This example uses the Paint method to add a drop-down box to DataGrid1
1. Create a new Visual Basic Project. 2, add a DataGrid Control to the form. 3, add the following code
Imports system.data.sqlclient
Public Class Form1
Inherits System.Windows.Forms.form
#Region "Windows Form Designer Generated Code"
Public Sub New ()
Mybase.new ()
'This call is required for the Windows Form Designer.
InitializeComponent ()
'Add any initialization after INITIALIZECOMPONENT ()
End Sub
'Form rewriting disposal to clean the component list.
Protected Overloads Overrides Sub Dispose (Byval Disposing as Boolean)
IF Disposing then
IF not (Components Is Nothing) THEN
Components.dispose ()
END IF
END IF
Mybase.dispose (Disposing)
End Sub
'Windows Form Designer
Private Components as System.comPonentModel.icontainer
'Note: The following process is necessary for the Windows Form Designer.
'You can modify this process using the Windows Form Designer.
'Don't modify it using the code editor.
Friend Withevents DataGrid1 As System.Windows.Forms.DataGrid
Me.DataGrid1 = new system.windows.Forms.DataGrid ()
Ctype (me.datagrid1, system.componentmodel.isupportinitialize) .beginInit ()
Me.suspendlayout ()
'
'DataGrid1
'
Me.DataGrid1.datamember = ""
Me.DataGrid1.HeaderforeColor = system.drawing.systemcolors.ControlText
Me.DataGrid1.location = new system.drawing.point (72, 56)
Me.DataGrid1.name = "DataGrid1"
Me.DataGrid1.size = new system.drawing.size (416, 184)
Me.DataGrid1.tabindex = 0
'
'Form1
'
Me.autoscalebasesize = new system.drawing.size (6, 14)
Me.ClientSize = new system.drawing.size (552, 285)
Me.Controls.addrange (new system.windows.forms.control () {me.datagrid1})
Me.Name = "Form1"
Me.Text = "Form1"
Ctype (me.datagrid1, system.componentmodel.isupportinitialize) .endinit ()
Me.ResumeLayout (false) End Sub
#End region
Public myCombo as new comboBox ()
DIM Con As New SqlConnection ("Server = LiHG; UID = SA; PWD = SA; Database = Northwind")
Dim Daemp As New SqldataAdapter ("Select * from Employees", CON)
Public DS as new dataset ()
Private Sub Form1_Load (Byval E AS System.Object, Byval E AS System.Eventargs) Handles MyBase.LOAD
AddHandler mycombo.textchanged, addressof ctrls_textchanged
'Fill ComboBox List.
Mycombo.name = "mycombo"
Mycombo.visible = false
Mycombo.items.clear ()
Mycombo.items.add ("Sales Repesentative")
Mycombo.items.add ("INSIDE SALES COORDINATOR")
Mycombo.items.add ("Vice PRESIDENT, SALES")
Mycombo.items.add ("Sales Manager")
Mycombo.items.add ("flunky")
Daemp.Fill (DS, "Employees")
'Set the rowheight of the datagrid to the height of the comboBox.
DataGrid1.preferredRowheight = mycombo.height
DataGrid1.datasource = DS
DataGrid1.DataMember = "Employees"
'Add ComboBox To The Control Collection of The DataGrid.
DataGrid1.controls.add (MyCombo)
End Sub
Private sub DataGrid1_paint (Byval e as system.windows.forms.painteventargs) Handles DataGrid1.paint
If DataGrid1.currentcell.columnNumber = 3 THEN
Mycombo.Width = DataGrid1.getcurrentcellbounds.width
END IF
End Sub
Private sub ctrls_textchanged (Byval E AS Object, ByVal E AS System.EventArgs)
If DataGrid1.currentcell.columnNumber = 3 THEN
Mycombo.visible = false
If DataGrid1.item (DataGrid1.currentcell & "=" "THEN
SendKeys.send ("*")
END IF
DataGrid1.item (DataGrid1.currentcell = mycombo.text
END IF
End Sub
Private sub DataGrid1_currentcellchanged (Byval e as system.eventargs) Handles DataGrid1.currentCellChanged
If DataGrid1.currentcell.columnNumber = 3 THEN
Mycombo.visible = false
Mycombo.width = 0
Mycombo.left = DataGrid1.getCurrentcellbounds.Left
Mycombo.top = DataGrid1.getcurrentcellbounds.top
Mycombo.text = DataGrid1.item (DataGrid1.currentcell) & ""
Mycombo.visible = true
Else
Mycombo.visible = false
Mycombo.width = 0
END IF
End Sub
Private sub DataGrid1_scroll (Byval e as system.eventargs) Handles DataGrid1.Scroll
Mycombo.visible = false
Mycombo.width = 0
End Sub
Private sub DataGrid1_click (Byval e as system.eventargs) Handles DataGrid1.click
Mycombo.visible = false
Mycombo.width = 0
End Sub
END CLASS
4, repair string DIM Con As new SqlConnection ("server = lihg; uid = sa; pwd = sa; database = northwind"), enable connection to database 5, F5 operation
