我的Fragment用法小例子

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思路：

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在MainActivity的布局文件中，用一个LinearLayout作为一个占位符，点击ButtonA就将fragmentA显示，点击ButtonB就将fragmentB显示。



好了上代码：

首先是acitivity_main.xml布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_horizontal"
android:orientation="vertical" >

<RadioGroup
android:id="@+id/radioGroup"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >

<RadioButton
android:id="@+id/radioButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:button="@null"
android:checked="true"
android:gravity="center_horizontal"
android:text="radioButtonA" />

<RadioButton
android:id="@+id/radioButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:button="@null"
android:gravity="center_horizontal"
android:text="radioButtonB" />

</RadioGroup>

<LinearLayout
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >

</LinearLayout>

</LinearLayout>

fragment_a.xml布局文件：

<?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:gravity="center"
android:orientation="vertical" >

<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:text="A" />

</LinearLayout>

fragment_b.xml布局文件：

<?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:gravity="center"
android:orientation="vertical" >

<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:text="B" />

</LinearLayout>

AFragment.java

package com.example.fragmenttest;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class AFragment extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

return inflater.inflate(R.layout.fragment_a, container, false);
}
}

BFragment.java:

package com.example.fragmenttest;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class BFragment extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

return inflater.inflate(R.layout.fragment_b, container, false);
}

}

MainActivity.java:

package com.example.fragmenttest;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

public class MainActivity extends FragmentActivity implements OnCheckedChangeListener{

AFragment a_fm;
BFragment b_fm;

private RadioGroup group;

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

a_fm = new AFragment();
b_fm = new BFragment();

group = (RadioGroup)findViewById(R.id.radioGroup);
group.setOnCheckedChangeListener(this);

}

@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
switch (checkedId) {
case R.id.radioButton1:
getSupportFragmentManager().beginTransaction().replace(R.id.container, a_fm).commit();
break;

case R.id.radioButton2:
getSupportFragmentManager().beginTransaction().replace(R.id.container, b_fm).commit();
break;
default:
break;
}

}

}