ComboBoxRenderer.IsSupported 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

取得值，指出 ComboBoxRenderer 類別是否可用來繪製具有視覺化樣式的下拉式方塊。

public:
 static property bool IsSupported { bool get(); };

public static bool IsSupported { get; }

static member IsSupported : bool

Public Shared ReadOnly Property IsSupported As Boolean

屬性值

Boolean

如果使用者在作業系統中已經啟用視覺化樣式，而且應用程式視窗的工作區中已經套用視覺化樣式，則為 true，否則為 false。

範例

下列程式碼範例會 IsSupported 使用 屬性來判斷是否要使用 ComboBoxRenderer 方法。 此程式碼範例是提供給 類別之較大範例的 ComboBoxRenderer 一部分。

      // 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

備註

如果這個屬性是 false ， DrawTextBox 或 DrawDropDownButton 方法會擲回 InvalidOperationException 。

另請參閱

• VisualStyleState