请教自定义控件的问题

leon51 2019-08-12 09:49:11

想制作一个自定义控件，我现在是用多个.net本身的控件，比较麻烦。自定义控件包含一个button,一个Lable，一个Line，两个panel(pnlTitle和pnlContent),
功能很简单：点击按钮时，隐藏或显示下方的pnlContent,自定义控件整体高度随之调整

我用以下代码无法添加直线，请问要怎么修改？

public CollapsiblePanel()

{

	InitializeComponent();

	this.Paint += CollapsiblePanel_Paint;

}



private void CollapsiblePanel_Paint(object sender, PaintEventArgs e)

{

	base.OnPaint(e);	

	Graphics graphics = this.CreateGraphics();

	Pen pen = new Pen(Color.Red, 2);

	Point startPoint = new Point(10, 10);

	Point endPoint = new Point(50, 10);

	graphics.DrawLine(pen, startPoint, endPoint);

	pen.Dispose();

	graphics.Dispose();

}

单击按钮时隐藏或显示pnlContent，控件高度相应调整，但下面代码高度无法恢复

private void btnCollapse_Click(object sender, EventArgs e)

{

	if (btnCollapse.Text == "+")

	{

		btnCollapse.Text = "-";

		pnlContent.Visible = true;

		this.Height += pnlContent.Height;//此处应该如何修改？

	}

	else if (btnCollapse.Text == "-")

	{

		btnCollapse.Text = "+";

		pnlContent.Visible = false;

		this.Height -= pnlContent.Height;

	}

}