Drag and Drop Functionality

Drag and Drop Functionality

Download DragDropSample.zip - 36.1 KB http://www.codeproject.com/useritems/Drag_Drop_from_GridView/DragDropSample.zip

Original Article by Mr. Nauman Bhatti

Introduction

In the article, we will learn how to drag a cell's text from a DataGridView and drop it to Textbox or RichTextBox control




Using the code

In the drag operation of a text from the DataGridView cell, the following
events participate:

dataGridView1_MouseDown

This event occurs when the mouse pointer is over the control and a mouse button
is pressed. We use this event to capture the cell's text which is being dragged
from the DataGridView. The following line of code accomplishes this:

if (e.Button == MouseButtons.Left)
{
DataGridView.HitTestInfo info = dataGridView1.HitTest(e.X, e.Y);
if (info.RowIndex >= 0)
{
if (info.RowIndex >= 0 && info.ColumnIndex >= 0)
{
string text = (String)dataGridView1.Rows[info.RowIndex].Cells info.ColumnIndex].Value;
if (text != null)
dataGridView1.DoDragDrop(text, DragDropEffects.Copy);
}
}
}

DataGridView.HitTestInfo, Contains information, such as the row and column indexes, about a specific coordinate pair in the DataGridView control. This class cannot be inherited.

This is all that you have to write on DataGridView's events.

Drop a text on TextBox

textBox1_DragDrop

This event occurs when the mouse pointer is on the textbox control and mouse button is released. you have to typecast the data from the DragEventArgs to assign it to the text property of the textbox.

private void textBox1_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(System.String)))
{
textBox1.Text = (System.String)e.Data.GetData(typeof(System.String));
}
}

textBox1_DragEnter

This event occurs when the mouse pointer is dragged and it enters in the
textbox. Here you have to specify the effects of the drap-drop opertaion

private void textBox1_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy;
}

Other then this you also have to set the "AllowDrop" property of the textbox to
"true".

Drop a text in RichTextBox

To drop a text in the RichTextBox you only have to set it's "EnableAutoDragDrop"
property to "true".