自定义侧滑菜单

详细内容请看代码，注释很详细很详细：

1：先看xml文件，就是简单的两个线性布局，一个作为当前界面，一个作为隐藏的侧滑界面。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    tools:context="com.example.actionbar.SlideMenActivity" >


    <LinearLayout 
        android:id="@+id/menu"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="#ff00ff00"
        android:orientation="vertical"
        >
        
    </LinearLayout>
    <LinearLayout
        android:id="@+id/content"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="#ffff0000"
        android:orientation="vertical">
        </LinearLayout>

</LinearLayout>

2：activity的主要代码：

public class SlideMenActivity extends Activity implements View.OnTouchListener {
    /**
     * 手指每单位时间滑动200个像素
     */
    private static final int SPPED = 200;
    /**
     * 屏幕宽度
     */
    private int mScreenSidth;
    /**
     * menu的layout
     */
    private LinearLayout mMenuLayout;
    /**
     * content的layout
     */
    private LinearLayout mContentLayout;
    /**
     * menu的layout的Paramters
     */
    private LinearLayout.LayoutParams mMenuParams;
    /**
     * menu完全显示的时候给content的宽度值
     */
    private int mMenuPadding = 80;
    /**
     * menu最多滑到左边缘，值由menu布局的宽度决定，marginLeft到达此值之后，不能在减少
     */
    private int mLeftEdge;
    /**
     * 测速度的对象
     */
    private VelocityTracker mVelocityTracker;
    /**
     * 手指按下的X坐标
     */
    private float mXDown;
    /**
     * 手指移动时候的X坐标
     */
    private float mXMove;
    /**
     * 手指抬起的X坐标
     */
    private float mXUp;
    /**
     * menu是否再显示
     */
    private boolean mIsMenuVisible = false;
    

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_slide_men);
        initViewsAndValues();
        mContentLayout.setOnTouchListener(this);
        
        
    }
    
    /**
     * 初始化menu和content并且设置他们的位置
     */
     @SuppressLint("ServiceCast") 
     private void initViewsAndValues(){
         //得到屏幕的宽
         mScreenSidth = getResources().getDisplayMetrics().widthPixels;
         //找到控件
         mMenuLayout = (LinearLayout) findViewById(R.id.menu);
         mContentLayout = (LinearLayout) findViewById(R.id.content);
         //得到menu的parameter
         mMenuParams = (LinearLayout.LayoutParams) mMenuLayout.getLayoutParams();
        //将menu的宽度设置为屏幕宽度减去mMenuPading
         mMenuParams.width = mScreenSidth - mMenuPadding;
         //左边缘的值复制为menu宽度的负数，这样的话就可以将menu隐藏
         mLeftEdge = -mMenuParams.width;
         //将margin设置为mLeftEdge
         mMenuParams.leftMargin = mLeftEdge;
        //将content显示再屏幕上
         mContentLayout.getLayoutParams().width = mScreenSidth;
         
     }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        createVelocityTracker(event);
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            //记录按下的x坐标
            mXDown = event.getRawX();
            break;
        case MotionEvent.ACTION_MOVE:
            mXMove = event.getRawX();
            int distanceX = (int)(mXMove - mXDown);
            if(mIsMenuVisible){
                mMenuParams.leftMargin = distanceX;
            }else{
                mMenuParams.leftMargin = distanceX + mLeftEdge;
            }
            
            if(mMenuParams.leftMargin < mLeftEdge){
                //因为leftEdge是负数，就是menu已经隐藏完毕了，不能再往左隐藏了
                mMenuParams.leftMargin = mLeftEdge;
            }else if(mMenuParams.leftMargin > 0){
                 //menu显示完全了，不能再往右移动了
                mMenuParams.leftMargin = 0;
            }
            mMenuLayout.setLayoutParams(mMenuParams);
            break;
        case MotionEvent.ACTION_UP:
            mXUp = event.getRawX();
            if(wantToShowMenu()){
                if(shouldScrollToMenu()){
                    scrollToMenu();
                }else{
                    //条件不满足，吧menu隐藏
                    scrollToContent();
                }
            }else if(wantToShowContent()){
                if(shouldScrollToContent()){
                    scrollToContent();
                }else{
                    scrollToMenu();
                }
            }
            break;

        default:
            break;
        }
        
        recycleVelocityTrancker();
        return true;
    }
    
    /**
     * 创建VelocityTracker对象，针对于content的界面的滑动事件
     *
     * @param event
     */
    private void createVelocityTracker(MotionEvent event){
        if( null == mVelocityTracker){
            mVelocityTracker = VelocityTracker.obtain();
        }
        mVelocityTracker.addMovement(event);
    }
    /**
     * 判断手势是不是想要显示Content && menu处于显示状态
     *
     * @return
     */
    private boolean wantToShowContent(){
        return mXUp - mXDown < 0 && mIsMenuVisible;
    }
    /**
     * 是不是要显示menu && menu处于隐藏状态
     *
     * @return
     */
    private boolean wantToShowMenu(){
        return mXUp - mXDown > 0 && !mIsMenuVisible;
    }
    /**
     * 是否应该滑动出menu
     *
     * @return
     */
    private boolean shouldScrollToMenu(){
        return mXUp - mXDown > mScreenSidth/2 || getScrollVelocity() > SPPED;
    }
    /**
     * 是否应该让content全部显示出来
     *
     * @return
     */
    private boolean shouldScrollToContent(){
        return mXUp - mXDown < mScreenSidth/2 || getScrollVelocity() > SPPED;
    }
    /**
     * 得到手指滑动速度，每秒移动多少单位像素
     *
     * @return
     */
    private int getScrollVelocity(){
        mVelocityTracker.computeCurrentVelocity(1000);
        int velocity = (int) mVelocityTracker.getXVelocity();
        return Math.abs(velocity);
    }
    /**
     * 显示出menu
     */
    private void scrollToMenu(){
         new ScrollAsyncTask().execute(30);
    }
    /**
     * 隐藏掉menu
     */
    private void scrollToContent(){
         new  ScrollAsyncTask().execute(-30);
    }
    
    /**
     * 回收VelocityTracker对象。
     */
    private void recycleVelocityTrancker(){
        mVelocityTracker.recycle();
        mVelocityTracker = null;
    }
    
    private class ScrollAsyncTask extends AsyncTask<Integer, Integer, Integer>{

        
        @Override
        protected Integer doInBackground(Integer... params) {
            //得到当前的margin
            int leftMargin = mMenuParams.leftMargin;
            //不断更改margin的值
            while(true){
                leftMargin = leftMargin + params[0];
                if(leftMargin > 0){
                    leftMargin = 0;
                    break;
                }
                if(leftMargin < mLeftEdge){
                    leftMargin = mLeftEdge;
                    break;
                }
                publishProgress(leftMargin);
                sleep();
            }
            if(params[0] > 0){
                mIsMenuVisible = true;            
            }else{
                mIsMenuVisible = false;
            }
            return leftMargin;
        }
        
        @Override
        protected void onPostExecute(Integer result) {
            mMenuParams.leftMargin = result;
            mMenuLayout.setLayoutParams(mMenuParams);
        }
        
        @Override
        protected void onProgressUpdate(Integer... values) {
            mMenuParams.leftMargin = values[0];
            mMenuLayout.setLayoutParams(mMenuParams);
        }
        
    }
    
    private void sleep(){
        try {
            Thread.sleep(20);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    
    
}

到此全部结束。

代码改变世界！