Android Fragment 应用

1、使用Fragment 可以方便的替代TabActivity、ViewGroup

2、同时也省去了在AndroidManifest.xml文件中 添加相应的Activity 

3、Fragment 是3.0之后的功能，如果想向下兼容我们在导包时一定要注意了，该导入 import android.support.v4.app.FragmentActivity; 而不是 import android.app.Fragment;

4、同时向下兼容我们的Activity 要继承 FragmentActivity 而不是 Activity 

5、核心代码：

package com.example.testdialog;import android.annotation.SuppressLint;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;import android.view.View.OnClickListener;import android.widget.TextView;@SuppressLint("NewApi")public class MainActivity extends FragmentActivity implements OnClickListener {    private TextView tab1 = null;    private TextView tab2 = null;    private FragmentManager fm = null;    private FragmentTransaction ft = null;

    private LinearLayout content = null;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        findViewById();        fm = getSupportFragmentManager();    }    private void findViewById() {

this.content = (LinearLayout)this.findViewById(R.id.content);        this.tab1 = (TextView) this.findViewById(R.id.tab1);        this.tab2 = (TextView) this.findViewById(R.id.tab2);        this.tab1.setOnClickListener(this);        this.tab2.setOnClickListener(this);    }    @Override    public void onClick(View v) {        ft = fm.beginTransaction();        switch (v.getId()) {        case R.id.tab1:            ft.replace(R.id.content, new MyFragment1());            break;        case R.id.tab2:            ft.replace(R.id.content, new MyFragment2());            break;        default:            break;        }        ft.commit();    }}

activity_main.xml 文件：

<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"    tools:context=".MainActivity" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal" >        <TextView            android:id="@+id/tab1"            android:layout_width="0dip"            android:layout_height="wrap_content"            android:layout_weight="1"            android:gravity="center"            android:text="Tab1" />        <TextView            android:id="@+id/tab2"            android:layout_width="0dip"            android:layout_height="wrap_content"            android:layout_weight="1"            android:gravity="center"            android:text="Tab2" />        <TextView            android:id="@+id/tab3"            android:layout_width="0dip"            android:layout_height="wrap_content"            android:layout_weight="1"            android:gravity="center"            android:text="Tab3" />        <TextView            android:id="@+id/tab4"            android:layout_width="0dip"            android:layout_height="wrap_content"            android:layout_weight="1"            android:gravity="center"            android:text="Tab2" />    </LinearLayout>    <LinearLayout        android:id="@+id/content"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_marginTop="20dip"        android:orientation="horizontal" >    </LinearLayout></LinearLayout>

MyFragment1.java 

package com.example.testdialog;import android.annotation.SuppressLint;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.Button;@SuppressLint("NewApi")public class MyFragment1 extends Fragment {    private Button button1 = null;    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {        View view = inflater.inflate(R.layout.fragment1, null);        button1 = (Button) view.findViewById(R.id.button1);        return view;    }}

6、这样我们就可以在相应的 Fragment 中做我们的UI设计了