VB.NET DataGridView

Use DataGridView from Windows Forms. Add event handlers and access properties.

DataGridView provides a visual interface to data. It is an excellent way to display and allow editing for your data. It is accessed with VB.NET code. Data edited in the DataGridView can then be persisted in the database.

Example. First, you should add a DataGridView control to your Windows Forms application by double-clicking on the control name in the Visual Studio designer panel. After you add the control, you can add the Load event on the form.

Load: You can create the Load event on the Form's event pane in Visual Studio. We use Load in this example.

Here: We use an empty DataTable on the DataGridView control. We assign the DataSource property.

VB.NET program that uses DataGridView Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles MyBase.Load ' ' Fill in the data grid on form load. ' DataGridView1.DataSource = GetDataTable() End Sub Private Function GetDataTable() As DataTable ' ' This Function needs to build the data table. ' Return New DataTable() End Function End Class

Notes, program. The event handler is executed when the program starts up and when the DataGridView control is displayed. The Form1_Load sub calls into the GetDataTable function, which would return a DataTable from your database in SQL Server.

Info: Assigning the DataSource property copies no data. The DataGridView reads in the DataTable and displays all its contents on the screen in grid form.

DataTable

Lightning bolt. When using the DataGridView control in Windows Forms, you should use the lightning bolt panel. This allows you to manipulate the events on the control. DataGridView has many events, and this article doesn't describe them all.

However: You will often want the CellClick, SelectionChanged, CellDoubleClick, and KeyPress events, depending on your requirements.

Objects. You can use an object collection, such as a List(Of String), in your DataGridView using the Visual Basic language. The object collection will be read. Its properties (get accessors) will be used to display the values on the screen.List

Tip: This is the easiest way to get started with DataGridView. But it may be less effective than more complex approaches.

Test: The program includes the Public Class Test definition, which encapsulates two properties with backing stores (Name and Cost).

Note: It is important to declare the members as properties so the metadata can be used by the DataGridView.

And: Two new Test objects are added to the List. These 2 objects are reflected in the DataGridView output to the screen.

Class used in program: VB.NET ''' <summary> ''' This class contains two properties. ''' </summary> Public Class Test Public Sub New(ByVal name As String, ByVal cost As String) _name = name _cost = cost End Sub Private _name As String Public Property Name() As String Get Return _name End Get Set(ByVal value As String) _name = value End Set End Property Private _cost As String Public Property Cost() As String Get Return _cost End Get Set(ByVal value As String) _cost = value End Set End Property End Class VB.NET program that uses DataGridView with class Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles MyBase.Load ' ' Fill in the data grid with a List ' Dim list = New List(Of Test) list.Add(New Test("Mac", 2200)) list.Add(New Test("PC", 1100)) DataGridView1.DataSource = list End Sub End Class

Hide row headers. You can hide the row headers, which are the boxes on the left of the DataGridView control, from appearing on the screen. The screenshot shows what the row headers look like on DataGridView controls.

Tip: Go to the Visual Studio designer and change the value of RowHeadersVisible to false. This hides row headers.

Improve tabbing. It is possible to improve the behavior for tabbing into and out of the DataGridView control in your Windows Forms program. You can change the StandardTab property on the control in the Visual Studio designer.

So: When StandardTab is enabled, the focus will move out of the DataGridView control when the user presses tab.

Add rows. We can manually add rows to the DataGridView control. The Rows.Add function will return the index of the newly-added row. After calling Rows.Add, you can use the Item accessor and the column index to assign the Value properly.

Here: The example adds a row with two strings to the DataGridView on load. These are displayed to the screen.

VB.NET program that adds rows Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles MyBase.Load ' Add row using the Add subroutine. Dim n As Integer = DataGridView1.Rows.Add() DataGridView1.Rows.Item(n).Cells(0).Value = "First" DataGridView1.Rows.Item(n).Cells(1).Value = "Second" End Sub End Class

Adding columns in designer first. The example throws an exception if you do not have at least two columns in the DataGridView. To add columns to the control, you can use the Columns collection in the designer and use the Add button.

Then: After you add the columns, compile and run your program and no exception will be thrown.

Edit Columns

Get current cell. We can obtain the location of the current cell in VB.NET code. One way you can do this is add the SelectionChanged event. As a reminder, you can add events easily in Visual Studio by using the lightning bolt panel.

Next: In the DataGridView1_SelectionChanged event, you can access the DataGridView1.CurrentCellAddress property.

CurrentCellAddress: This is a System.Drawing.Point type that has two instance properties, X and Y.

Tip: You can use the Point itself or just access its properties. Its properties are of type Integer.

SelectionChanged: This signals when the user changes the current cell or clicks on any cell.

VB.NET program that gets current cell Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles MyBase.Load ' Uses Test class from above. Dim list = New List(Of Test) list.Add(New Test("Mac", 2200)) list.Add(New Test("PC", 1100)) DataGridView1.DataSource = list End Sub Private Sub DataGridView1_SelectionChanged(ByVal sender As System.Object, _ ByVal e As System.EventArgs) _ Handles DataGridView1.SelectionChanged ' Get the current cell location. Dim y As Integer = DataGridView1.CurrentCellAddress.Y Dim x As Integer = DataGridView1.CurrentCellAddress.X ' Write coordinates to console. Console.WriteLine(y.ToString + " " + x.ToString) End Sub End Class

Expand cells. It is possible to make the cells in a DataGridView expand horizontally. You can set the AutoSizeColumnsMode to fill. Also, you can weight certain columns to have larger widths than other columns using the Edit Columns dialog box.

Double-clicking. You can handle the events that occur when the user double-clicks on a cell. You can open the Visual Studio designer and add the CellDoubleClick event in the pane with the lightning bolt.

Note: When the CellDoubleClick event occurs and the header was clicked on, the RowIndex of the DataGridViewCellEventArgs parameter is -1.

VB.NET program that uses double-clicking Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles MyBase.Load ' Load here. End Sub Private Sub DataGridView1_CellDoubleClick(ByVal sender As System.Object, _ ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) _ Handles DataGridView1.CellDoubleClick If e.RowIndex = -1 Then Return End If ' Double-click logic. End Sub End Class

Summary. We looked at the DataGridView control in the VB.NET language targeting the .NET Framework. This control is ideal for rendering data to the screen in programs that use collections of objects or databases and DataTable instances.

The Dev Codes

.Net

.NET Array Dictionary List String 2D Async DataTable Dates DateTime Enum File For Foreach Format IEnumerable If IndexOf Lambda LINQ Parse Path Process Property Regex Replace Sort Split Static StringBuilder Substring Switch Tuple

Java

Core Array ArrayList HashMap String 2D Cast Character Console Deque Duplicates File For Format HashSet If IndexOf Lambda Math ParseInt Process Random Regex Replace Sort Split StringBuilder Substring Switch Vector While

TheDeveloperBlog.com

VB.NET DataGridView

Related Links:

.Net

Java

Related Links