DataGridView in Windows Forms – Tips, Tricks and Frequently Asked Questions(FAQ)

DataGridView control is a Windows Forms control that gives you the ability to customize and edit tabular data. It gives you number of properties, methods and events to customize its appearance and behavior. In this article, we will discuss some frequently asked questions and their solutions. These questions have been collected from a variety of sources including some newsgroups, MSDN site and a few, answered by me at the MSDN forums.

Tip 1 – Populating a DataGridView

In this short snippet, we will populate a DataGridView using the LoadData() method. This method uses the SqlDataAdapter to populate a DataSet. The table ‘Orders’ in the DataSet is then bound to the BindingSource component which gives us the flexibility to choose/modify the data location.

C#

publicpartialclassForm1:Form

{

privateSqlDataAdapterda;

privateSqlConnectionconn;

BindingSourcebsource =newBindingSource();

DataSetds =null;

stringsql;

publicForm1()

{

InitializeComponent();

}

privatevoidbtnLoad_Click(objectsender,EventArgse)

{

LoadData();

}

privatevoidLoadData()

{

stringconnectionString ="Data Source=localhost;Initial Catalog=Northwind;"+"Integrated Security=SSPI;";

conn =newSqlConnection(connectionString);

sql ="SELECT OrderID, CustomerID, EmployeeID, OrderDate, Freight,"+"ShipName, ShipCountry FROM Orders";

da =newSqlDataAdapter(sql, conn);

conn.Open();

ds =newDataSet();

SqlCommandBuildercommandBuilder =newSqlCommandBuilder(da);

da.Fill(ds,"Orders");

bsource.DataSource = ds.Tables["Orders"];

dgv.DataSource = bsource;

}

}

VB.NET

PublicPartialClassForm1

InheritsForm

PrivatedaAsSqlDataAdapter

PrivateconnAsSqlConnection

PrivatebsourceAsBindingSource =NewBindingSource()

PrivatedsAsDataSet =Nothing

PrivatesqlAsString

PublicSubNew()

InitializeComponent()

EndSub

PrivateSubbtnLoad_Click(ByValsenderAsObject,ByValeAsEventArgs)

LoadData()

EndSub

PrivateSubLoadData()

DimconnectionStringAsString= "Data Source=localhost;Initial Catalog=Northwind;" & "Integrated Security=SSPI;"

conn =NewSqlConnection(connectionString)

sql = "SELECT OrderID, CustomerID, EmployeeID, OrderDate, Freight," & "ShipName, ShipCountry FROM Orders"

da =NewSqlDataAdapter(sql, conn)

conn.Open()

ds =NewDataSet()

DimcommandBuilderAsSqlCommandBuilder =NewSqlCommandBuilder(da)

da.Fill(ds, "Orders")

bsource.DataSource = ds.Tables("Orders")

dgv.DataSource = bsource

EndSub

EndClass

Tip 2 – Update the data in the DataGridView and save changes in the database

After editing the data in the cells, if you would like to update the changes permanently in the database, use the following code:

C#

privatevoidbtnUpdate_Click(objectsender,EventArgse)

{

DataTabledt = ds.Tables["Orders"];

this.dgv.BindingContext[dt].EndCurrentEdit();

this.da.Update(dt);

}

VB.NET

PrivateSubbtnUpdate_Click(ByValsenderAsObject,ByValeAsEventArgs)

DimdtAsDataTable = ds.Tables("Orders")

Me.dgv.BindingContext(dt).EndCurrentEdit()

Me.da.Update(dt)

EndSub

Tip 3 – Display a confirmation box before deleting a row in the DataGridView

Handle the UserDeletingRow event to display a confirmation box to the user. If the user confirms the deletion, delete the row. If the user clicks cancel, set e.cancel = true which cancels the row deletion.

C#

privatevoiddgv_UserDeletingRow(objectsender,DataGridViewRowCancelEventArgse)

{

if(!e.Row.IsNewRow)

{

DialogResultres =MessageBox.Show("Are you sure you want to delete this row?","Delete confirmation",

MessageBoxButtons.YesNo,MessageBoxIcon.Question);

if(res ==DialogResult.No)

e.Cancel =true;

}

}

VB.NET

PrivateSubdgv_UserDeletingRow(ByValsenderAsObject,ByValeAsDataGridViewRowCancelEventArgs)

If(Note.Row.IsNewRow)Then

DimresAsDialogResult = MessageBox.Show("Are you sure you want to delete this row?", "Delete confirmation", MessageBoxButtons.YesNo, MessageBoxIcon.Question)

Ifres = DialogResult.NoThen

e.Cancel =True

EndIf

EndIf

EndSub

Tip 4 – How to autoresize column width in the DataGridView

The snippet shown below, first auto-resizes the columns to fit its content. Then the AutoSizeColumnsMode is set to the ‘DataGridViewAutoSizeColumnsMode.AllCells’ enumeration value which automatically adjust the widths of the columns when the data changes.

C#

privatevoidbtnResize_Click(objectsender,EventArgse)

{

dgv.AutoResizeColumns();

dgv.AutoSizeColumnsMode =DataGridViewAutoSizeColumnsMode.AllCells;

}

VB.NET

PrivateSubbtnResize_Click(ByValsenderAsObject,ByValeAsEventArgs)

dgv.AutoResizeColumns()

dgv.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells

EndSub

Tip 5 - Select and Highlight an entire row in DataGridView

C#

introwToBeSelected = 3;// third row

if(dgv.Rows.Count >= rowToBeSelected)

{

// Since index is zero based, you have to subtract 1

dgv.Rows[rowToBeSelected - 1].Selected =true;

}

VB.NET

DimrowToBeSelectedAsInteger= 3' third row

Ifdgv.Rows.Count >= rowToBeSelectedThen

' Since index is zero based, you have to subtract 1

dgv.Rows(rowToBeSelected - 1).Selected =True

EndIf

Tip 6 - How to scroll programmatically to a row in the DataGridView

The DataGridView has a property called FirstDisplayedScrollingRowIndex that can be used in order to scroll to a row programmatically.

C#

intjumpToRow = 20;

if(dgv.Rows.Count >= jumpToRow && jumpToRow >= 1)

{

dgv.FirstDisplayedScrollingRowIndex = jumpToRow;

dgv.Rows[jumpToRow].Selected =true;

}

VB.NET

DimjumpToRowAsInteger= 20

Ifdgv.Rows.Count >= jumpToRowAndAlsojumpToRow >= 1Then

dgv.FirstDisplayedScrollingRowIndex = jumpToRow

dgv.Rows(jumpToRow).Selected =True

EndIf

Tip 7 - Calculate a column total in the DataGridView and display in a textbox

A common requirement is to calculate the total of a currency field and display it in a textbox. In the snippet below, we will be calculating the total of the ‘Freight’ field. We will then display the data in a textbox by formatting the result (observe theToString("c")) while displaying the data, which displays the culture-specific currency.

C#

privatevoidbtnTotal_Click(objectsender,EventArgse)

{

if(dgv.Rows.Count > 0)

txtTotal.Text = Total().ToString("c");

}

privatedoubleTotal()

{

doubletot = 0;

inti = 0;

for(i = 0; i < dgv.Rows.Count; i++)

{

tot = tot +Convert.ToDouble(dgv.Rows[i].Cells["Freight"].Value);

}

returntot;

}

VB.NET

PrivateSubbtnTotal_Click(ByValsenderAsObject,ByValeAsEventArgs)

Ifdgv.Rows.Count > 0Then

txtTotal.Text = Total().ToString("c")

EndIf

EndSub

PrivateFunctionTotal()AsDouble

DimtotAsDouble= 0

DimiAsInteger= 0

Fori = 0Todgv.Rows.Count - 1

tot = tot + Convert.ToDouble(dgv.Rows(i).Cells("Freight").Value)

Nexti

Returntot

EndFunction

Tip 8 - Change the Header Names in the DataGridView

If the columns being retrieved from the database do not have meaningful names, we always have the option of changing the header names as shown in this snippet:

C#

privatevoidbtnChange_Click(objectsender,EventArgse)

{

dgv.Columns[0].HeaderText ="MyHeader1";

dgv.Columns[1].HeaderText ="MyHeader2";

}

VB.NET

PrivateSubbtnChange_Click(ByValsenderAsObject,ByValeAsEventArgs)

dgv.Columns(0).HeaderText = "MyHeader1"

dgv.Columns(1).HeaderText = "MyHeader2"

EndSub

Tip 9 - Change the Color of Cells, Rows and Border in the DataGridView

C#

privatevoidbtnCellRow_Click(objectsender,EventArgse)

{

// Change ForeColor of each Cell

this.dgv.DefaultCellStyle.ForeColor =Color.Coral;

// Change back color of each row

this.dgv.RowsDefaultCellStyle.BackColor =Color.AliceBlue;

// Change GridLine Color

this.dgv.GridColor =Color.Blue;

// Change Grid Border Style

this.dgv.BorderStyle =BorderStyle.Fixed3D;

}

VB.NET

PrivateSubbtnCellRow_Click(ByValsenderAsObject,ByValeAsEventArgs)

' Change ForeColor of each Cell

Me.dgv.DefaultCellStyle.ForeColor = Color.Coral

' Change back color of each row

Me.dgv.RowsDefaultCellStyle.BackColor = Color.AliceBlue

' Change GridLine Color

Me.dgv.GridColor = Color.Blue

' Change Grid Border Style

Me.dgv.BorderStyle = BorderStyle.Fixed3D

EndSub

Tip 10 - Hide a Column in the DataGridView

If you would like to hide a column based on a certain condition, here’s a snippet for that.

C#

privatevoidbtnHide_Click(objectsender,EventArgse)

{

this.dgv.Columns["EmployeeID"].Visible =false;

}

VB.NET

PrivateSubbtnHide_Click(ByValsenderAsObject,ByValeAsEventArgs)

Me.dgv.Columns("EmployeeID").Visible =False

EndSub

Tip 11 - Handle SelectedIndexChanged of a ComboBox in the DataGridView

To handle the SelectedIndexChanged event of a DataGridViewComboBox, you need to use the DataGridView.EditingControlShowing event as shown below. You can then retrieve the selected index or the selected text of the combobox.

C#

privatevoiddataGridView1_EditingControlShowing(objectsender,DataGridViewEditingControlShowingEventArgse)

{

ComboBoxeditingComboBox = (ComboBox)e.Control;

if(editingComboBox !=null)

editingComboBox.SelectedIndexChanged +=newSystem.EventHandler(this.editingComboBox_SelectedIndexChanged);

}

privatevoideditingComboBox_SelectedIndexChanged(objectsender, System.EventArgse)

{

ComboBoxcomboBox1 = (ComboBox)sender;

// Display index

MessageBox.Show(comboBox1.SelectedIndex.ToString());

// Display value

MessageBox.Show(comboBox1.Text);

}

VB.NET

PrivateSubdataGridView1_EditingControlShowing(ByValsenderAsObject,ByValeAsDataGridViewEditingControlShowingEventArgs)

DimeditingComboBoxAsComboBox =CType(e.Control, ComboBox)

IfNoteditingComboBoxIsNothingThen

AddHandlereditingComboBox.SelectedIndexChanged,AddressOfeditingComboBox_SelectedIndexChanged

EndIf

EndSub

PrivateSubeditingComboBox_SelectedIndexChanged(ByValsenderAsObject,ByValeAsSystem.EventArgs)

DimcomboBox1AsComboBox =CType(sender, ComboBox)

' Display index

MessageBox.Show(comboBox1.SelectedIndex.ToString())

' Display value

MessageBox.Show(comboBox1.Text)

EndSub

Tip 12 - Change Color of Alternate Rows in the DataGridView

C#

privatevoidbtnAlternate_Click(objectsender,EventArgse)

{

this.dgv.RowsDefaultCellStyle.BackColor =Color.White;

this.dgv.AlternatingRowsDefaultCellStyle.BackColor =Color.Aquamarine;

}

VB.NET

PrivateSubbtnAlternate_Click(ByValsenderAsObject,ByValeAsEventArgs)

Me.dgv.RowsDefaultCellStyle.BackColor = Color.White

Me.dgv.AlternatingRowsDefaultCellStyle.BackColor = Color.Aquamarine

EndSub

Tip 13 - Formatting Data in the DataGridView

The DataGridView exposes properties that enable you to format data such as displaying a currency column in the culture specific currency or displaying nulls in a desired format and so on.

C#

privatevoidbtnFormat_Click(objectsender,EventArgse)

{

// display currency in culture-specific currency for

this.dgv.Columns["Freight"].DefaultCellStyle.Format ="c";

// display nulls as 'NA'

this.dgv.DefaultCellStyle.NullValue ="NA";

}

VB.NET

PrivateSubbtnFormat_Click(ByValsenderAsObject,ByValeAsEventArgs)

' display currency in culture-specific currency for

Me.dgv.Columns("Freight").DefaultCellStyle.Format = "c"

' display nulls as 'NA'

Me.dgv.DefaultCellStyle.NullValue = "NA"

EndSub

Tip 14 – Change the order of columns in the DataGridView

In order to change the order of columns, just set the DisplayIndex property of the DataGridView to the desired value. Remember that the index is zero based.

C#

privatevoidbtnReorder_Click(objectsender,EventArgse)

{

dgv.Columns["CustomerID"].DisplayIndex = 5;

dgv.Columns["OrderID"].DisplayIndex = 3;

dgv.Columns["EmployeeID"].DisplayIndex = 1;

dgv.Columns["OrderDate"].DisplayIndex = 2;

dgv.Columns["Freight"].DisplayIndex = 6;

dgv.Columns["ShipCountry"].DisplayIndex = 0;

dgv.Columns["ShipName"].DisplayIndex = 4;

}

VB.NET

PrivateSubbtnReorder_Click(ByValsenderAsObject,ByValeAsEventArgs)

dgv.Columns("CustomerID").DisplayIndex = 5

dgv.Columns("OrderID").DisplayIndex = 3

dgv.Columns("EmployeeID").DisplayIndex = 1

dgv.Columns("OrderDate").DisplayIndex = 2

dgv.Columns("Freight").DisplayIndex = 6

dgv.Columns("ShipCountry").DisplayIndex = 0

dgv.Columns("ShipName").DisplayIndex = 4

EndSub

I hope this article was useful and I thank you for viewing it.

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