Android编程中ViewPage判断左右滑动方向的方法

本文实例讲述了android编程中viewpage判断左右滑动方向的方法。分享给大家供大家参考，具体如下：

package com.meityitian.app.views;
import android.content.context; 
import android.support.v4.view.viewpager; 
import android.util.attributeset; 
import android.util.log; 
import com.meityitian.app.utils.debug; 
/** 
 * 重写，添加了判定滑动方向的方法 
 * @author zxy 
 * 
 */ 
public class meityitianviewpager extends viewpager { 
 private boolean left = false; 
 private boolean right = false; 
 private boolean isscrolling = false; 
 private int lastvalue = -1; 
 private changeviewcallback changeviewcallback = null; 
 public meityitianviewpager(context context, attributeset attrs) { 
  super(context, attrs); 
  init(); 
 } 
 public meityitianviewpager(context context) { 
  super(context); 
  init(); 
 } 
 /** 
  * init method . 
*/ 
 private void init() { 
  setonpagechangelistener(listener); 
 } 
 /** 
  * listener ,to get move direction . 
*/ 
 public onpagechangelistener listener = new onpagechangelistener() { 
  @override 
  public void onpagescrollstatechanged(int arg0) { 
   if (arg0 == 1) { 
    isscrolling = true; 
   } else { 
    isscrolling = false; 
   } 
   debug.infobytag("meityitianviewpager", 
     "meityitianviewpager onpagescrollstatechanged : arg0:" 
       + arg0); 
   if (arg0 == 2) { 
    debug.infobytag("meityitianviewpager", 
      "meityitianviewpager onpagescrollstatechanged direction left ? " 
        + left); 
    debug.infobytag("meityitianviewpager", 
      "meityitianviewpager onpagescrollstatechanged direction right ? " 
        + right); 
    //notify .... 
    if(changeviewcallback!=null){ 
     changeviewcallback.changeview(left, right); 
    } 
    right = left = false; 
   } 
  } 
  @override 
  public void onpagescrolled(int arg0, float arg1, int arg2) { 
   if (isscrolling) { 
    if (lastvalue > arg2) { 
     // 递减，向右侧滑动 
     right = true; 
     left = false; 
    } else if (lastvalue < arg2) { 
     // 递减，向右侧滑动 
     right = false; 
     left = true; 
    } else if (lastvalue == arg2) { 
     right = left = false; 
    } 
   } 
   log.i("meityitianviewpager", 
     "meityitianviewpager onpagescrolled last :arg2 ," 
       + lastvalue + ":" + arg2); 
   lastvalue = arg2; 
  } 
  @override 
  public void onpageselected(int arg0) { 
   if(changeviewcallback!=null){ 
    changeviewcallback.getcurrentpageindex(arg0); 
   } 
  } 
 }; 
 /** 
  * 得到是否向右侧滑动 
  * @return true 为右滑动 
*/ 
 public boolean getmoveright(){ 
  return right; 
 } 
 /** 
  * 得到是否向左侧滑动 
  * @return true 为左做滑动 
*/ 
 public boolean getmoveleft(){ 
  return left; 
 } 
 /** 
  * 滑动状态改变回调 
  * @author zxy 
  * 
*/ 
 public interface changeviewcallback{ 
  /** 
   * 切换视图 ？决定于left和right 。 
   * @param left 
   * @param right 
*/ 
  public void changeview(boolean left,boolean right); 
  public void getcurrentpageindex(int index); 
 } 
 /** 
  * set ... 
  * @param callback 
*/ 
 public void setchangeviewcallback(changeviewcallback callback){ 
  changeviewcallback = callback; 
 } 
}

希望本文所述对大家android程序设计有所帮助。