如何在更新或刷新页面后获取选定的下拉值

Question

如何在更新或刷新页面后获取所选下拉值，如果我在刷新页面后更新所选下拉值，则下拉值将在之前更新

- (BOOL)isGoogleMapMarkerVisible:(GMSMarker*)marker {

    //Marker point
    CGPoint markerpoint = [self.mapview.projection pointForCoordinate:marker.position];

    //Maximum visible region from x and y axis
    float x = 0.0;
    float y = o.o;
    float maxX = self.mapview.frame.size.width;
    float maxY = self.mapview.frame.size.height;

    //If marker point is on visible region return true else return false
    if (markerpoint.x > x && markerpoint.y > y && markerpoint.x < maxX && markerpoint.y < maxY) {
        return YES;
    }
    else {
            return NO;
    }
}

如何在更新或刷新页面后获取所选的下拉值，如果我在刷新页面后更新选定的下拉值，则下拉值将在前一个更新

<div class="form-group">
    <label class="sr-only" for="ParkName">Park Name</label>
    <input type="text" class="form-control" name="ParkName"  placeholder="Park Name" id="park_name"/>
    <input type="hidden" name="ParkName" value="'*'" id="park_name"/>
</div>