DataGridViewCellValueEventHandler Delegate

 

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
)

Parameters

sender
Type: System::Object^

The source of the event.

e
Type: System.Windows.Forms::DataGridViewCellValueEventArgs^

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 NIB: 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.

#pragma region Data store maintance

    void VirtualConnector::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 = gcnew Int32(store->default[e->RowIndex]); 
        }
        else if (newRowNeeded && e->RowIndex == numberOfRows)
        {
            if (dataGridView1->IsCurrentCellInEditMode)
            {
                e->Value = initialValue;
            }
            else
            {
                // Show a blank e if the cursor is just loitering
                // over(the) last row.
                e->Value = String::Empty;
            }
        }
        else
        {
            e->Value = e->RowIndex;
        }
    }

    void VirtualConnector::dataGridView1_CellValuePushed
        (Object^ sender, DataGridViewCellValueEventArgs^ e)
    {
        String^ value = e->Value->ToString();
        store[e->RowIndex] = Int32::Parse(value, 
            CultureInfo::CurrentCulture);
    }
#pragma endregion

.NET Framework
Available since 2.0
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