/// <summary>
        /// 刷新预览图
        /// 适用于simpleMaker状态
        /// </summary>
        private async Task refreshPreviewAsync()
        {
            //if (simpleMarkerSymbol == null)
            //    return;
            if (simple_RB.Checked)
            {
                if (simpleMarkerSymbol == null)
                {
                    return;
                }
                Esri.ArcGISRuntime.UI.RuntimeImage image = await simpleMarkerSymbol.CreateSwatchAsync(Color.WhiteSmoke);

                System.Windows.Media.ImageSource imageSource = await Esri.ArcGISRuntime.UI.RuntimeImageExtensions.ToImageSourceAsync(image);

                Image result = imageWpfToGDI(imageSource);
                previewBox.Image    = result;
                previewBox.SizeMode = PictureBoxSizeMode.AutoSize | PictureBoxSizeMode.CenterImage;
            }
            else
            {
                if (pictureMarkerSymbol == null)
                {
                    return;
                }
                Esri.ArcGISRuntime.UI.RuntimeImage image = await pictureMarkerSymbol.CreateSwatchAsync(Color.WhiteSmoke);

                System.Windows.Media.ImageSource imageSource = await Esri.ArcGISRuntime.UI.RuntimeImageExtensions.ToImageSourceAsync(image);

                Image result = imageWpfToGDI(imageSource);
                previewBox.Image    = result;
                previewBox.SizeMode = PictureBoxSizeMode.AutoSize | PictureBoxSizeMode.CenterImage;
            }
        }
        /// <summary>
        /// 由传进来的layer初始化simpleMaker的样式
        /// </summary>
        private async void initLegend()
        {
            //初始化点样式
            FeatureLayer   feature        = layer as FeatureLayer;
            SimpleRenderer simpleRenderer = feature.Renderer as SimpleRenderer;

            if (simpleRenderer != null)
            {
                //需要注意的是 这里不应该直接引用传递 否则在未确认的情况下也会影响到点的样式
                simpleMarkerSymbol = simpleRenderer.Symbol.Clone() as SimpleMarkerSymbol;
                //如果为空则说明Symbol不为简单点样式
                if (simpleMarkerSymbol == null)
                {
                    //因为后面需要订阅事件 所以不能为null
                    simpleMarkerSymbol  = new SimpleMarkerSymbol();
                    pictureMarkerSymbol = simpleRenderer.Symbol.Clone() as PictureMarkerSymbol;
                    if (pictureMarkerSymbol != null)
                    {
                        Esri.ArcGISRuntime.UI.RuntimeImage image = await pictureMarkerSymbol.CreateSwatchAsync(Color.WhiteSmoke);

                        System.Windows.Media.ImageSource imageSource = await Esri.ArcGISRuntime.UI.RuntimeImageExtensions.ToImageSourceAsync(image);

                        Image result = imageWpfToGDI(imageSource);
                        previewBox.Image          = result;
                        previewBox.SizeMode       = PictureBoxSizeMode.Zoom;
                        simple_RB.Checked         = false;
                        customPic_RB.Checked      = true;
                        StyleCombox.Enabled       = false;
                        colorBtn.Enabled          = false;
                        sizeUpDown.Value          = (decimal)pictureMarkerSymbol.Width + 1;
                        transparencyControl.Value = MainWindow.getAlpha(pictureMarkerSymbol.Opacity);
                    }
                }
                else
                {
                    int index = findSelectIndex(x =>
                    {
                        return(simpleMarkerSymbol.Style.ToString().Equals(x.ToString()));
                    });
                    int count = ((List <SimpleMarkerSymbolStyle>)StyleCombox.DataSource).Count;
                    //设置传入的layer的样式
                    simple_RB.Checked         = true;
                    StyleCombox.SelectedIndex = index;
                    colorBtn.BackColor        = simpleMarkerSymbol.Color;
                    sizeUpDown.Value          = (decimal)simpleMarkerSymbol.Size;
                    transparencyControl.Value = simpleMarkerSymbol.Color.A;
                    await refreshPreviewAsync();
                }
            }
            //如果Layer是别的数据类型
            else
            {
            }
        }