Added new kb article htmlchart-customize-legend-dash-type (#600)

Co-authored-by: KB Bot <[email protected]>

Author: github-actions[bot]

knowledge-base/htmlchart-customize-legend-dash-type.md

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+---
+title: Customizing Legend Dash Type in RadHtmlChart
+description: Learn how to modify the legend item's dash type in RadHtmlChart to match the dash style of its corresponding series.
+type: how-to
+page_title: How to Customize Legend Dash Type in RadHtmlChart for ASP.NET AJAX
+slug: htmlchart-customize-legend-dash-type
+tags: radhtmlchart, asp.net ajax, legend, dash type, visualization
+res_type: kb
+ticketid: 1666132
+---
+
+## Environment
+
+<table>
+<tbody>
+<tr>
+<td>Product</td>
+<td>RadHtmlChart for ASP.NET AJAX</td>
+</tr>
+<tr>
+<td>Version</td>
+<td>All</td>
+</tr>
+</tbody>
+</table>
+
+## Description
+
+When using a RadHtmlChart with a line series displayed as a dashed line, the default behavior shows the legend item as a solid line. The goal is to make the legend item appear with a dash type matching its corresponding series.
+
+This KB article also answers the following questions:
+- How can I change the appearance of legend items in RadHtmlChart?
+- Is it possible to apply custom styles to legend items based on the series style?
+- Can I use a custom visual to modify legend items in RadHtmlChart?
+
+## Solution
+
+To customize the dash type of a legend item in RadHtmlChart, use a custom visual function. This approach allows the legend item to reflect the same dash type as its corresponding series item.
+
+1. Define the RadHtmlChart control with the necessary series and specify the `DashType` for each series.
+
+2. Use the `Visual` property of the `Legend` > `Item` to assign a JavaScript function that customizes the appearance of the legend item.
+
+3. Implement the custom visual function (`legendItemVisual`) to create a legend item with a dashed line matching the series dash type.
+
+Here's a code snippet demonstrating this solution:
+
+````ASP.NET
+<telerik:RadHtmlChart runat="server" ID="RadHtmlChart1" Height="400px">
+    <Legend>
+        <Appearance Position="Bottom" />
+        <Item Visual="legendItemVisual" />
+    </Legend>
+    <PlotArea>
+        <Series>
+            <telerik:LineSeries Name="Actual">
+                <LineAppearance DashType="Dash" />
+                <SeriesItems>
+                    <telerik:CategorySeriesItem Y="190000" />
+                    <telerik:CategorySeriesItem Y="25000" />
+                    <telerik:CategorySeriesItem Y="175000" />
+                </SeriesItems>
+            </telerik:LineSeries>
+            <!-- Include other series as needed -->
+        </Series>
+    </PlotArea>
+    <ChartTitle Text="Product Sales for 2014">
+    </ChartTitle>
+</telerik:RadHtmlChart>
+````
+
+4. Define the `legendItemVisual` JavaScript function to adjust the legend's item appearance.
+
+````JavaScript
+legendItemVisual = function (e) {
+    var color = e.options.markers.background;
+    var labelColor = e.options.labels.color ? e.options.labels.color : "#000";
+    var rect = new kendo.geometry.Rect([0, 0], [200, 50]);
+    var layout = new kendo.drawing.Layout(rect, {
+        spacing: 5,
+        alignItems: "center"
+    });
+
+    var marker = new kendo.drawing.Path({
+        stroke: {
+            color: color,
+            width: 3,
+            dashType: e.series.dashType
+        }
+    }).moveTo(0, 0).lineTo(30, 0);
+
+    var label = new kendo.drawing.Text(e.series.name, [0, 0], {
+        fill: {
+            color: labelColor
+        }
+    });
+
+    layout.append(marker, label);
+    layout.reflow();
+
+    return layout;
+};
+````
+
+Adopting this approach allows for a consistent visual representation between the series and their corresponding legend items.
+
+## See Also
+
+- [Visual Template in RadHtmlChart Documentation](https://docs.telerik.com/devtools/aspnet-ajax/controls/htmlchart/functionality/visual-template#visual-template)
+- [RadHtmlChart Overview](https://docs.telerik.com/devtools/aspnet-ajax/controls/htmlchart/overview)