xamarin forms 下 ImageButton 点击

需求是：一个button，四种状态
如有更好实现，烦劳转告。

以下实现或许有些伪，用了Pressed="btnclicked"
而不是Clicked="btnclicked"，但是效果还是可以的。
用图如下，动图脑补：

主要代码一：

<ImageButton x:Name="testIMBTN"  WidthRequest="50" HeightRequest="50" Pressed="btnclicked" Source="" BackgroundColor="Transparent"  
                        VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" >

                <VisualStateManager.VisualStateGroups>
                    <VisualStateGroup x:Name="StateGroup">
                        <VisualState x:Name="Normal">
                            <VisualState.Setters>
                                <Setter Property="Scale" Value="1" />
                               
                                <Setter Property="Source" Value="{local:ImageResource  xxxxelapse.Shared.images.pause.png}" />
                            </VisualState.Setters>
                        </VisualState>
                        <VisualState x:Name="Pressed">
                            <VisualState.Setters>
                                <Setter Property="Scale" Value="1" />
                                
                                <Setter Property="Source" Value="{local:ImageResource  xxxxxelapse.Shared.images.pause_pressed.png}" />
                            </VisualState.Setters>
                        </VisualState>
                    </VisualStateGroup>
                </VisualStateManager.VisualStateGroups>
            </ImageButton>

主要代碼二：

        int flag = 0;
        private async void btnclicked(object sender, EventArgs e)
        {
           
            var visualStateGroups = VisualStateManager.GetVisualStateGroups(testIMBTN);

            foreach (VisualStateGroup vsg in visualStateGroups)
            {
                foreach (VisualState vs in vsg.States)
                {
                    if (vs.Name == "Normal")
                    {
                        foreach(Setter setter in vs.Setters)
                        {
                            if(setter.Property.PropertyName == "Source")
                            {
                                if(flag == 0)
                                  setter.Value = ImageSource.FromResource("xxxelapse.Shared.images.play.png", typeof(Page2).Assembly);
                                else
                                  setter.Value = ImageSource.FromResource("xxxelapse.Shared.images.pause.png", typeof(Page2).Assembly);
                            }                           
                        }
                    }
                    if (vs.Name == "Pressed")

                    {
                        foreach (Setter setter in vs.Setters)
                        {
                            if (setter.Property.PropertyName == "Source")
                            {
                                if (flag == 0)
                                    setter.Value = ImageSource.FromResource("xxxlapse.Shared.images.play_pressed.png", typeof(Page2).Assembly);
                                else
                                    setter.Value = ImageSource.FromResource("xxxelapse.Shared.images.pause_pressed.png", typeof(Page2).Assembly);
                            }
                        }
                    }
                }
            }

            if (flag == 0)
                flag = 1;
            else
                flag = 0;
        }