->
</fragment>
<fragment
android:id="@+id/Button2Fragment"
android:layout_width="0dp"
android:layout_weight="3"
android:layout_height="match_parent"
class="com.example.myfragment.Button2Fragment" >
<!-- Preview: layout=@layout/details -->
</fragment>
</LinearLayout>
代码在我的 button2 片段中，我应该在主要活动中放一些东西吗？
package com.example.myfragment;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
public class MainActivity extends Activity implements ButtonFragment.OnItemSelectedListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
// if the wizard generated an onCreateOptionsMenu you can delete
// it, not needed for this tutorial
@Override
public void onRssItemSelected(String link) {
TimeFragment fragment = (TimeFragment) getFragmentManager()
.findFragmentById(R.id.TimeFragment);
if (fragment != null && fragment.isInLayout()) {
fragment.setText(link);
}
}
}