如何绘制具有非标准背景色的按钮?

ButtonRenderer使用VisualStyleRenderer.DruckGround()绘制按钮背景。该方法非常了解用户选择的主题,按钮的背景将使用主题指定的颜色。使用非标准背景色将违反用户选择的主题。你不能两全其美。

Button类实际上不使用ButtonRender,它使用从System.Windows.Forms.ButtonInternal命名空间中的内部ButtonBaseAdapter类派生的三个呈现器之一。这些渲染器是内部的,您不能在自己的代码中使用它们。用反射器或参考源查看它们,看看需要什么。重点介绍PaintButtonBackground方法。

使用提供的ControlPaint和TextRenderer类绘制您自己的按钮。这相当简单。我很快将这些代码组合起来,向您展示。您可以通过设置边框样式等来美化按钮的外观。

    private ButtonState state = ButtonState.Normal;
    public ButtonCell(): base()
    {
        this.Size = new Size(100, 40);
        this.Location = new Point(50, 50);
        this.Font = SystemFonts.IconTitleFont;
        this.Text = "Click here";     
    }
    private void DrawFocus()
    {
        Graphics g = Graphics.FromHwnd(this.Handle);
        Rectangle r = Rectangle.Inflate(this.ClientRectangle, -4, -4);
        ControlPaint.DrawFocusRectangle(g, r);
        g.Dispose();
    }
    private void DrawFocus(Graphics g)
    {
        Rectangle r = Rectangle.Inflate(this.ClientRectangle, -4, -4);
        ControlPaint.DrawFocusRectangle(g, r);
    }
    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        if (state == ButtonState.Pushed)
            ControlPaint.DrawBorder3D(e.Graphics, e.ClipRectangle, Border3DStyle.Sunken);
        else
            ControlPaint.DrawBorder3D(e.Graphics, e.ClipRectangle, Border3DStyle.Raised);
        TextRenderer.DrawText(e.Graphics, Text, this.Font, e.ClipRectangle, this.ForeColor,
            TextFormatFlags.HorizontalCenter | TextFormatFlags.VerticalCenter);
    }
    protected override void OnGotFocus(EventArgs e)
    {
        DrawFocus();
        base.OnGotFocus(e);
    }
    protected override void OnLostFocus(EventArgs e)
    {
        Invalidate();
        base.OnLostFocus(e);
    }
    protected override void OnMouseEnter(EventArgs e)
    {
        DrawFocus();
        base.OnMouseEnter(e);
    }

    protected override void OnMouseLeave(EventArgs e)
    {
        Invalidate();
        base.OnMouseLeave(e);
    }
    protected override void OnMouseDown(MouseEventArgs e)
    {
        state = ButtonState.Pushed;
        Invalidate();
        base.OnMouseDown(e);
    }
    protected override void OnMouseUp(MouseEventArgs e)
    {
        state = ButtonState.Normal;
        Invalidate();
        base.OnMouseUp(e);
    }