ComboBoxRenderer.IsSupported ComboBoxRenderer.IsSupported ComboBoxRenderer.IsSupported ComboBoxRenderer.IsSupported Property

定义

获取一个值,该值指示是否可使用 ComboBoxRenderer 类以视觉样式绘制组合框。Gets a value indicating whether the ComboBoxRenderer class can be used to draw a combo box with visual styles.

public:
 static property bool IsSupported { bool get(); };
public static bool IsSupported { get; }
member this.IsSupported : bool
Public Shared ReadOnly Property IsSupported As Boolean

属性值

如果用户已在操作系统中启用了视觉样式,并将视觉样式应用于应用程序窗口的工作区,则为 true;否则为 falsetrue if the user has enabled visual styles in the operating system and visual styles are applied to the client area of application windows; otherwise, false.

示例

下面的代码示例使用IsSupported属性来确定是否要ComboBoxRenderer使用方法。The following code example uses the IsSupported property to determine whether to use the ComboBoxRenderer methods. 此代码示例是为ComboBoxRenderer类提供的更大示例的一部分。This code example is part of a larger example provided for the ComboBoxRenderer class.

      // Draw the combo box in the current state.
protected:
    virtual void OnPaint(PaintEventArgs^ e) override 
    {
        Control::OnPaint(e);

        if (!ComboBoxRenderer::IsSupported)
        {
            this->Parent->Text = "Visual Styles Disabled";
            return;
        }

        this->Parent->Text = "CustomComboBox Enabled";

        // Always draw the main text box and drop down arrow in their
        // current states
        ComboBoxRenderer::DrawTextBox(e->Graphics, topTextBoxRectangle,
            this->Text, this->Font, textBoxState);
        ComboBoxRenderer::DrawDropDownButton(e->Graphics, arrowRectangle,
            arrowState);

        // Only draw the bottom text box if the arrow has been clicked
        if (isActivated)
        {
            ComboBoxRenderer::DrawTextBox(e->Graphics,
                bottomTextBoxRectangle, bottomText, this->Font,
                textBoxState);
        }
    }
// Draw the combo box in the current state.
protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    if (!ComboBoxRenderer.IsSupported)
    {
        this.Parent.Text = "Visual Styles Disabled";
        return;
    }

    this.Parent.Text = "CustomComboBox Enabled";

    // Always draw the main text box and drop down arrow in their 
    // current states
    ComboBoxRenderer.DrawTextBox(e.Graphics, topTextBoxRectangle,
        this.Text, this.Font, textBoxState);
    ComboBoxRenderer.DrawDropDownButton(e.Graphics, arrowRectangle,
        arrowState);

    // Only draw the bottom text box if the arrow has been clicked
    if (isActivated)
    {
        ComboBoxRenderer.DrawTextBox(e.Graphics,
            bottomTextBoxRectangle, bottomText, this.Font,
            textBoxState);
    }
}
' Draw the combo box in the current state.
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
    MyBase.OnPaint(e)

    If Not ComboBoxRenderer.IsSupported Then
        Me.Parent.Text = "Visual Styles	Disabled"
        Return
    End If

    Me.Parent.Text = "CustomComboBox Enabled"

    ' Always draw the main text box and drop down arrow in their 
    ' current states.
    ComboBoxRenderer.DrawTextBox(e.Graphics, topTextBoxRectangle, _
        Me.Text, Me.Font, textBoxState)
    ComboBoxRenderer.DrawDropDownButton(e.Graphics, arrowRectangle, _
        arrowState)

    ' Only draw the bottom text box if the arrow has been clicked.
    If isActivated Then
        ComboBoxRenderer.DrawTextBox(e.Graphics, _
            bottomTextBoxRectangle, bottomText, Me.Font, textBoxState)
    End If
End Sub

注解

如果此属性为false DrawTextBox , DrawDropDownButtonInvalidOperationException或方法将引发。If this property is false, the DrawTextBox or DrawDropDownButton methods will throw an InvalidOperationException.

适用于

另请参阅