如何在用户选择控件时使 OnPaint 运行 具有不同的 ControlPaint.DrawBorderStyle 功能

Question

我有一个具有以下 onPaint 方法的用户控件（Groupbox）：

protected override void OnPaint(PaintEventArgs e) {
    Size tSize = TextRenderer.MeasureText(this.Text, this.Font);
    Rectangle borderRect = e.ClipRectangle;
    borderRect.Y += tSize.Height / 2;
    borderRect.Height -= tSize.Height / 2;
    ControlPaint.DrawBorder(e.Graphics, borderRect, this.borderColor, ButtonBorderStyle.Solid);

    Rectangle textRect = e.ClipRectangle;
    textRect.X += 6;
    textRect.Width = tSize.Width;
    textRect.Height = tSize.Height;
    e.Graphics.FillRectangle(new SolidBrush(this.BackColor), textRect);
    e.Graphics.DrawString(this.Text, this.Font, new SolidBrush(this.ForeColor), textRect);
}

当用户select使用这个控件时，我想把边框改得更深一些，所以我尝试了以下逻辑：

protected override void OnPaint(PaintEventArgs e) {
    Size tSize = TextRenderer.MeasureText(this.Text, this.Font);
    Rectangle borderRect = e.ClipRectangle;
    borderRect.Y += tSize.Height / 2;
    borderRect.Height -= tSize.Height / 2;
    if (ContainsFocus) {
        ControlPaint.DrawBorder(e.Graphics, borderRect,
            this.borderColor, 4, ButtonBorderStyle.Solid,
            this.borderColor, 4, ButtonBorderStyle.Solid,
            this.borderColor, 4, ButtonBorderStyle.Solid,
            this.borderColor, 4, ButtonBorderStyle.Solid);
    } else {
        ControlPaint.DrawBorder(e.Graphics, borderRect, this.borderColor, ButtonBorderStyle.Solid);
    }

    Rectangle textRect = e.ClipRectangle;
    textRect.X += 6;
    textRect.Width = tSize.Width;
    textRect.Height = tSize.Height;
    e.Graphics.FillRectangle(new SolidBrush(this.BackColor), textRect);
    e.Graphics.DrawString(this.Text, this.Font, new SolidBrush(this.ForeColor), textRect);
}

即使我 select 我的用户控件，我的控件似乎也在不断地进入 else。在这方面的任何帮助将不胜感激。

Answer 1

为了解决这个问题，我使用了 onMouseClick 事件，结合声明一个构造函数，该构造函数将初始 borderColor 设置为不同的值.像这样

    private Color borderColor;
    private int entered;

    public TUserControlGroupBox() {
        this.borderColor = SystemColors.ControlDark;
    }

    public Color BorderColor {
        get { return this.borderColor; }
        set { this.borderColor = value; }
    }

    public BorderState Border {
        set {
            switch (value) {
                case BorderState.Unselected:
                    this.BorderColor = Color.LightGray;
                    break;
                case BorderState.Selected:
                    this.BorderColor = Color.Black;
                    break;
                case BorderState.SelectedFirst:
                    this.BorderColor = SystemColors.ControlDark;
                    break;
            }

            this.Invalidate();
        }
    }

    protected override void OnPaint(PaintEventArgs e) {
        Size tSize = TextRenderer.MeasureText(this.Text, this.Font);
        Rectangle borderRect = e.ClipRectangle;
        borderRect.Y += tSize.Height / 2;
        borderRect.Height -= tSize.Height / 2;
        if ((this.BorderColor == Color.Black || this.borderColor == SystemColors.ControlDark) && this.entered == 1) {
            ControlPaint.DrawBorder(e.Graphics, borderRect,
                this.borderColor, 4, ButtonBorderStyle.Solid,
                this.borderColor, 4, ButtonBorderStyle.Solid,
                this.borderColor, 4, ButtonBorderStyle.Solid,
                this.borderColor, 4, ButtonBorderStyle.Solid);
        } else {
            ControlPaint.DrawBorder(e.Graphics, borderRect, this.borderColor, ButtonBorderStyle.Solid);
        }
        Rectangle textRect = e.ClipRectangle;
        textRect.X += 6;
        textRect.Width = tSize.Width;
        textRect.Height = tSize.Height;
        e.Graphics.FillRectangle(new SolidBrush(this.BackColor), textRect);
        e.Graphics.DrawString(this.Text, this.Font, new SolidBrush(this.ForeColor), textRect);
    }

    protected override void OnMouseClick(MouseEventArgs e) {
        this.entered = 1;
        this.Invalidate();
        base.OnMouseClick(e);
    }

希望这个答案对那些在未来寻找类似解决方案的人有所帮助。