Android ViewPager 实现多个页面切换滑动

使用ViewPager这个类可以轻松实现多个页面的滑动功能，而且相对viewgroup来讲要简单容易一些，在此之前我们需要导入 android-support-v4.jar这个jar包，是google提供的扩展包，位置路径为 android-sdk-windows\extras\android\support\v4\ android-support-v4.jar，如果没有找到，需要打开Android SDK Manager在Extras中进行下载，最后记得引入工程中并build path。

在本示例中，我参考了几个demo整理出来的viewpager的最基本用法，制作了一个类似新闻导航功能的界面，每个页面的下方有对应的项目符号，当页面进行切换的时候项目符号也随之变化，下面是实现后的图片：

java代码：

packagecom.cogent.viewpager;

importjava.util.ArrayList;

importandroid.app.Activity;
importandroid.os.Bundle;
importandroid.os.Parcelable;
importandroid.support.v4.view.PagerAdapter;
importandroid.support.v4.view.ViewPager;
importandroid.support.v4.view.ViewPager.OnPageChangeListener;
importandroid.view.LayoutInflater;
importandroid.view.View;
importandroid.view.ViewGroup;
importandroid.view.ViewGroup.LayoutParams;
importandroid.view.Window;
importandroid.widget.ImageView;

public classViewPagerGuideActivity extendsActivity{
privateViewPagerviewPager;
/** 装分页显示的view的数组 */
privateArrayList<View>pageViews;
privateImageViewimageView;
/** 将小圆点的图片用数组表示 */
privateImageView[]imageViews;
// 包裹滑动图片的LinearLayout
privateViewGroupviewPics;
// 包裹小圆点的LinearLayout
privateViewGroupviewPoints;
/** Calledwhentheactivityisfirstcreated. */
@Override
public voidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE); // 设置无标题栏

// 将要分页显示的View装入数组中
LayoutInflaterinflater=getLayoutInflater();
pageViews= newArrayList<View>();
pageViews.add(inflater.inflate(R.layout.page01, null));
pageViews.add(inflater.inflate(R.layout.page02, null));
pageViews.add(inflater.inflate(R.layout.page03, null));

// 创建imageviews数组，大小是要显示的图片的数量
imageViews= newImageView[pageViews.size()];
// 从指定的XML文件加载视图
viewPics=(ViewGroup)inflater.inflate(R.layout.view_pics, null);

// 实例化小圆点的linearLayout和viewpager
viewPoints=(ViewGroup)viewPics.findViewById(R.id.viewGroup);
viewPager=(ViewPager)viewPics.findViewById(R.id.guidePages);

// 添加小圆点的图片
for( inti=0;i<pageViews.size();i++){
imageView= newImageView(ViewPagerGuideActivity. this);
// 设置小圆点imageview的参数
imageView.setLayoutParams( newLayoutParams(20,20)); // 创建一个宽高均为20的布局
imageView.setPadding(20,0,20,0);
// 将小圆点layout添加到数组中
imageViews[i]=imageView;

// 默认选中的是第一张图片，此时第一个小圆点是选中状态，其他不是
if(i==0){
imageViews[i].setBackgroundResource(R.drawable.page_indicator_focused);
} else{
imageViews[i].setBackgroundResource(R.drawable.page_indicator);
}

// 将imageviews添加到小圆点视图组
viewPoints.addView(imageViews[i]);
}

// 显示滑动图片的视图
setContentView(viewPics);

// 设置viewpager的适配器和监听事件
viewPager.setAdapter( newGuidePageAdapter());
viewPager.setOnPageChangeListener( newGuidePageChangeListener());
}


classGuidePageAdapter extendsPagerAdapter{

// 销毁position位置的界面
@Override
public voiddestroyItem(Viewv, intposition,Objectarg2){
// TODOAuto-generatedmethodstub
((ViewPager)v).removeView(pageViews.get(position));

}

@Override
public voidfinishUpdate(Viewarg0){
// TODOAuto-generatedmethodstub

}

// 获取当前窗体界面数
@Override
public intgetCount(){
// TODOAuto-generatedmethodstub
returnpageViews.size();
}

// 初始化position位置的界面
@Override
publicObjectinstantiateItem(Viewv, intposition){
// TODOAuto-generatedmethodstub
((ViewPager)v).addView(pageViews.get(position));
returnpageViews.get(position);
}

// 判断是否由对象生成界面
@Override
public booleanisViewFromObject(Viewv,Objectarg1){
// TODOAuto-generatedmethodstub
returnv==arg1;
}



@Override
public voidstartUpdate(Viewarg0){
// TODOAuto-generatedmethodstub

}

@Override
public intgetItemPosition(Objectobject){
// TODOAuto-generatedmethodstub
return super.getItemPosition(object);
}

@Override
public voidrestoreState(Parcelablearg0,ClassLoaderarg1){
// TODOAuto-generatedmethodstub

}

@Override
publicParcelablesaveState(){
// TODOAuto-generatedmethodstub
return null;
}
}


classGuidePageChangeListener implementsOnPageChangeListener{

@Override
public voidonPageScrollStateChanged( intarg0){
// TODOAuto-generatedmethodstub

}

@Override
public voidonPageScrolled( intarg0, floatarg1, intarg2){
// TODOAuto-generatedmethodstub

}

@Override
public voidonPageSelected( intposition){
// TODOAuto-generatedmethodstub
for( inti=0;i<imageViews.length;i++){
imageViews[position].setBackgroundResource(R.drawable.page_indicator_focused);
// 不是当前选中的page，其小圆点设置为未选中的状态
if(position!=i){
imageViews[i].setBackgroundResource(R.drawable.page_indicator);
}
}

}
}
}

主页面的布局：

?

<?xml version= "1.0" encoding= "utf-8" ?> <FrameLayout xmlns:android= "http://schemas.android.com/apk/res/android" android:layout_width= "fill_parent" android:layout_height= "fill_parent" android:orientation= "vertical" > <LinearLayout android:id= "@+id/linearLayout1" android:layout_width= "fill_parent" android:layout_height= "wrap_content" android:orientation= "vertical" > <include layout= "@layout/page_header" /> <android.support.v4.view.ViewPager android:id= "@+id/guidePages" android:layout_width= "fill_parent" android:layout_height= "wrap_content" /> </LinearLayout> <LinearLayout android:id= "@+id/linearLayout2" android:layout_width= "fill_parent" android:layout_height= "wrap_content" android:orientation= "vertical" > <RelativeLayout android:layout_width= "fill_parent" android:layout_height= "wrap_content" android:orientation= "vertical" > <LinearLayout android:id= "@+id/viewGroup" android:layout_width= "fill_parent" android:layout_height= "wrap_content" android:layout_alignParentBottom= "true" android:layout_marginBottom= "40dp" android:gravity= "center_horizontal" android:orientation= "horizontal" > </LinearLayout> </RelativeLayout> </LinearLayout> </FrameLayout>

标题栏的布局：

?

<?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= "wrap_content" android:orientation= "horizontal" android:background= "@drawable/title" android:gravity= "center_vertical" > <Button android:id= "@+id/btn_left" android:layout_width= "80dp" android:layout_height= "30dp" android:text= "返回" android:textSize= "15sp" android:textColor= "@android:color/white" android:background= "@drawable/header_btn" android:layout_margin= "5dp" /> <TextView android:id= "@+id/tvTitle" android:layout_width= "wrap_content" android:layout_height= "wrap_content" android:text= "奥运快报" android:textSize= "18sp" android:layout_weight= "1" android:ellipsize= "end" android:gravity= "center_horizontal" /> <Button android:id= "@+id/btn_right" android:layout_width= "80dp" android:layout_height= "30dp" android:text= "首页" android:textSize= "15sp" android:textColor= "@android:color/white" android:background= "@drawable/header_btn" android:layout_margin= "5dp" /> </LinearLayout>

　　

子页面的布局：

?

<?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" android:background= "@android:color/white" > <LinearLayout android:layout_width= "fill_parent" android:layout_height= "wrap_content" > <ImageView android:layout_width= "fill_parent" android:layout_height= "wrap_content" android:src= "@drawable/pic_lindan" /> </LinearLayout> <LinearLayout android:layout_width= "fill_parent" android:layout_height= "wrap_content" android:layout_marginTop= "10dp" android:layout_marginBottom= "10dp" android:layout_marginLeft= "30dp" android:layout_marginRight= "30dp" android:background= "@drawable/divider_horizontal_line" > </LinearLayout> <LinearLayout android:layout_width= "fill_parent" android:layout_height= "fill_parent" > <TextView android:layout_width= "fill_parent" android:layout_height= "wrap_content" android:layout_marginRight= "30dp" android:layout_marginLeft= "30dp" android:textColor= "@android:color/black" android:text= "@string/string_lindan" /> </LinearLayout> </LinearLayout>

其余子页面的布局类。