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：

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent"    android:layout_height="fill_parent" android:background="#00ffffff" android:padding="0px" android:layout_margin="0px">    <!--    This ImageView is used as a menu.    --><!--     <ImageView android:id="@+id/menu" android:src="@drawable/fb_menu" android:layout_width="fill_parent"        android:layout_height="fill_parent" android:scaleType="fitStart" />         -->    <LinearLayout         android:id="@+id/menu"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:orientation="vertical"        android:layout_gravity="right"        >        <Button             android:id="@+id/playMode"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="测试"            />        <Button             android:id="@+id/btnExit"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="退出"            />    </LinearLayout>    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.      <com.vanhon.mediaplayer2.view.MyHorizontalScrollView android:id="@+id/myScrollView"        android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#00ffffff" android:padding="0px"        android:layout_margin="0px" android:fadingEdge="none" android:fadingEdgeLength="0px" android:scrollbars="none">        <LinearLayout android:id="@+id/top" android:layout_height="fill_parent" android:layout_width="fill_parent"            android:orientation="horizontal" android:background="#00ffffff" android:padding="0px" android:layout_margin="0px">         </LinearLayout>    </com.vanhon.mediaplayer2.view.MyHorizontalScrollView></FrameLayout>

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 <children.length ; i++) {            children[i].setVisibility(View.INVISIBLE);            parent.addView(children[i]);        }        // Add a layout listener to this HSV        // This listener is responsible for arranging the child views.        OnGlobalLayoutListener listener = new MyOnGlobalLayoutListener(parent, children, scrollToViewIdx, sizeCallback);        getViewTreeObserver().addOnGlobalLayoutListener(listener);//        System.out.println("initViews完毕");    }    @Override    public boolean onTouchEvent(MotionEvent ev) {        // Do not allow touch events.        return false;    }    @Override    public boolean onInterceptTouchEvent(MotionEvent ev) {        // Do not allow touch events.        return false;    }    /**     * An OnGlobalLayoutListener impl that passes on the call to onGlobalLayout to a SizeCallback, before removing all the Views     * in the HSV and adding them again with calculated widths and heights.     */    class MyOnGlobalLayoutListener implements OnGlobalLayoutListener {        ViewGroup parent;        View[] children;        int scrollToViewIdx;        int scrollToViewPos = 0;        SizeCallback sizeCallback;        /**         * @param parent         *            The parent to which the child Views should be added.         * @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 MyOnGlobalLayoutListener(ViewGroup parent, View[] children, int scrollToViewIdx, SizeCallback sizeCallback) {            this.parent = parent;            this.children = children;            this.scrollToViewIdx = scrollToViewIdx;            this.sizeCallback = sizeCallback;        }        @Override        public void onGlobalLayout() {             System.out.println("onGlobalLayout");            final HorizontalScrollView me = MyHorizontalScrollView.this;            // The listener will remove itself as a layout listener to the HSV            me.getViewTreeObserver().removeGlobalOnLayoutListener(this);            // Allow the SizeCallback to 'see' the Views before we remove them and re-add them.            // This lets the SizeCallback prepare View sizes, ahead of calls to SizeCallback.getViewSize().            sizeCallback.onGlobalLayout();            parent.removeViewsInLayout(0, children.length);            final int w = me.getMeasuredWidth();            final int h = me.getMeasuredHeight();            // System.out.println("w=" + w + ", h=" + h);            // Add each view in turn, and apply the width and height returned by the SizeCallback.            int[] dims = new int[2];            scrollToViewPos = 0;//            for (int i = 0; i <children.length; i++) {            for (int i = children.length-1; i >=0; i--) {                sizeCallback.getViewSize(i, w, h, dims);//                 System.out.println("addView w=" + dims[0] + ", h=" + dims[1]+",i="+i);                children[i].setVisibility(View.VISIBLE);                parent.addView(children[i], dims[0], dims[1]);                if (i < scrollToViewIdx) {                    scrollToViewPos += dims[0];                }            }            // For some reason we need to post this action, rather than call immediately.            // If we try immediately, it will not scroll.            new Handler().post(new Runnable() {                @Override                public void run() {                    me.scrollBy(scrollToViewPos, 0);                }            });        }    }    /**     * Callback interface to interact with the HSV.     */    public interface SizeCallback {        /**         * Used to allow clients to measure Views before re-adding them.         */        public void onGlobalLayout();        /**         * Used by clients to specify the View dimensions.         *          * @param idx         *            Index of the View.         * @param w         *            Width of the parent View.         * @param h         *            Height of the parent View.         * @param dims         *            dims[0] should be set to View width. dims[1] should be set to View height.         */        public void getViewSize(int idx, int w, int h, int[] dims);    }}

最后的效果图：