MapView annotation view
<p>i need to change the view of annotation after each 20 second how can i do it</p>

<pre><code>for (int i = 0; i &lt; [_shadowArray count]; i++)
{
    Shadows* shadowObj1;

    shadowObj1 = [_shadowArray objectAtIndex:i];
    CLLocationCoordinate2D location1;   

    location1.latitude =  [shadowObj1.position_x floatValue];
    location1.longitude = [shadowObj1.position_y floatValue];   

    annotaionObj = [[AnnotationDelegate alloc] initWithCoordinate:location1 name:@"" sub:@"Catch me! "];
    [_annotationArray addObject:annotaionObj];
    [_mapView     addAnnotation:annotaionObj];

}
</code></pre>
