Gets the currently active multiple-document interface (MDI) child window.
<BrowsableAttribute(False)> _ Public ReadOnly Property ActiveMdiChild As Form
[BrowsableAttribute(false)] public Form ActiveMdiChild { get; }
[BrowsableAttribute(false)] public: property Form^ ActiveMdiChild { Form^ get (); }
[<BrowsableAttribute(false)>] member ActiveMdiChild : Form
You can use this method to determine whether there are any MDI child forms open in your MDI application. You can also use this method to perform operations on an MDI child window from its MDI parent form or from another form that is displayed in your application.
If the currently active form is not an MDI child form, you can use the ActiveForm property to obtain a reference to it.
The following code example obtains a reference to the active MDI child form and loops through all TextBox controls on the form, resetting their Text properties. This example requires that an MDI parent form has been created and that this method call is being made from the MDI parent form.
Public Sub ClearAllChildFormText() ' Obtain a reference to the currently active MDI child form. Dim tempChild As Form = Me.ActiveMdiChild ' Loop through all controls on the child form. Dim i As Integer For i = 0 To tempChild.Controls.Count - 1 ' Determine if the current control on the child form is a TextBox. If TypeOf tempChild.Controls(i) Is TextBox Then ' Clear the contents of the control since it is a TextBox. tempChild.Controls(i).Text = "" End If Next i End Sub 'ClearAllChildFormText
public void ClearAllChildFormText() { // Obtain a reference to the currently active MDI child form. Form tempChild = this.ActiveMdiChild; // Loop through all controls on the child form. for (int i = 0; i < tempChild.Controls.Count; i++) { // Determine if the current control on the child form is a TextBox. if (tempChild.Controls[i] is TextBox) { // Clear the contents of the control since it is a TextBox. tempChild.Controls[i].Text = ""; } } }
public: void ClearAllChildFormText() { // Obtain a reference to the currently active MDI child form. Form^ tempChild = this->ActiveMdiChild; // Loop through all controls on the child form. for ( int i = 0; i < tempChild->Controls->Count; i++ ) { // Determine if the current control on the child form is a TextBox. if ( dynamic_cast<TextBox^>(tempChild->Controls[ i ]) ) { // Clear the contents of the control since it is a TextBox. tempChild->Controls[ i ]->Text = ""; } } }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2