android自定义实现抽屉SlidingDrawer的功能

 

android自定义实现抽屉SlidingDrawer的功能

分类： android 2013-07-15 16:28  97人阅读  评论(0)  收藏  举报

自定义拖动

最近项目中需要实现上拉功能，首先想到的就是Android本身自带的抽屉SlidingDrawer，最后也实现了不过，出现的问题就是设置背景色问题，handler和content是两个不同的部分，这就造成图片要做成两部分，从而产生两个部分图片看起来不是一个整体，而且我这个上拉功能，里面要实现一个水平滚动功能，而SlidingDrawer还有其他的限制，同时官方给出api 17以后，这个功能已经废弃，所以自己自定这样一个上拉功能是必须的。

这里我是继承LinearLayout同时实现GestureDetector.OnGestureListener来实现上拉功能。下面是代码：

 package com.example.test;

 import android.content.Context;
 import android.os.AsyncTask;
 import android.util.AttributeSet;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.widget.LinearLayout;
 import android.widget.RelativeLayout;

 public class PanelBom extends LinearLayout implements GestureDetector.OnGestureListener{

     GestureDetector mGesture = null;
     private boolean isScrolling = false;
     private int MAX_HEIGHT = 80;//拖动的最大高度,当前布局位于父布局下面-80位置，这个仅仅是调试参数，这个变量是动态设置的。
     private float mScrollX; // 滑块滑动距离
     public PanelBom(Context context) {
         super(context);
         init();
     }
     public PanelBom(Context context, AttributeSet attrs) {
         super(context, attrs);
         init();
     }
     //初始化一些参数
     public void init(){
         mGesture = new GestureDetector(this);
         mGesture.setIsLongpressEnabled(false);
         setBackgroundResource(R.drawable.button_bar);
     }

     @Override
     public boolean onTouchEvent(MotionEvent event) {
         if (MotionEvent.ACTION_UP == event.getAction() && isScrolling == true) {
             RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams)getLayoutParams();
             // 缩回去
             if (layoutParams.bottomMargin < -MAX_HEIGHT / 2) {
                 new AsynMove().execute(-20);//负--往下
             } else {
                 new AsynMove().execute(20);//正--往上
             }
         }
         return mGesture.onTouchEvent(event);
     }
     //Touch down时触发
     @Override
     public boolean onDown(MotionEvent e) {
         mScrollX = 0;
         isScrolling = false;
         // 将之改为true，不然事件不会向下传递.
         return true;
     }
     //Touch了还没有滑动时触发
     @Override
     public void onShowPress(MotionEvent e) {

     }
     @Override
     public boolean onSingleTapUp(MotionEvent e) {
         RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) getLayoutParams();
         // 说明在上面，要往下
         if (layoutParams.bottomMargin >= 0) {
             new AsynMove().execute(-20);//负--往下
         } else {
             new AsynMove().execute(20);//正--往上
         }
         return true;
     }
     //Touch了滑动时触发
     @Override
     public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
             float distanceY) {
         isScrolling = true;
         mScrollX += distanceY;
         RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams)getLayoutParams();
         layoutParams.bottomMargin += mScrollX;
         if (layoutParams.bottomMargin >= 0) {
             isScrolling = false;// 拖过头了不需要再执行AsynMove了
             layoutParams.bottomMargin = 0;
         } else if (layoutParams.bottomMargin <= -MAX_HEIGHT) {
             // 拖过头了不需要再执行AsynMove了
             isScrolling = false;
             layoutParams.bottomMargin = -MAX_HEIGHT;
         }
         setLayoutParams(layoutParams);
         return false;
     }
     //Touch了不移动一直Touch down时触发
     @Override
     public void onLongPress(MotionEvent e) {

     }
     //Touch了滑动一点距离后，up时触发。
     @Override
     public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
             float velocityY) {
         return false;
     }
     //异步更新布局的位置
     class AsynMove extends AsyncTask<Integer, Integer, Void> {
         @Override
         protected Void doInBackground(Integer... params) {
             int times = 0;
             int divi = Math.abs(params[0]);
             if (MAX_HEIGHT % divi == 0)// 整除
                 times = MAX_HEIGHT / Math.abs(params[0]);
             else
                 times = MAX_HEIGHT / divi + 1;// 有余数

             for (int i = 0; i < times; i++) {
                 publishProgress(params[0]);
                 try {
                     Thread.sleep(divi);
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }
             }
             return null;
         }
         @Override
         protected void onProgressUpdate(Integer... values) {
             RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) getLayoutParams();
             if (values[0] < 0) {
                 layoutParams.bottomMargin = Math.max(layoutParams.bottomMargin + values[0], -MAX_HEIGHT);
             } else {
                 layoutParams.bottomMargin = Math.min(layoutParams.bottomMargin + values[0], 0);
             }
             setLayoutParams(layoutParams);

             super.onProgressUpdate(values);
         }
     }
 }

主界面：

 package com.example.test;

 import android.app.Activity;
 import android.os.Bundle;
 import android.widget.RelativeLayout;

 public class Main5 extends Activity{

     RelativeLayout Parent;
     PanelBom panelBom;
     RelativeLayout.LayoutParams parentParams;
     RelativeLayout.LayoutParams paneBomParams;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         Parent = new RelativeLayout(getApplicationContext());
         panelBom = new PanelBom(getApplicationContext());
         parentParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
         paneBomParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, 150);
         paneBomParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
         paneBomParams.bottomMargin = -80;
         Parent.addView(panelBom, paneBomParams);
         setContentView(Parent, parentParams);
     }

 }

实现的效果是：

拖拉，点击实现上拉功能，效果图如下: