Control.OnControlRemoved Method (ControlEventArgs)
.NET Framework (current version)
Raises the ControlRemoved event.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
Parameters
- e
-
Type:
System.Windows.Forms.ControlEventArgs
A ControlEventArgs that contains the event data.
Called when a child control is removed from the control.
Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.
The OnControlRemoved 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 OnControlRemoved in a derived class, be sure to call the base class's OnControlRemoved method so that registered delegates receive the event.
The following code example uses ControlRemoved to remove a control from a form and displays the name of the removed control in a MessageBox.
// This example demonstrates the use of the ControlAdded and // ControlRemoved events. This example assumes that two Button controls // are added to the form and connected to the addControl_Click and // removeControl_Click event-handler methods. private void Form1_Load(object sender, System.EventArgs e) { // Connect the ControlRemoved and ControlAdded event handlers // to the event-handler methods. // ControlRemoved and ControlAdded are not available at design time. this.ControlRemoved += new System.Windows.Forms.ControlEventHandler(this.Control_Removed); this.ControlAdded += new System.Windows.Forms.ControlEventHandler(this.Control_Added); } private void Control_Added(object sender, System.Windows.Forms.ControlEventArgs e) { MessageBox.Show("The control named " + e.Control.Name + " has been added to the form."); } private void Control_Removed(object sender, System.Windows.Forms.ControlEventArgs e) { MessageBox.Show("The control named " + e.Control.Name + " has been removed from the form."); } // Click event handler for a Button control. Adds a TextBox to the form. private void addControl_Click(object sender, System.EventArgs e) { // Create a new TextBox control and add it to the form. TextBox textBox1 = new TextBox(); textBox1.Size = new Size(100,10); textBox1.Location = new Point(10,10); // Name the control in order to remove it later. The name must be specified // if a control is added at run time. textBox1.Name = "textBox1"; // Add the control to the form's control collection. this.Controls.Add(textBox1); } // Click event handler for a Button control. // Removes the previously added TextBox from the form. private void removeControl_Click(object sender, System.EventArgs e) { // Loop through all controls in the form's control collection. foreach (Control tempCtrl in this.Controls) { // Determine whether the control is textBox1, // and if it is, remove it. if (tempCtrl.Name == "textBox1") { this.Controls.Remove(tempCtrl); } } }
.NET Framework
Available since 1.1
Available since 1.1
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