ViewPager的使用

时间:2024-04-26 08:35:55

在上培训课的时候,老师一直在将ViewPager是现在的主流,一直想去好好的了解一下,今天去网上学习了一下   ,做一个总结:

  ViewPager其实就是后来谷歌提供给我们的一个组件,就像TextView,Button一样,只不过它是ViewGroup,在使用它前要有v4的包,既然是组件,当然要在xml中定义,

  标签的样式基本是这样:

<android.support.v4.view.ViewPager
android:id="viewPager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>

  在xml文件内定义好了以后。接下来就是编辑Activity文件,最重要的就是实现一个适配器PagerAdapter,使用的方法和ListView里面实现BaseAdapter是一样的,下面是代码:

    	PagerAdapter myPagerAdapter=new PagerAdapter(){

			@Override
public int getCount() {
return viewList.size();
} @Override
public boolean isViewFromObject(View arg0, Object arg1) { return arg0==arg1;
} @Override
public void destroyItem(ViewGroup container, int position,
Object object) { container.removeView(viewList.get(position));
} @Override
public CharSequence getPageTitle(int position) { return titleList.get(position);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
container.addView(viewList.get(position));
return viewList.get(position);
} };

  适配器必须要实现的是四个方法:分别是getCount(),isViewFromObject(View arg0, Object arg1),instantiateItem(ViewGroup container, int position),destroyItem(ViewGroup container, int position,Object object)具体的使用就看文档了。在适配器里面我们还可以定义标签等一些属性。

  下面是全部代码:

  Activity:

package com.example.viewpager;

import java.util.ArrayList;
import java.util.List; import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.PagerTabStrip;
import android.support.v4.view.PagerTitleStrip;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button; public class MainActivity extends Activity {
private ViewPager viewPager=null;
private List<View> viewList=null;
private List<String> titleList=null;
private PagerTabStrip pageTab=null; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setValue();
}
private void setValue(){
viewPager=(ViewPager) findViewById(R.id.viewPager);
pageTab=(PagerTabStrip) findViewById(R.id.pagerTab);
pageTab.setTextSpacing(20);
pageTab.setTabIndicatorColor(Color.YELLOW);
pageTab.setDrawFullUnderline(false);
pageTab.setBackgroundColor(Color.BLUE);
LayoutInflater flater=LayoutInflater.from(this);
View view1=flater.inflate(R.layout.layout_01, null);
View view2=flater.inflate(R.layout.layout_02, null);
View view3=flater.inflate(R.layout.layout_03, null);
viewList=new ArrayList<View>();
viewList.add(view1);
viewList.add(view2);
viewList.add(view3);
titleList=new ArrayList<String>();
titleList.add("标签一");
titleList.add("标签二");
titleList.add("标签三");
PagerAdapter myPagerAdapter=new PagerAdapter(){ @Override
public int getCount() {
return viewList.size();
} @Override
public boolean isViewFromObject(View arg0, Object arg1) { return arg0==arg1;
} @Override
public void destroyItem(ViewGroup container, int position,
Object object) { container.removeView(viewList.get(position));
} @Override
public CharSequence getPageTitle(int position) { return titleList.get(position);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
container.addView(viewList.get(position));
return viewList.get(position);
} };
viewPager.setAdapter(myPagerAdapter);
} @Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
} }

  xml:

<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"
>
<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
>
<android.support.v4.view.PagerTabStrip
android:id="@+id/pagerTab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top"
/>
</android.support.v4.view.ViewPager> </LinearLayout>

其他三个子页面我就不复制了。