popwindow

 View view=LayoutInflater.from(this).inflate(R.layout.clean_pop, null);
// popupWindow = new PopupWindow(view, 300, 200);
 popupWindow = new PopupWindow(view,  ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, false);
 // 需要设置一下此参数，点击外边可消失
 popupWindow.setBackgroundDrawable(new BitmapDrawable());
 //设置点击窗口外边窗口消失
 popupWindow.setOutsideTouchable(true);
 // 设置此参数获得焦点，否则无法点击
 popupWindow.setFocusable(true);
 if(popupWindow.isShowing()) {
     // 隐藏窗口，如果设置了点击窗口外小时即不需要此方式隐藏
     popupWindow.dismiss();
 } else {
     // 显示窗口
    // popupWindow.isShowing();
     popupWindow.showAtLocation(v, Gravity.CENTER, 0, 0);
     darkenBackground(0.2f);
 }
 popupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {

     @Override
     public void onDismiss() {
         darkenBackground(1f);
     }
 });
//____________________________

/**
 * 改变背景颜色
 */
private void darkenBackground(Float bgcolor){
    WindowManager.LayoutParams lp = getWindow().getAttributes();
    lp.alpha = bgcolor;

    getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
    getWindow().setAttributes(lp);

}