how to use a button to control the popupwindow show or dimiss?
<p>I want use a button to control the popupwindow, When I click the button, the popupwindow showing,and then click the button , the popupwindow dimiss.
The following is my code:</p>

<pre><code>@Override
public void onClick(View v) {
    showPopupWindow();
}

/*** button control the PopupWindow ***/
private void showPopupWindow() {
    View view = View.inflate(this, R.layout.popwindow_item, null);
    popupwindow = new PopupWindow(view, WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.WRAP_CONTENT);
    if (popupwindow.isShowing()) {  
        popupwindow.dismiss();
    }else {
        popupwindow.setOutsideTouchable(true);
        popupwindow.setBackgroundDrawable(new BitmapDrawable());
        popupwindow.showAsDropDown(title);
    }
    viewOfPop(view);
}
</code></pre>

<p>and the result is that when I click the button ,the popupwindow always showing,and won't dimiss.
I also try to use a flag,<code>private boolean isShow = false;</code>,and when I click the button I will change the boolean value,but I don't kown how can I change the boolean value,the popupwindow is close when I click the outside of popupwindow. please help me ,thanks advanced!</p>