Android Menu半透明效果的开发实例

<?xml version="1.0" encoding="UTF-8"?>  <shape android:shape="rectangle">    <solid android:color="#b4000000" />   <stroke android:width="2.0dip" android:color="#b4ffffff" android:dashWidth="3.0dip" android:dashGap="0.0dip" />   <padding android:left="7.0dip" android:top="7.0dip" android:right="7.0dip" android:bottom="7.0dip" />   <corners android:radius="8.0dip" />  </shape> 

<?xml version="1.0" encoding="UTF-8"?>  <LinearLayout    android:orientation="vertical"    android:layout_width="wrap_content"    android:layout_height="fill_parent">      <GridView android:gravity="center"      android:layout_gravity="center"      android:id="@+id/menuGridChange"         android:background="@drawable/menu_bg_frame"      android:padding="5.0dip"      android:layout_width="fill_parent"      android:layout_height="wrap_content"      android:horizontalSpacing="10.0dip"      android:verticalSpacing="3.0dip"      android:stretchMode="columnWidth"      android:columnWidth="60.0dip"      android:numColumns="auto_fit"/>       </LinearLayout> 

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;     }   } }