android自定义实现抽屉SlidingDrawer的功能

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: