android学习之ViewPager 初步使用

----------------ViewPager的功能就是可以使视图滑动

大概步骤 1所需要的对象 List<View> 用于装载ImageView 对象 根据图片数量把 图片依次添加设置到ImageView中 然后将ImageView 添加到List<View>中

2.设置ViewPager的apapter重写PagerAdapter方法

3.设置adapter

注意 需要导包：

android.support.v4

效果图





直接上代码：

public class MainActivity extends Activity {
private List<View> views;
private ViewPager viewpager;
private ViewPageAdapter adapter;
private Integer images[]={
R.drawable.a,
R.drawable.b,
R.drawable.c,
R.drawable.d,
R.drawable.e,
R.drawable.f,
R.drawable.g
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LayoutInflater inflater=getLayoutInflater();
views=new ArrayList<View>();
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.FILL_PARENT);
for(int i=0;i<images.length;i++){
ImageView iv=new ImageView(this);
iv.setLayoutParams(params);   //设置布局大小和LinearLayout一样
iv.setScaleType(ScaleType.FIT_XY);
iv.setImageResource(images[i]);
views.add(iv);
}
viewpager=(ViewPager) findViewById(R.id.viewpager);
adapter=new ViewPageAdapter(views);
viewpager.setAdapter(adapter);
//绑定回调函数
viewpager.setOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int arg0) {
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {

}
});
}

}

adapter:

package com.example.test_viewpager;

import java.util.List;

import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;

public class ViewPageAdapter extends PagerAdapter {
private List<View> views;

public ViewPageAdapter(List<View> views) {
this.views=views;
}
@Override
public void destroyItem(View view, int arg1, Object arg2) {
// TODO Auto-generated method stub
((ViewPager)view).removeView(views.get(arg1));  //移除
}
//完成更新
@Override
public void finishUpdate(View view) {
}
//获得总数
@Override
public int getCount() {
if(views!=null){
return views.size();
}
return 0;
}
//实例化Item
@Override
public Object instantiateItem(View view, int arg1) {
((ViewPager)view).addView(views.get(arg1),0);
return views.get(arg1);
}

@Override
public boolean isViewFromObject(View view, Object arg1) {
// TODO Auto-generated method stub
return view==arg1;
}
//恢复状态
@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
// TODO Auto-generated method stub

}
//保存状态
@Override
public Parcelable saveState() {
// TODO Auto-generated method stub
return null;
}
//启动更新
@Override
public void startUpdate(View arg0) {
// TODO Auto-generated method stub

}

}

xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>

</LinearLayout>