实现Android半透明Menu效果的开发实例

不知道大家是否用过天天动听，对于它界面上的半透明Menu效果，笔者感觉非常漂亮。下面是天天动听半透明Menu的截图，欣赏下吧：

感觉还不错吧？那么如何实现这种半透明Menu效果呢？本文就重点讨论并给出这种Menu的具体代码实现过程。

首先分析下实现这种半透明Menu所需做的工作，并进行合理分解：

1. 利用Shaper设置一个半透明圆角背景。

2. 定义Menu布局，主要就GridView，把图标都放在这个GridView。

3. Menu事件, 通过PopupWindow或者AlertDialog或者透明Activity显示到页面即可。

4. 按钮的监听事件，实例中没加。需要的话自己在Adapter里加。

比较简单，不多说了。

半透明圆角背景xml：

package com.yfz;   
      
      
    import android.app.Activity;   
    import android.app.AlertDialog;   
    import android.app.AlertDialog.Builder;   
    import android.content.Context;   
    import android.graphics.drawable.BitmapDrawable;   
    import android.os.Bundle;   
    import android.util.Log;   
    import android.view.ContextMenu;   
    import android.view.Gravity;   
    import android.view.LayoutInflater;   
    import android.view.Menu;   
    import android.view.MenuItem;   
    import android.view.View;   
    import android.view.ViewGroup;   
    import android.view.ContextMenu.ContextMenuInfo;   
    import android.widget.BaseAdapter;   
    import android.widget.GridView;   
    import android.widget.ImageView;   
    import android.widget.LinearLayout;   
    import android.widget.PopupWindow;   
    import android.widget.TextView;   
    import android.widget.LinearLayout.LayoutParams;   
      
    public class MenuTest extends Activity {           
      
            private String TAG = this.getClass().getSimpleName();          
      
            private int[] resArray = new int[] {   
                    R.drawable.icon_menu_addto, R.drawable.icon_menu_audioinfo,   
                    R.drawable.icon_menu_findlrc, R.drawable.icon_menu_scan   
            };           
      
            private String[] title = new String[]{   
                    "添加歌曲", "歌曲信息", "查找歌词", "搜索歌词"  
            };           
      
            private static boolean show_flag = false;           
            private PopupWindow pw = null;           
      
            /** Called when the activity is first created. */  
            @Override  
            public void onCreate(Bundle savedInstanceState) {   
                super.onCreate(savedInstanceState);   
                setContentView(R.layout.main);   
            }   
      
            @Override  
      
            public boolean onCreateOptionsMenu(Menu menu) {   
                    Log.e(TAG, "------  onCreateOptionsMenu ------");   
                    //用AlertDialog弹出menu   
      
    //                View view = LayoutInflater.from(this).inflate(R.layout.menu, null);   
      
    //                GridView grid1 = (GridView)view.findViewById(R.id.menuGridChange);   
      
    //                grid1.setAdapter(new ImageAdapter(this));   
      
    //                Builder build = new AlertDialog.Builder(this);   
      
    //                build.setView(view);   
      
    //                build.show();   
                       
                    LayoutInflater inflater = (LayoutInflater)this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);         
      
                    View view = inflater.inflate(R.layout.menu, null);   
      
                    GridView grid1 = (GridView)view.findViewById(R.id.menuGridChange);   
      
                    grid1.setAdapter(new ImageAdapter(this));                   
      
                    //用Popupwindow弹出menu   
                    pw = new PopupWindow(view,LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);                   
      
                    //NND, 第一个参数， 必须找个View   
                    pw.showAtLocation(findViewById(R.id.tv), Gravity.CENTER, 0, 300);                   
      
                    return true;   
            }   
      
            @Override  
      
            public boolean onOptionsItemSelected(MenuItem item) {   
                    return super.onOptionsItemSelected(item);   
           }   
      
            public class ImageAdapter extends BaseAdapter {                   
                    private Context context;                   
      
                    public ImageAdapter(Context context) {   
                            this.context = context;   
                    }                   
      
                    @Override  
                    public int getCount() {   
                            return resArray.length;   
                    }   
      
                    @Override  
                    public Object getItem(int arg0) {   
                            return resArray[arg0];   
                    }   
      
                    @Override  
                    public long getItemId(int arg0) {   
                            return arg0;   
                    }   
      
                    @Override  
                    public View getView(int arg0, View arg1, ViewGroup arg2) {   
                            LinearLayout linear = new LinearLayout(context);   
      
                            LinearLayout.LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);   
      
                            linear.setOrientation(LinearLayout.VERTICAL);                           
      
                            ImageView iv = new ImageView(context);   
      
                            iv.setImageBitmap(((BitmapDrawable)context.getResources().getDrawable(resArray[arg0])).getBitmap());   
      
                            LinearLayout.LayoutParams params2 = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);   
      
                            params2.gravity=Gravity.CENTER;   
      
                            linear.addView(iv, params2);                           
      
                            TextView tv = new TextView(context);   
      
                            tv.setText(title[arg0]);   
      
                            LinearLayout.LayoutParams params3 = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);   
      
                            params3.gravity=Gravity.CENTER;                           
      
                            linear.addView(tv, params3);                           
                            return linear;   
                    }   
            }   
    }

到此，大家是不是觉得半透明Menu效果也是比较好实现的呢？可以根据自己的需要对此实例进行修改以求更美观好用。