How to owner draw a TreeView Node to show two lines of text-CodePudding

I am trying to figure out a way to use the StringFormat class to add new line to a given TreeNode text. For example, the string ID1:123456, ID2:789000, can be split by comma and insert a newline in between, so it has two lines.

I understand there is no need to make a TreeNode text into multiple lines, but this is required by my supervisor and I have no choice.

My current solution is to override a DrawNode function, and use the DrawString function to customize TreeNode text format, but my question is I don't know how to insert newline at this stage.

private void TreeView_SO_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
        e.DrawDefault = false;
        string drawString = e.Node.Text;
        Font drawFont = ((TreeView)sender).Font;
        SolidBrush drawBrush = new SolidBrush(Color.Black);

        StringFormat drawFormat = new StringFormat();
        // what to put in here to insert a new line?

        e.Graphics.DrawString(drawString, drawFont, drawBrush, e.Node.Bounds, drawFormat);

}

Update

Thank you for everyone's help. I ended up finding this is quite easy, thanks to EskeRahn's codes posted on: WINDOWS TREEVIEW WITH E.G. MULTI-LINE TREE CONTENT. This code is quite useful; however, I only need part of EskeRnhn's code to perform my ideal operation. So my code ended up like this,

private void TreeView_SO_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
            e.DrawDefault = false;
            string drawString = e.Node.Text;
            Font drawFont = ((TreeView)sender).Font;
            SolidBrush drawBrush = new SolidBrush(Color.Black);
            Rectangle eNodeBounds = NodeBounds(e.Node);

            e.Graphics.DrawString(drawString, drawFont, drawBrush, eNodeBounds);
}

private Rectangle NodeBounds(TreeNode node)
{
    if (node?.TreeView != null && node?.Text != null && (0 < node.Bounds.Location.X || 0 < node.Bounds.Location.Y))
    {
        using (Graphics g = node.TreeView.CreateGraphics())
        {
            SizeF textSize = g.MeasureString(node.Text, node.NodeFont ?? node.TreeView.Font);
            return Rectangle.Ceiling(new RectangleF(PointF.Add(node.Bounds.Location,
                                     new SizeF(0, (node.TreeView.ItemHeight - textSize.Height) / 2)),
                                     textSize));
        }
    }
    else
    {
        return node?.Bounds ?? new Rectangle();
    }
}

, where I don't need to worry about the the StringFormat class at all, because I already override the a DrawNode function, so when I pass the string to TreeNode text, I just need to add newline symbols. I have tested multiple cases and this piece of code works well.

CodePudding user response：

You can split the text by comma, and then join using new line.

var splitText = e.Node.Text.Split(new char[] { ',' }, System.StringSplitOptions.RemoveEmptyEntries);
var newString = string.Join(System.Environment.NewLine, splitText);