Obtains a reference to a client-side function that, when invoked, initiates a client call back to a server-side event that is handled by the Chart.
Obtains a reference to a client-side function that, when invoked, initiates a client call back to a server-side event which is handled by the Chart. The browser event bubbling will be canceled.
Syntax
| Visual Basic (Usage) |
 Copy Code |
Dim instance As ChartCallbackManager
Dim command As String
Dim arguments As String
Dim value As String
value = instance.GetCallbackEventReference(command, arguments)
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Parameters
- command
- The control that handles the arguments.
The control which handles the arguments
- arguments
- String which is passed to the target control.
String which is passed to the targetControl
Return Value
String that represents a javascript function.
String which represents javascript function.
Example
This example demonstrates how to use the
Callback event to explode a pie slice when that slice is clicked. We assume a chart has been added at design-time.
| Visual Basic |
Copy Code |
Imports Dundas.Charting.WebControl
...
Protected Sub Page_Load(sender As Object, e As EventArgs)
If Not IsPostBack Then
Chart1.Series(0).Points.Clear()
Chart1.Series(0).Points.AddXY(1, 4)
Chart1.Series(0).Points.AddXY(2, 5)
Chart1.Series(0).Points.AddXY(3, 2)
Chart1.Series(0).Points.AddXY(4, 1)
End If
Chart1.Series(0).MapAreaAttributes = "onclick=""" +
Chart1.CallbackManager.GetCallbackEventReference("PieClick", "#INDEX") + """"
End Sub
Protected Sub Chart1_Callback(sender As Object, e As CommandEventArgs)
If e.CommandName = "PieClick" Then
Dim point As DataPoint
For Each point In Chart1.Series(0).Points
point("Exploded") = "False"
Next point
Dim index As Integer = Integer.Parse(e.CommandArgument.ToString())
Chart1.Series(0).Points(index)("Exploded") = "True"
End If
End Sub
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| C# |
Copy Code |
using Dundas.Charting.WebControl
...
// Page Load event handler.
protected void Page_Load(object sender, EventArgs e)
{
// We add points to the chart only when the page is first rendered.
if (!IsPostBack)
{
Chart1.Series[0].Points.Clear();
Chart1.Series[0].Points.AddXY(1, 4);
Chart1.Series[0].Points.AddXY(2, 5);
Chart1.Series[0].Points.AddXY(3, 2);
Chart1.Series[0].Points.AddXY(4, 1);
}
// Use GetCallbackEventReference method to create Javascript.
// We use chart keyword #INDEX as a parameter for the Callback event.
Chart1.Series[0].MapAreaAttributes = "onclick=\"" +
Chart1.CallbackManager.GetCallbackEventReference("PieClick", "#INDEX") + "\"";
}
// Chart Callback event handler.
protected void Chart1_Callback(object sender, CommandEventArgs e)
{
if (e.CommandName == "PieClick")
{
// Reset pie chart so that no pie slices are exploded.
foreach (DataPoint point in Chart1.Series[0].Points)
point["Exploded"] = "False";
// Explode the correct pie slice.
int index = int.Parse(e.CommandArgument.ToString());
Chart1.Series[0].Points[index]["Exploded"] = "True";
}
}
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Requirements
Target Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, Windows Vista, Windows Server 2008 family
See Also
