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DataGridViewCellValueEventHandler Delegate

Note: This delegate is new in the .NET Framework version 2.0.

Represents the method that will handle the CellValueNeeded event or CellValuePushed event of a DataGridView.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

public delegate void DataGridViewCellValueEventHandler (
	Object sender,
	DataGridViewCellValueEventArgs e
)
/** @delegate */
public delegate void DataGridViewCellValueEventHandler (
	Object sender, 
	DataGridViewCellValueEventArgs e
)
JScript supports the use of delegates, but not the declaration of new ones.

Parameters

sender

The source of the event.

e

A DataGridViewCellValueEventArgs that contains the event data.

Use this delegate to implement virtual mode in the DataGridView control. For more information about virtual mode, see Virtual Mode in the Windows Forms DataGridView Control.

When you create a DataGridViewCellValueEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Events and Delegates.

The following code example handles the CellValuePushed event to store updates and new entries in a data store object. This example is part of a larger example available in the DataGridView.VirtualMode reference topic.

#region "data store maintance"
const int initialValue = -1;

private void dataGridView1_CellValueNeeded(object sender,
    DataGridViewCellValueEventArgs e)
{
    if (store.ContainsKey(e.RowIndex))
    {
        // Use the store if the e value has been modified 
        // and stored.            
        e.Value = store[e.RowIndex];
    }
    else if (newRowNeeded && e.RowIndex == numberOfRows)
    {
        if (dataGridView1.IsCurrentCellInEditMode)
        {
            e.Value = initialValue;
        }
        else
        {
            // Show a blank value if the cursor is just resting
            // on the last row.
            e.Value = String.Empty;
        }
    }
    else
    {
        e.Value = e.RowIndex;
    }
}

private void dataGridView1_CellValuePushed(object sender,
    DataGridViewCellValueEventArgs e)
{
    store.Add(e.RowIndex, int.Parse(e.Value.ToString()));
}
#endregion

private Dictionary<int, int> store = new Dictionary<int, int>();

#region "data store maintance"
private final int INITIALVALUE = -1;

private void dataGridView1_CellValueNeeded(Object sender,
    DataGridViewCellValueEventArgs e)
{
    if (store.ContainsKey(e.get_RowIndex())) {
        // Use the store if the e value has been modified 
        // and stored.            
        e.set_Value((Int32)store.get_Item(e.get_RowIndex()));
    }
    else {
        if (newRowNeeded && e.get_RowIndex() == numberOfRows) {
            if (dataGridView1.get_IsCurrentCellInEditMode()) {
                e.set_Value((Int32)INITIALVALUE);
            }
            else {
                // Show a blank e if the cursor is just loitering
                // over(the)
                // last row.
                e.set_Value("");
            }
        }
        else {
            e.set_Value((Int32)e.get_RowIndex());
        }
    }
} //dataGridView1_CellValueNeeded

private void dataGridView1_CellValuePushed(Object sender,
    DataGridViewCellValueEventArgs e)
{
    store.Add(e.get_RowIndex(), Int32.Parse(e.get_Value().ToString()));
} //dataGridView1_CellValuePushed
#endregion

private Dictionary<int, int> store = new Dictionary<int, int>();

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0
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