DomainUpDown.SelectedItem 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

获取或设置基于集合中选定项的索引值的选定项。

public:
 property System::Object ^ SelectedItem { System::Object ^ get(); void set(System::Object ^ value); };

[System.ComponentModel.Browsable(false)]
public object SelectedItem { get; set; }

[System.ComponentModel.Browsable(false)]
public object? SelectedItem { get; set; }

[<System.ComponentModel.Browsable(false)>]
member this.SelectedItem : obj with get, set

Public Property SelectedItem As Object

属性值

Object

基于 SelectedIndex 值的选定项。 默认值是 null。

属性

BrowsableAttribute

示例

下面的代码示例创建并初始化 DomainUpDown 控件。 该示例允许你设置其某些属性，并创建一组字符串以在旋转框中显示， (也称为向上控件) 。 代码假定窗体上已实例化，TextBoxCheckBox并且Button已实例化。 该示例还假定在类级别声明为 32 位有符号整数 myCounter的成员变量。 可以在文本框中输入字符串，并在单击按钮时将其添加到 Items 集合中。 通过单击复选框，可以切换 Sorted 属性并观察旋转框中项集合的差异。

protected:
   DomainUpDown^ domainUpDown1;

private:
   void MySub()
   {
      // Create and initialize the DomainUpDown control.
      domainUpDown1 = gcnew System::Windows::Forms::DomainUpDown;
      
      // Add the DomainUpDown control to the form.
      Controls->Add( domainUpDown1 );
   }

   void button1_Click( System::Object^ sender,
     System::EventArgs^ e )
   {
      // Add the text box contents and initial location in the collection
      // to the DomainUpDown control.
      domainUpDown1->Items->Add( String::Concat(
         (textBox1->Text->Trim()), " - ", myCounter.ToString() ) );
      
      // Increment the counter variable.
      myCounter = myCounter + 1;
      
      // Clear the TextBox.
      textBox1->Text = "";
   }

   void checkBox1_Click( Object^ sender, EventArgs^ e )
   {
      // If Sorted is set to true, set it to false; 
      // otherwise set it to true.
      if ( domainUpDown1->Sorted )
      {
         domainUpDown1->Sorted = false;
      }
      else
      {
         domainUpDown1->Sorted = true;
      }
   }

   void domainUpDown1_SelectedItemChanged( Object^ sender, EventArgs^ e )
   {
      // Display the SelectedIndex and SelectedItem property values in a MessageBox.
      MessageBox::Show( String::Concat( "SelectedIndex: ",
      domainUpDown1->SelectedIndex.ToString(), "\n", "SelectedItem: ",
      domainUpDown1->SelectedItem->ToString() ) );
   }

protected DomainUpDown domainUpDown1;

private void MySub()
 {
    // Create and initialize the DomainUpDown control.
    domainUpDown1 = new System.Windows.Forms.DomainUpDown();
    
    // Add the DomainUpDown control to the form.
    Controls.Add(domainUpDown1);
 }
 
 private void button1_Click(System.Object sender, 
                           System.EventArgs e)
 {   
    // Add the text box contents and initial location in the collection
    // to the DomainUpDown control.
    domainUpDown1.Items.Add((textBox1.Text.Trim()) + " - " + myCounter);
    
    // Increment the counter variable.
    myCounter = myCounter + 1;
 
    // Clear the TextBox.
    textBox1.Text = "";
 }
 
 private void checkBox1_Click(System.Object sender, 
                             System.EventArgs e)
 {
    // If Sorted is set to true, set it to false; 
    // otherwise set it to true.
    if (domainUpDown1.Sorted)
    {
       domainUpDown1.Sorted = false;
    }
    else
    {
       domainUpDown1.Sorted = true;
    }
 }
 
 private void domainUpDown1_SelectedItemChanged(System.Object sender, 
                                               System.EventArgs e)
 {
    // Display the SelectedIndex and SelectedItem property values in a MessageBox.
    MessageBox.Show("SelectedIndex: " + domainUpDown1.SelectedIndex.ToString() 
       + "\n" + "SelectedItem: " + domainUpDown1.SelectedItem.ToString());
 }

Protected domainUpDown1 As DomainUpDown


Private Sub MySub()
    ' Create and initialize the DomainUpDown control.
    domainUpDown1 = New System.Windows.Forms.DomainUpDown()
    
    ' Add the DomainUpDown control to the form.
    Controls.Add(domainUpDown1)
End Sub


Private Sub button1_Click(sender As System.Object, e As System.EventArgs)
    ' Add the text box contents and initial location in the collection
    ' to the DomainUpDown control.
    domainUpDown1.Items.Add((textBox1.Text.Trim() & " - " & myCounter))
    
    ' Increment the counter variable.
    myCounter = myCounter + 1
    
    ' Clear the TextBox.
    textBox1.Text = ""
End Sub


Private Sub checkBox1_Click(sender As System.Object, e As System.EventArgs)
    ' If Sorted is set to true, set it to false; 
    ' otherwise set it to true.
    If domainUpDown1.Sorted Then
        domainUpDown1.Sorted = False
    Else
        domainUpDown1.Sorted = True
    End If
End Sub


Private Sub domainUpDown1_SelectedItemChanged _
    (sender As System.Object, e As System.EventArgs)
    
    ' Display the SelectedIndex and SelectedItem property values in a MessageBox.
    MessageBox.Show(("SelectedIndex: " & domainUpDown1.SelectedIndex.ToString() & _
        ControlChars.Cr & "SelectedItem: " & domainUpDown1.SelectedItem.ToString()))
End Sub

注解

设置此属性后，该值将验证为集合中的项之一，并将 SelectedIndex 该属性设置为适当的索引值。

另请参阅

• SelectedIndex