Android实现滑动侧边栏

package com.example.test; 
import android.content.Context; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.Scroller; 
public class SlidingMenu extends ViewGroup { 
private static final String TAG = SlidingMenu.class.getName(); 
private enum Scroll_State { 
Scroll_to_Open, Scroll_to_Close; 
} 
private Scroll_State state; 
private int mMostRecentX; 
private int downX; 
private boolean isOpen = false; 
private View menu; 
private View mainView; 
private Scroller mScroller; 
private OnSlidingMenuListener onSlidingMenuListener; 
public SlidingMenu(Context context, View main, View menu) { 
super(context); 
// TODO Auto-generated constructor stub 
setMainView(main); 
setMenu(menu); 
init(context); 
} 
private void init(Context context) { 
mScroller = new Scroller(context); 
} 
@Override 
protected void onLayout(boolean arg0, int l, int t, int r, int b) { 
// TODO Auto-generated method stub 
mainView.layout(l, t, r, b); 
menu.layout(-menu.getMeasuredWidth(), t, 0, b); 
} 
public void setMainView(View view) { 
mainView = view; 
addView(mainView); 
} 
public void setMenu(View view) { 
menu = view; 
addView(menu); 
} 
@Override 
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
// TODO Auto-generated method stub 
super.onMeasure(widthMeasureSpec, heightMeasureSpec); 
mainView.measure(widthMeasureSpec, heightMeasureSpec); 
menu.measure(widthMeasureSpec - 150, heightMeasureSpec); 
} 
@Override 
public boolean onTouchEvent(MotionEvent event) { 
switch (event.getAction()) { 
case MotionEvent.ACTION_DOWN: 
mMostRecentX = (int) event.getX(); 
downX = (int) event.getX(); 
break; 
case MotionEvent.ACTION_MOVE: 
int moveX = (int) event.getX(); 
int deltaX = mMostRecentX - moveX; 
// 如果在菜单打开时向右滑动及菜单关闭时向左滑动不会触发Scroll事件 
if ((!isOpen && (downX - moveX) < 0) 
|| (isOpen && (downX - moveX)   0)) { 
scrollBy(deltaX / 2, 0); 
} 
mMostRecentX = moveX; 
break; 
case MotionEvent.ACTION_UP: 
int upX = (int) event.getX(); 
int dx = upX - downX; 
if (!isOpen) {// 菜单关闭时 
// 向右滑动超过menu一半宽度才会打开菜单 
if (dx   menu.getMeasuredWidth() / 3) { 
state = Scroll_State.Scroll_to_Open; 
} else { 
state = Scroll_State.Scroll_to_Close; 
} 
} else {// 菜单打开时 
// 当按下时的触摸点在menu区域时，只有向左滑动超过menu的一半，才会关闭 
// 当按下时的触摸点在main区域时，会立即关闭 
if (downX < menu.getMeasuredWidth()) { 
if (dx < -menu.getMeasuredWidth() / 3) { 
state = Scroll_State.Scroll_to_Close; 
} else { 
state = Scroll_State.Scroll_to_Open; 
} 
} else { 
state = Scroll_State.Scroll_to_Close; 
} 
} 
smoothScrollto(); 
break; 
default: 
break; 
} 
return true; 
} 
private void smoothScrollto() { 
int scrollx = getScrollX(); 
switch (state) { 
case Scroll_to_Close: 
mScroller.startScroll(scrollx, 0, -scrollx, 0, 500); 
if (onSlidingMenuListener != null && isOpen) { 
onSlidingMenuListener.close(); 
} 
isOpen = false; 
break; 
case Scroll_to_Open: 
mScroller.startScroll(scrollx, 0, 
-scrollx - menu.getMeasuredWidth(), 0, 500); 
if (onSlidingMenuListener != null && !isOpen) { 
onSlidingMenuListener.close(); 
} 
isOpen = true; 
break; 
default: 
break; 
} 
} 
@Override 
public void computeScroll() { 
if (mScroller.computeScrollOffset()) { 
scrollTo(mScroller.getCurrX(), 0); 
} 
invalidate(); 
} 
public void open() { 
state = Scroll_State.Scroll_to_Open; 
smoothScrollto(); 
} 
public void close() { 
state = Scroll_State.Scroll_to_Close; 
smoothScrollto(); 
} 
public boolean isOpen() { 
return isOpen; 
} 
public void setOnSlidingMenuListener( 
OnSlidingMenuListener onSlidingMenuListener) { 
this.onSlidingMenuListener = onSlidingMenuListener; 
} 
public interface OnSlidingMenuListener { 
public void open(); 
public void close(); 
} 
} 

package com.example.test; 
import android.os.Bundle; 
import android.support.v4.app.FragmentActivity; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
public class MainActivity extends Activity { 
private Button openButton; 
private Button closeButton; 
private SlidingMenu mSlidingMenu; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
mSlidingMenu = new SlidingMenu(this, LayoutInflater 
.from(this).inflate(R.layout.fragment1, null), LayoutInflater 
.from(this).inflate(R.layout.fragment2, null)); 
setContentView(mSlidingMenu);//注意setContentView需要换为我们的SlidingMenu 
openButton = (Button) findViewById(R.id.button1); 
closeButton = (Button) findViewById(R.id.button_close); 
openButton.setOnClickListener(new OnClickListener() { 
@Override 
public void onClick(View arg0) { 
// TODO Auto-generated method stub 
mSlidingMenu.open(); 
} 
}); 
closeButton.setOnClickListener(new OnClickListener() { 
@Override 
public void onClick(View arg0) { 
// TODO Auto-generated method stub 
mSlidingMenu.close(); 
} 
}); 
} 
}