#Fragment 是3.0平板才引入进来的，3.0之后就加入了Fragment。原来是一个屏幕就是一个Activity，
>片段,碎片
1. 定义某一个片段的界面 继承Fragment类 public class BlueToothFragment extends Fragment {} 2. 重写Fragment里面的方法 显示Fragment的ui,把布局文件转化成view对象 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.blue_tooth_layout, null); } 3. 获取Fragment管理器 fm = getFragmentManager(); 4. 动态的修改界面 f1 = new BlueToothFragment();//先把要显示的f1new出来 FragmentTransaction ft = fm.beginTransaction();//开启事务 ft.replace(R.id.fl_container, f1); ft.commit();//保证了 要么同时成功,要么同时失败
主页面：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" 垂直排列 tools:context=".MainActivity" > <FrameLayout android:id="@+id/fl_container" android:layout_width="fill_parent" android:layout_weight="1" android:layout_height="0dip" > </FrameLayout> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#22000000" android:orientation="horizontal" > <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="setting01" android:text="蓝牙设置" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="setting02" android:text="声音设置" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="setting03" android:text="显示设置" /> </LinearLayout> </LinearLayout>
3个fragment：
蓝牙fragment： <?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="我是蓝牙设置" android:textAppearance="?android:attr/textAppearanceLarge" /> <RadioButton android:id="@+id/radioButton1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="RadioButton" /> <ToggleButton android:id="@+id/toggleButton1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="ToggleButton" /> </LinearLayout> 显示fragment： <?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="我是显示设置" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="CheckBox" /> <RadioButton android:id="@+id/radioButton1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="RadioButton" /> </LinearLayout> 声音fragment： <?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="我是声音设置" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="CheckBox" /> </LinearLayout>
主Activity：
package com.itheima.fragementdemo; import android.app.Activity; import android.app.FragmentManager; import android.app.FragmentTransaction; import android.os.Bundle; import android.view.View; public class MainActivity extends Activity { private FragmentManager fm;//管理所有Fragment，更新页面的时候要么同时更新成功要么同时更新失败所以有事物， BlueToothFragment f1; ShowFragment f3; SoundFragment f2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); fm = getFragmentManager(); initFragment(); //事务的概念 FragmentTransaction ft = fm.beginTransaction(); ft.replace(R.id.fl_container, f1); ft.commit();//保证了 要么同时成功,要么同时失败 } private void initFragment() { f1 = new BlueToothFragment();//Fragment是直接new出来的 f2 = new SoundFragment(); f3 = new ShowFragment(); } //蓝牙点击事件 public void setting01(View view) { //事物开始的时候实例化ft，事物结束的时候提交事物，提交后事物就过期了，所以每次都要初始化ft FragmentTransaction ft = fm.beginTransaction();// ft.replace(R.id.fl_container, f1); ft.commit();//保证了 要么同时成功,要么同时失败，保证了页面不花屏。 } //声音点击事件 public void setting02(View view) { //事务的概念 FragmentTransaction ft = fm.beginTransaction(); ft.replace(R.id.fl_container, f2); ft.commit();//保证了 要么同时成功,要么同时失败 } //显示点击事件 public void setting03(View view) { //事务的概念 FragmentTransaction ft = fm.beginTransaction(); ft.replace(R.id.fl_container, f3); ft.commit();//保证了 要么同时成功,要么同时失败 } }
3个fragment java代码
蓝牙： package com.itheima.fragementdemo; import android.app.Fragment; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; public class BlueToothFragment extends Fragment { //显示Fragment的ui的，不需要在清单文件配置任何内容 @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.blue_tooth_layout, null); } } 声音 package com.itheima.fragementdemo; import android.app.Fragment; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; public class SoundFragment extends Fragment { //显示Fragment的ui的 @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.sound_layout, null); } } 显示 package com.itheima.fragementdemo; import android.app.Fragment; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; public class ShowFragment extends Fragment { //显示Fragment的ui的 @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.show_layout, null); } }
##Fragment的向下兼容，兼容低版本
>使用support-v4的jar包
>1. MainActivity extends FragmentActivity
>2. 所有的fragment的导包, android.support.v4.app.Fragment
>3. getSupportFragmentManager();
>4. 注意两个导包
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
package com.itheima.fragementdemo; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentTransaction; import android.view.View; public class MainActivity extends FragmentActivity { private FragmentManager fm; BlueToothFragment f1; ShowFragment f3; SoundFragment f2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //为了向下版本兼容采用v4包里面的FragmentManager fm = getSupportFragmentManager(); initFragment(); //事务的概念 FragmentTransaction ft = fm.beginTransaction(); ft.replace(R.id.fl_container, f1); ft.commit();//保证了 要么同时成功,要么同时失败 } private void initFragment() { f1 = new BlueToothFragment(); f2 = new SoundFragment(); f3 = new ShowFragment(); } //蓝牙 public void setting01(View view) { //事务的概念 FragmentTransaction ft = fm.beginTransaction(); ft.replace(R.id.fl_container, f1); ft.commit();//保证了 要么同时成功,要么同时失败 } //声音 public void setting02(View view) { //事务的概念 FragmentTransaction ft = fm.beginTransaction(); ft.replace(R.id.fl_container, f2); ft.commit();//保证了 要么同时成功,要么同时失败 } //显示 public void setting03(View view) { //事务的概念 FragmentTransaction ft = fm.beginTransaction(); ft.replace(R.id.fl_container, f3); ft.commit();//保证了 要么同时成功,要么同时失败 } }
实现效果:
