Archives: FAQs

Holds Syncfusion FAQs and specific data

How do I determine the DataGridTableStyle MappingName that should used for a DataGrid to make sure the grid uses my tablestyle

The DataGrid looks for a DataGridTableStyle.MappingName that is the type name of its datasource. So, depending upon what datasource you are using, this may be ‘ArrayList’ for a ArrayList, ‘MyCollection[]’ for an array of MyCollection objects, or ‘MyTableName’ for a datatable, or whatever. Here is a code snippet provide by NoiseEHC on the microsoft.public.dotnet.framework.windowsforms.controls newsgroup that you can use to see exactly what mappingname is required for your datasource. [C#] //usage ShowMappingName(dataGrid1.DataSource); //implementation void ShowMappingName(object src) { IList list = null; Type type = null; if(src is Array) { type = src.GetType(); list = src as IList; } else { if(src is IListSource) src = (src as IListSource).GetList(); if(src is IList) { type = src.GetType(); list = src as IList; } else { MessageBox.Show(‘error’); return; } } if(list is ITypedList) MessageBox.Show((list as ITypedList).GetListName(null)); else MessageBox.Show(type.Name); } [VB.NET] Private Sub ShowMappingName(ByVal src As Object) Dim list As IList = Nothing Dim t As Type = Nothing If TypeOf (src) Is Array Then t = src.GetType() list = CType(src, IList) Else If TypeOf src Is IListSource Then src = CType(src, IListSource).GetList() End If If TypeOf src Is IList Then t = src.GetType() list = CType(src, IList) Else MessageBox.Show(‘Error’) Return End If End If If TypeOf list Is ITypedList Then MessageBox.Show(CType(list, ITypedList).GetListName(Nothing)) Else MessageBox.Show(t.Name) End If End Sub

How can I catch an exception on a program wide basis

You can handle the Application.ThreadException event. See the FrameWork class library for a more detailed sample in both VB and C#. [STAThread] public static void Main() { Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(UnhandledExceptionCatcher); Application.Run(new Form1()); } private static void UnhandledExceptionCatcher(object sender, System.Threading.ThreadExceptionEventArgs e) { Console.WriteLine(‘caught an unhandled exception.’); }

How can I get a tooltip to vary from node to node in my treeview

Try using a MouseMove event handler and checking to see if you have moved to a new node, and if so, set a new tiptext. [C#] private int oldNodeIndex = -1; private ToolTip toolTip1; private void Form1_Load(object sender, System.EventArgs e) { this.toolTip1 = new System.Windows.Forms.ToolTip(); this.toolTip1.InitialDelay = 300; //half a second delay this.toolTip1.ReshowDelay = 0; } private void treeView1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e) { TreeNode tn = this.treeView1.GetNodeAt(e.X, e.Y); if(tn != null) { int currentNodeIndex = tn.Index; if(currentNodeIndex != oldNodeIndex) { oldNodeIndex = currentNodeIndex; if(this.toolTip1 != null && this.toolTip1.Active) this.toolTip1.Active = false; //turn it off this.toolTip1.SetToolTip(this.treeView1, string.Format(‘tooltip: node {0}’, oldNodeIndex)); this.toolTip1.Active = true; //make it active so it can show } } } [VB.NET] Private oldNodeIndex As Integer = – 1 Private toolTip1 As ToolTip Private Sub Form1_Load(sender As Object, e As System.EventArgs) Me.toolTip1 = New System.Windows.Forms.ToolTip() Me.toolTip1.InitialDelay = 300 ’half a second delay Me.toolTip1.ReshowDelay = 0 End Sub ’Form1_Load Private Sub treeView1_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) Dim tn As TreeNode = Me.treeView1.GetNodeAt(e.X, e.Y) If Not (tn Is Nothing) Then Dim currentNodeIndex As Integer = tn.Index If currentNodeIndex <> oldNodeIndex Then oldNodeIndex = currentNodeIndex If Not (Me.toolTip1 Is Nothing) And Me.toolTip1.Active Then Me.toolTip1.Active = False ’turn it off End If Me.toolTip1.SetToolTip(Me.treeView1, String.Format(‘tooltip: node {0}’, oldNodeIndex)) Me.toolTip1.Active = True ’make it active so it can show End If End If End Sub ’treeView1_MouseMove