ComboBox.DropDown ComboBox.DropDown ComboBox.DropDown ComboBox.DropDown Event

정의

ComboBox의 드롭다운 부분이 표시될 때 발생합니다.Occurs when the drop-down portion of a ComboBox is shown.

public:
 event EventHandler ^ DropDown;
public event EventHandler DropDown;
member this.DropDown : EventHandler 
Public Custom Event DropDown As EventHandler 

예제

다음 코드 예제에는 초기화 하는 방법을 보여 줍니다.는 ComboBox text 속성을 설정 하 고 컨트롤을 AddRange 9e4af80fa7c0">getroot() 메서드를를 ComboBox.The following code example demonstrates how to initialize a ComboBox control by setting the text property and using the AddRange method to populate the ComboBox. 처리 하는 방법도 보여 줍니다는 DropDown 이벤트입니다.It also demonstrates handling the DropDown event. 예제를 실행 하려면 호출을 폼에 다음 코드를 붙여 합니다 InitializeComboBox 폼의 생성자 또는 Load 이벤트입니다.To run the example, paste the following code in a form and call the InitializeComboBox method in the form's constructor or Load event.

internal:
   // Declare ComboBox1
   System::Windows::Forms::ComboBox^ ComboBox1;

private:
   // Initialize ComboBox1.
   void InitializeComboBox()
   {
      this->ComboBox1 = gcnew ComboBox;
      this->ComboBox1->Location = System::Drawing::Point( 128, 48 );
      this->ComboBox1->Name = "ComboBox1";
      this->ComboBox1->Size = System::Drawing::Size( 100, 21 );
      this->ComboBox1->TabIndex = 0;
      this->ComboBox1->Text = "Typical";
      array<String^>^ installs = {"Typical","Compact","Custom"};
      ComboBox1->Items->AddRange( installs );
      this->Controls->Add( this->ComboBox1 );
      
      // Hook up the event handler.
      this->ComboBox1->DropDown += gcnew System::EventHandler(
         this, &Form1::ComboBox1_DropDown );
   }

   // Handles the ComboBox1 DropDown event. If the user expands the  
   // drop-down box, a message box will appear, recommending the
   // typical installation.
   void ComboBox1_DropDown( Object^ sender, System::EventArgs^ e )
   {
      MessageBox::Show( "Typical installation is strongly recommended.",
         "Install information", MessageBoxButtons::OK,
         MessageBoxIcon::Information );
   }
   
// Declare ComboBox1.
internal System.Windows.Forms.ComboBox ComboBox1;
   
// Initialize ComboBox1.
private void InitializeComboBox()
{
	this.ComboBox1 = new ComboBox();
	this.ComboBox1.Location = new System.Drawing.Point(128, 48);
	this.ComboBox1.Name = "ComboBox1";
	this.ComboBox1.Size = new System.Drawing.Size(100, 21);
	this.ComboBox1.TabIndex = 0;
	this.ComboBox1.Text	= "Typical";
	string[] installs = new string[]{"Typical", "Compact", "Custom"};
	ComboBox1.Items.AddRange(installs);
	this.Controls.Add(this.ComboBox1);
	
	// Hook up the event handler.
	this.ComboBox1.DropDown +=  
		new System.EventHandler(ComboBox1_DropDown);
}

// Handles the ComboBox1 DropDown event. If the user expands the  
// drop-down box, a message box will appear, recommending the
// typical installation.
private void ComboBox1_DropDown(object sender, System.EventArgs e)
{
	MessageBox.Show("Typical installation is strongly recommended.", 
	"Install information", MessageBoxButtons.OK, 
		MessageBoxIcon.Information);
}

' Declare ComboBox1.
Friend WithEvents ComboBox1 As System.Windows.Forms.ComboBox

' Initialize ComboBox1.
Private Sub InitializeComboBox()
    Me.ComboBox1 = New ComboBox
    Me.ComboBox1.Location = New System.Drawing.Point(128, 48)
    Me.ComboBox1.Name = "ComboBox1"
    Me.ComboBox1.Size = New System.Drawing.Size(100, 21)
    Me.ComboBox1.TabIndex = 0
    Me.ComboBox1.Text = "Typical"
    Dim installs() As String = New String() _
        {"Typical", "Compact", "Custom"}
    ComboBox1.Items.AddRange(installs)
    Me.Controls.Add(Me.ComboBox1)
End Sub

' Handles the ComboBox1 DropDown event. If the user expands the  
' drop-down box, a message box will appear, recommending the
' typical installation.
Private Sub ComboBox1_DropDown _ 
    (ByVal sender As Object, ByVal e As System.EventArgs) _ 
    Handles ComboBox1.DropDown
    MessageBox.Show("Typical installation is strongly recommended.", _
    "Install information", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub

설명

이벤트 처리에 대한 자세한 내용은 이벤트 처리 및 발생 을 참조하십시오.For more information about handling events, see Handling and Raising Events.

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