android自动划屏实现,OSC首发：android中的左右滑屏实现ByViewPager

先看效果&＃xff0c;就是左右滑屏的效果

具体实现详解

android compatibility package, revision 3在7月份发布后&＃xff0c;其中有个ViewPager引起了我的注意

官方的描述&＃xff1a;

ViewPager的下载与安装

首先通过SDK Manager更新最新版android compatibility package, revision 3

更新后&＃xff0c;在eclipse中工程上点击右键&＃xff0c;选择android tools -> add compatibility library即可完成安装

实际上就是一个jar包&＃xff0c;手工导到工程中也可

jar包所在位置是\android-sdk\extras\android\compatibility\v4\android-support-v4.jar

至此准备环境已经ok

下边还是通过代码进行说话吧

准备布局文件

viewpager_layout.xml

android:layout_width&＃61;"fill_parent"

android:layout_height&＃61;"fill_parent" android:orientation&＃61;"vertical">

android:id&＃61;"&＃64;&＃43;id/viewpagerLayout" android:layout_height&＃61;"fill_parent" android:layout_width&＃61;"fill_parent"/>

android:layout_width&＃61;"fill_parent"

android:layout_height&＃61;"fill_parent" android:orientation&＃61;"vertical">

android:layout_width&＃61;"fill_parent"

android:layout_height&＃61;"fill_parent" android:orientation&＃61;"vertical">

android:layout_width&＃61;"fill_parent"

android:layout_height&＃61;"fill_parent" android:orientation&＃61;"vertical">

package a.b;

import java.util.ArrayList;

import java.util.List;

import android.app.Activity;

import android.os.Bundle;

import android.os.Parcelable;

import android.support.v4.view.PagerAdapter;

import android.support.v4.view.ViewPager;

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

import android.util.Log;

import android.view.LayoutInflater;

import android.view.View;

import android.widget.EditText;

public class TestViewPager extends Activity {

private ViewPager myViewPager;

private MyPagerAdapter myAdapter;

private LayoutInflater mInflater;

private List mListViews;

private View layout1 &＃61; null;

private View layout2 &＃61; null;

private View layout3 &＃61; null;

&＃64;Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.viewpager_layout);

myAdapter &＃61; new MyPagerAdapter();

myViewPager &＃61; (ViewPager) findViewById(R.id.viewpagerLayout);

myViewPager.setAdapter(myAdapter);

mListViews &＃61; new ArrayList();

mInflater &＃61; getLayoutInflater();

layout1 &＃61; mInflater.inflate(R.layout.layout1, null);

layout2 &＃61; mInflater.inflate(R.layout.layout2, null);

layout3 &＃61; mInflater.inflate(R.layout.layout3, null);

mListViews.add(layout1);

mListViews.add(layout2);

mListViews.add(layout3);

//初始化当前显示的view

myViewPager.setCurrentItem(1);

//初始化第二个view的信息

EditText v2EditText &＃61; (EditText)layout2.findViewById(R.id.editText1);

v2EditText.setText("动态设置第二个view的值");

myViewPager.setOnPageChangeListener(new OnPageChangeListener() {

&＃64;Override

public void onPageSelected(int arg0) {

Log.d("k", "onPageSelected - " &＃43; arg0);

//activity从1到2滑动&＃xff0c;2被加载后掉用此方法

View v &＃61; mListViews.get(arg0);

EditText editText &＃61; (EditText)v.findViewById(R.id.editText1);

editText.setText("动态设置#"&＃43;arg0&＃43;"edittext控件的值");

}

&＃64;Override

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

Log.d("k", "onPageScrolled - " &＃43; arg0);

//从1到2滑动&＃xff0c;在1滑动前调用

}

&＃64;Override

public void onPageScrollStateChanged(int arg0) {

Log.d("k", "onPageScrollStateChanged - " &＃43; arg0);

//状态有三个0空闲&＃xff0c;1是增在滑行中&＃xff0c;2目标加载完毕

/**

* Indicates that the pager is in an idle, settled state. The current page

* is fully in view and no animation is in progress.

*/

//public static final int SCROLL_STATE_IDLE &＃61; 0;

/**

* Indicates that the pager is currently being dragged by the user.

*/

//public static final int SCROLL_STATE_DRAGGING &＃61; 1;

/**

* Indicates that the pager is in the process of settling to a final position.

*/

//public static final int SCROLL_STATE_SETTLING &＃61; 2;

}

});

}

private class MyPagerAdapter extends PagerAdapter{

&＃64;Override

public void destroyItem(View arg0, int arg1, Object arg2) {

Log.d("k", "destroyItem");

((ViewPager) arg0).removeView(mListViews.get(arg1));

}

&＃64;Override

public void finishUpdate(View arg0) {

Log.d("k", "finishUpdate");

}

&＃64;Override

public int getCount() {

Log.d("k", "getCount");

return mListViews.size();

}

&＃64;Override

public Object instantiateItem(View arg0, int arg1) {

Log.d("k", "instantiateItem");

((ViewPager) arg0).addView(mListViews.get(arg1),0);

return mListViews.get(arg1);

}

&＃64;Override

public boolean isViewFromObject(View arg0, Object arg1) {

Log.d("k", "isViewFromObject");

return arg0&＃61;&＃61;(arg1);

}

&＃64;Override

public void restoreState(Parcelable arg0, ClassLoader arg1) {

Log.d("k", "restoreState");

}

&＃64;Override

public Parcelable saveState() {

Log.d("k", "saveState");

return null;

}

&＃64;Override

public void startUpdate(View arg0) {

Log.d("k", "startUpdate");

}

}

}在实机上测试后&＃xff0c;非常流畅&＃xff0c;这也就是说官方版的左右滑屏控件已经实现

目前&＃xff0c;关于viewpager的文章非常少&＃xff0c;本文是通过阅读viewpager源代码分析出的写法

当然此文章仅是抛砖引玉&＃xff0c;而且属于框架式程序&＃xff0c;目的就是让读者了解API的基本用法

希望这篇原创文章对大家有帮助

欢迎感兴趣的朋友一起讨论

共同学习&＃xff0c;共同进步

另外&＃xff0c;ViewPager的注释上有这么一段话&＃xff0c;大体意思是该控件目前属于早期实现&＃xff0c;后续会有修改

/**

* Layout manager that allows the user to flip left and right

* through pages of data. You supply an implementation of a

* {&＃64;link PagerAdapter} to generate the pages that the view shows.

*

*

Note this class is currently under early design and

* development. The API will likely change in later updates of

* the compatibility library, requiring changes to the source code

* of apps when they are compiled against the newer version.

*/