how to make animation for popup window in android
<p>I hava a popup window in my application, its appears when some button clicked
I want to set fade in animation to this window,
I put the xml file in "res/anim" folder and set the animation style for the popup window but the animation does not work? 
here is my codes:</p>

<p>myanim.xml...</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;set xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;alpha android:fromAlpha="0.0"
        android:toAlpha="1.0" 
        android:interpolator="@android:anim/accelerate_interpolator" 
        android:duration="4000"
        android:repeatCount="1"/&gt;
&lt;/set&gt;
</code></pre>

<p>===============================================</p>

<p>Create the popup window</p>

<pre><code>private PopupWindow showOptions(Context mcon){
    try{ 
        LayoutInflater inflater = (LayoutInflater) mcon.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        View layout = inflater.inflate(R.layout.options_layout,null);
        layout.setAnimation(AnimationUtils.loadAnimation(this, R.anim.myanim));
        PopupWindow optionspu = new PopupWindow(layout, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

        optionspu.setFocusable(true);
        optionspu.showAtLocation(layout, Gravity.TOP, 0, 0);
        optionspu.update(0, 0, LayoutParams.WRAP_CONTENT, (int)(hei/5));
        optionspu.setAnimationStyle(R.anim.myanim);
        return optionspu;
    }
    catch (Exception e){e.printStackTrace();
    return null;}
}
</code></pre>

<p>=================================================
onClick method... (optionsPopup is global variable of type PopupWindow)</p>

<pre><code> @Override
public void onClick(View v) {
               switch (v.getId()) { 
        case R.id.options:
                optionsPopup=showOptions(this);
            break;  
}
</code></pre>
