安卓音乐播放器--侧边栏

侧边栏学习

参考资料：http://www.chinatarena.com/Html/adpeixun/201307/5251.html

还有一个参考的代码 最后自己的理解是 在scrollView中添加两个水平的视图 

		musicListLayout.findViewById(R.id.btnMusicListSlide).setOnClickListener(new MusicListActivity.ClickListenerForScrolling(scrollView, menu));
		final View[] children=new View[]{menuLayout,musicListLayout};
		int scrollToViewIdx=0;
		scrollView.initViews(children, scrollToViewIdx, new MusicListActivity.SizeCallbackForMenu(musicListLayout.findViewById(R.id.btnMusicListSlide))

之前使用一个透明的TextView替代menuLayout 之前的menuLayout如下：

    
    
        
        
    


    This HorizontalScrollView will contain a LinearLayout that will contain a transparent
    View (that allows the menu above to show through) and the other application Views.
  
    

        
 
        

    

采用帧布局 在菜单滑出时透明层将app“挤”过去一些 由于是帧布局 其上是透明层 于是就把底下的menu显示出来（网上下载的demo）后想改成右边的菜单栏 无法实现 每次都会显示成菜单的后半段 如图

之前没太明白为什么 后来想 这样透明层是推开了 但是底下的还是没变 所以会这样吧 于是后来不用透明层 直接用menuLayout 作为children 但是会报错 

意思是它已经有了一个父节点 然后将menuLayout中的MyHorizontalScrollView单独写成一个xml 然后在setContentView时设置为MyHorizontalScrollView 在MyHorizontalScrollView代码中更改了onGlobalLayout中添加children的顺序 于是就能从右边滑出 至于为什么 我可以说是一种直觉么。。 哈哈 下面贴上MyHorizontalScrollView 的代码（其实百度一下有超多的）

/*
 * #%L
 * SlidingMenuDemo
 * $Id:$
 * $HeadURL:$
 * %%
 * Copyright (C) 2012 Paul Grime
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package com.vanhon.mediaplayer2.view;

import android.content.Context;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.HorizontalScrollView;

/**
 * A HorizontalScrollView (HSV) implementation that disallows touch events (so no scrolling can be done by the user).
 * 
 * This HSV MUST contain a single ViewGroup as its only child, and this ViewGroup will be used to display the children Views
 * passed in to the initViews() method.
 */
public class MyHorizontalScrollView extends HorizontalScrollView {
    public MyHorizontalScrollView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context);
    }

    public MyHorizontalScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public MyHorizontalScrollView(Context context) {
        super(context);
        init(context);
    }

    void init(Context context) {
        // remove the fading as the HSV looks better without it
        setHorizontalFadingEdgeEnabled(false);
        setVerticalFadingEdgeEnabled(false);
    }

    /**
     * @param children
     *            The child Views to add to parent.
     * @param scrollToViewIdx
     *            The index of the View to scroll to after initialisation.
     * @param sizeCallback
     *            A SizeCallback to interact with the HSV.
     */
    public void initViews(View[] children, int scrollToViewIdx, SizeCallback sizeCallback) {
        // A ViewGroup MUST be the only child of the HSV
        ViewGroup parent = (ViewGroup) getChildAt(0);

        // Add all the children, but add them invisible so that the layouts are calculated, but you can't see the Views
        for (int i = 0; i