使用ViewPager+Fragment实现选项卡切换效果

2022-11-17 21:12:15

实现效果

本实例主要实现用ViewPage和Fragment实现选项卡切换效果，选项卡个数为3个，点击选项卡或滑动屏幕会切换Fragment并实现选项卡下方下边框条跟随移动效果。

本程序用android4.2.2真机调试，为方便部署，我使用adbWireless做为部署工具，电脑和手机接入同一局域网，在PC端输入名称 adb connect 手机端ip 默认连接5555端口。之后再Eclipse的Devices中即可看到介入设备。前提是android系统需要Root。如下图：

设计实现

创建项目（此过程不做赘述）
在activity_main.xml中设置布局。xml内容如下：

<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="com.example.fengzhengapp.MainActivity" >

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="48dp"

        android:orientation="horizontal" >

        <TextView

            android:id="@+id/tv_hot"

            android:layout_width="wrap_content"

            android:layout_height="fill_parent"

            android:layout_weight="1.0"

            android:background="#ffEAEAEA"

            android:gravity="center"

            android:text="@string/tab_hot"

            android:textSize="18sp" />

        <TextView

            android:id="@+id/tv_news"

            android:layout_width="wrap_content"

            android:layout_height="fill_parent"

            android:layout_weight="1.0"

            android:background="#ffEAEAEA"

            android:gravity="center"

            android:text="@string/tab_news"

            android:textSize="18sp" />

        <TextView

            android:id="@+id/tv_fav"

            android:layout_width="wrap_content"

            android:layout_height="fill_parent"

            android:layout_weight="1.0"

            android:background="#ffEAEAEA"

            android:gravity="center"

            android:text="@string/tab_favorite"

            android:textSize="18sp" />

    </LinearLayout>

    <ImageView

        android:id="@+id/cursor"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:scaleType="matrix"

        android:src="@drawable/bgborder" />

    <android.support.v4.view.ViewPager

        android:id="@+id/myViewPager"

        android:layout_width="match_parent"

        android:layout_height="0dp"

        android:layout_weight="1"

        android:flipInterval="30" >

    </android.support.v4.view.ViewPager>

</LinearLayout>

上面布局页实现的效果如下：

接下来，增加3个Fragment布局页，分别在里面填充简单的内容

第一个：

<?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/txtHot"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_weight="1"

        android:text="this is the hot tab" >

    </TextView>

</LinearLayout>

第二个：

<?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/txtNews"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_weight="1"

        android:text="this is the news tab" >

    </TextView>

</LinearLayout>

第三个:

<?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/txtFav"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_weight="1"

        android:text="this is the Fav tab" >

    </TextView>

</LinearLayout>

以上3个Fragment的布局文件已创建完毕，每个文件中只显示简单的文本内容，用做演示。

加载3个Fragment到Activity中。

首先实现3个Fragment对应的后台类

热点布局页对应的类：

import android.os.Bundle;

import android.support.v4.app.Fragment;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

public class FragmentHot extends Fragment {

	@Override

	public View onCreateView(LayoutInflater inflater, ViewGroup container,

			Bundle savedInstanceState) {

		View view = inflater.inflate(R.layout.fragmenthot, container, false);

		return view;

	}

}

news布局页对应的类：

import android.os.Bundle;

import android.support.v4.app.Fragment;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

public class FragmentNews extends Fragment {

	@Override

	public View onCreateView(LayoutInflater inflater, ViewGroup container,

			Bundle savedInstanceState) {

		View view = inflater.inflate(R.layout.fragmentnews, container, false);

		return view;

	}

}

收藏布局页对应的类：

import android.os.Bundle;

import android.support.v4.app.Fragment;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

public class FragmentFavorite extends Fragment {

	@Override

	public View onCreateView(LayoutInflater inflater, ViewGroup container,

			Bundle savedInstanceState) {

		View view = inflater.inflate(R.layout.fragmentfav, container, false);

		return view;

	}

}

之后再activity中初始化这3个Fragment

注意要点：

Activity继承自FragmentActivity

要实现一个FragmentPagerAdapter，内容如下：

import java.util.ArrayList;

import android.support.v4.app.Fragment;

import android.support.v4.app.FragmentManager;

import android.support.v4.app.FragmentPagerAdapter;

public class MyFragmentAdapter extends FragmentPagerAdapter {

	ArrayList<Fragment> list;

	public MyFragmentAdapter(FragmentManager fm,ArrayList<Fragment> list){

		super(fm);

		this.list = list;

	}

	@Override

	public Fragment getItem(int arg0) {

		// TODO Auto-generated method stub

		return list.get(arg0);

	}

	@Override

	public int getCount() {

		// TODO Auto-generated method stub

		return list.size();

	}

}

然后在Activity中实现切换和动画效果，代码如下：

import java.util.ArrayList;

import android.app.Activity;

import android.graphics.BitmapFactory;

import android.graphics.Matrix;

import android.os.Bundle;

import android.support.v4.app.Fragment;

import android.support.v4.view.ViewPager;

import android.support.v4.view.ViewPager.OnPageChangeListener;

import android.util.DisplayMetrics;

import android.util.Log;

import android.view.Menu;

import android.view.View;

import android.support.v4.app.FragmentActivity;

import android.view.MenuItem;

import android.view.animation.Animation;

import android.view.animation.TranslateAnimation;

import android.widget.ImageView;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends FragmentActivity {

	private ViewPager mViewPager;

	private ArrayList fragments;

	private TextView view1, view2, view3;

    private int currIndex;

    private ImageView image;

    private static int bmpW;//横线图片宽度

    private static int offset;//图片移动的偏移量

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		initViewPager();

		InitTextView();

		InitImage();

	}

	@Override

	public boolean onCreateOptionsMenu(Menu menu) {

		// Inflate the menu; this adds items to the action bar if it is present.

		getMenuInflater().inflate(R.menu.main, menu);

		return true;

	}

	@Override

	public boolean onOptionsItemSelected(MenuItem item) {

		// Handle action bar item clicks here. The action bar will

		// automatically handle clicks on the Home/Up button, so long

		// as you specify a parent activity in AndroidManifest.xml.

		int id = item.getItemId();

		if (id == R.id.action_settings) {

			return true;

		}

		return super.onOptionsItemSelected(item);

	}

	private void InitTextView(){

		view1 = (TextView) findViewById(R.id.tv_hot);

		view2 = (TextView) findViewById(R.id.tv_news);

		view3 = (TextView) findViewById(R.id.tv_fav);

		view1.setOnClickListener(new txtListener(0));

		view2.setOnClickListener(new txtListener(1));

		view3.setOnClickListener(new txtListener(2));

	}

	//内部类 重写TextView点击事件

	public class txtListener implements View.OnClickListener{

		private int index = 0;

		public txtListener(int i){

			index = i;

		}

		@Override

		public void onClick(View v){

			mViewPager.setCurrentItem(index);

		}

	}

	/*

     * 初始化图片的位移像素

     */

    public void InitImage(){

        image = (ImageView)findViewById(R.id.cursor);

        bmpW = BitmapFactory.decodeResource(getResources(), R.drawable.bgborder).getWidth();

        DisplayMetrics dm = new DisplayMetrics();

        getWindowManager().getDefaultDisplay().getMetrics(dm);

        int screenW = dm.widthPixels;

        offset = (screenW/3 - bmpW)/2;

        Log.i("screenW",String.valueOf(screenW));

        Log.i("bmpW",String.valueOf(bmpW));

        Log.i("offset",String.valueOf(offset));

        //imgageview设置平移，使下划线平移到初始位置（平移一个offset）

        Matrix matrix = new Matrix();

        matrix.postTranslate(offset, 0);

        image.setImageMatrix(matrix);

    }

	private void initViewPager(){

		mViewPager = (ViewPager)findViewById(R.id.myViewPager);

		fragments = new ArrayList<Fragment>();

		Fragment fragmentHot = new FragmentHot();

		Fragment fragmentNews = new FragmentNews();

		Fragment fragmentFav = new FragmentFavorite();

		fragments.add(fragmentHot);

		fragments.add(fragmentNews);

		fragments.add(fragmentFav);

		mViewPager.setAdapter(new MyFragmentAdapter(getSupportFragmentManager(), fragments));

		mViewPager.setCurrentItem(0);

		mViewPager.setOnPageChangeListener(new myOnPageChangeListener());

	}

	public class myOnPageChangeListener implements OnPageChangeListener {

		private int one = offset*2 +bmpW;//两个相邻页面的偏移量

		@Override

		public void onPageScrolled(int arg0, float arg1, int arg2) {

		}

		@Override

		public void onPageScrollStateChanged(int arg0) {

			// TODO Auto-generated method stub

		}

		@Override

        public void onPageSelected(int arg0) {

            // TODO Auto-generated method stub

			Log.i("aaaaaaaaaaaaa",String.valueOf(arg0));

			Log.i("one",String.valueOf(one));

            Animation animation = new TranslateAnimation(currIndex*one,arg0*one,0,0);//平移动画

            currIndex = arg0;

            animation.setFillAfter(true);//动画终止时停留在最后一帧，不然会回到没有执行前的状态

            animation.setDuration(200);//动画持续时间0.2秒

            image.startAnimation(animation);//是用ImageView来显示动画的

            //int i = currIndex + 1;

           // Toast.makeText(MainActivity.this, "您选择了第"+i+"个页卡", Toast.LENGTH_SHORT).show();

        }

    }

}

源代码地址请访问这里：源码

码农公寓

实现效果

设计实现

热点布局页对应的类：

news布局页对应的类：

收藏布局页对应的类：

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