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Control.OnDoubleClick Method

Raises the DoubleClick event.

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

protected virtual void OnDoubleClick (
	EventArgs e
)
protected void OnDoubleClick (
	EventArgs e
)
protected function OnDoubleClick (
	e : EventArgs
)
Not applicable.

Parameters

e

An EventArgs that contains the event data.

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The OnDoubleClick method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors: When overriding OnDoubleClick in a derived class, be sure to call the base class's OnDoubleClick method so that registered delegates receive the event.

The following code example uses the DoubleClick event of a ListBox to load text files listed in the ListBox into a TextBox control.

// This example uses the DoubleClick event of a ListBox to load text files
// listed in the ListBox into a TextBox control. This example
// assumes that the ListBox, named listBox1, contains a list of valid file
// names with path and that this event handler method
// is connected to the DoublClick event of a ListBox control named listBox1.
// This example requires code access permission to access files.
private void listBox1_DoubleClick(object sender, System.EventArgs e)
{
    // Get the name of the file to open from the ListBox.
    String file = listBox1.SelectedItem.ToString();

    try
    {
        // Determine if the file exists before loading.
        if (System.IO.File.Exists(file))
        {
            // Open the file and use a TextReader to read the contents into the TextBox.
            System.IO.FileInfo myFile = new System.IO.FileInfo(listBox1.SelectedItem.ToString());
            System.IO.TextReader myData = myFile.OpenText();;

            textBox1.Text = myData.ReadToEnd();
            myData.Close();
        }
    }
        // Exception is thrown by the OpenText method of the FileInfo class.
    catch(System.IO.FileNotFoundException)
    {
        MessageBox.Show("The file you specified does not exist.");
    }
        // Exception is thrown by the ReadToEnd method of the TextReader class.
    catch(System.IO.IOException)
    {
        MessageBox.Show("There was a problem loading the file into the TextBox. Ensure that the file is a valid text file.");
    }
}

// This example uses the DoubleClick event of a ListBox to load text files
// listed in the ListBox into a TextBox control. This example
// assumes that the ListBox, named listBox1, contains a list of valid file
// names with path and that this event handler method
// is connected to the DoublClick event of a ListBox control named listBox1.
// This example requires code access permission to access files.
private void listBox1_DoubleClick(Object sender, System.EventArgs e)
{
    // Get the name of the file to open from the ListBox.
    String file = listBox1.get_SelectedItem().ToString();
    try {
        // Determine if the file exists before loading.
        if (System.IO.File.Exists(file)) {
            // Open the file and use a TextReader to read the contents 
            // into the TextBox.
            System.IO.FileInfo myFile = new System.IO.FileInfo(listBox1.
                get_SelectedItem().ToString());
            System.IO.TextReader myData = myFile.OpenText();
            textBox1.set_Text(myData.ReadToEnd());
            myData.Close();
        }
    }
    // Exception is thrown by the OpenText method of the FileInfo class.
    catch (System.IO.FileNotFoundException exp) {
        MessageBox.Show("The file you specified does not exist.");
    }
    // Exception is thrown by the ReadToEnd method of the TextReader class.
    catch (System.IO.IOException exp) {
        MessageBox.Show("There was a problem loading the file into the "
            + "TextBox. Ensure that the file is a valid text file.");
    }
} //listBox1_DoubleClick

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0
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