'AutoSize=true' panel height not adjusting when labels become multiline

Question

I'm currently facing an issue with a panel in my C# WinForms application. The panel is docked at the top of the form with AutoSize set to True. Within this panel, I have a TableLayoutPanel also with AutoSize set to True and Fill docking. This TableLayoutPanel contains two rows, each with a label that fills the row and is also set to AutoSize.

The problem arises when the labels within the TableLayoutPanel become multiline. Despite setting AutoSize to True for both the TableLayoutPanel and its rows, the panel's height does not adjust accordingly when the labels wrap to multiple lines.

Here's a summary of my setup:

Panel docked at the top of the form with AutoSize=True. TableLayoutPanel inside the panel with AutoSize=True and Fill docking. Two rows within the TableLayoutPanel, each containing a label with AutoSize=True. However, when the labels in the TableLayoutPanel become multiline, the panel's height remains static and does not adjust to accommodate the multiline labels.

I've tried several approaches, including adjusting the AutoSize and AutoSizeMode properties of both the panel and the TableLayoutPanel, but I haven't been able to resolve the issue.

Does anyone have any insights or suggestions on how to make the panel adjust its height dynamically when the labels within the TableLayoutPanel become multiline?

To reproduce the issue:

1. Create a new C# WinForms project.
2. Add an empty form to the project.
3. Replace the designer-generated code for the form with the provided code snippet below.
4. Change the width of the form to make labels wrap text and became multiline.

    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            panel1 = new Panel();
            tableLayoutPanel1 = new TableLayoutPanel();
            label2 = new Label();
            label1 = new Label();
            panel1.SuspendLayout();
            tableLayoutPanel1.SuspendLayout();
            SuspendLayout();
            // 
            // panel1
            // 
            panel1.AutoSize = true;
            panel1.AutoSizeMode = AutoSizeMode.GrowAndShrink;
            panel1.Controls.Add(tableLayoutPanel1);
            panel1.Dock = DockStyle.Top;
            panel1.Location = new Point(100, 100);
            panel1.Name = "panel1";
            panel1.Padding = new Padding(3);
            panel1.Size = new Size(540, 98);
            panel1.TabIndex = 0;
            // 
            // tableLayoutPanel1
            // 
            tableLayoutPanel1.AutoSize = true;
            tableLayoutPanel1.AutoSizeMode = AutoSizeMode.GrowAndShrink;
            tableLayoutPanel1.BackColor = SystemColors.ControlDark;
            tableLayoutPanel1.ColumnCount = 1;
            tableLayoutPanel1.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 100F));
            tableLayoutPanel1.Controls.Add(label2, 0, 1);
            tableLayoutPanel1.Controls.Add(label1, 0, 0);
            tableLayoutPanel1.Dock = DockStyle.Fill;
            tableLayoutPanel1.Location = new Point(3, 3);
            tableLayoutPanel1.Name = "tableLayoutPanel1";
            tableLayoutPanel1.RowCount = 3;
            tableLayoutPanel1.RowStyles.Add(new RowStyle());
            tableLayoutPanel1.RowStyles.Add(new RowStyle());
            tableLayoutPanel1.RowStyles.Add(new RowStyle(SizeType.Absolute, 50F));
            tableLayoutPanel1.Size = new Size(534, 92);
            tableLayoutPanel1.TabIndex = 0;
            // 
            // label2
            // 
            label2.AutoSize = true;
            label2.BackColor = Color.Chartreuse;
            label2.Dock = DockStyle.Fill;
            label2.Location = new Point(3, 24);
            label2.Margin = new Padding(3);
            label2.Name = "label2";
            label2.Size = new Size(528, 15);
            label2.TabIndex = 3;
            label2.Text = "asd asd asd as das das dasd as ddas";
            label2.TextAlign = ContentAlignment.MiddleCenter;
            // 
            // label1
            // 
            label1.AutoSize = true;
            label1.BackColor = Color.Coral;
            label1.Dock = DockStyle.Fill;
            label1.Location = new Point(3, 3);
            label1.Margin = new Padding(3);
            label1.Name = "label1";
            label1.Size = new Size(528, 15);
            label1.TabIndex = 2;
            label1.Text = "dasdasdsa";
            label1.TextAlign = ContentAlignment.MiddleCenter;
            // 
            // Form2
            // 
            AutoScaleDimensions = new SizeF(7F, 15F);
            AutoScaleMode = AutoScaleMode.Font;
            ClientSize = new Size(740, 525);
            Controls.Add(panel1);
            Name = "Form2";
            Padding = new Padding(100);
            Text = "Form2";
            panel1.ResumeLayout(false);
            panel1.PerformLayout();
            tableLayoutPanel1.ResumeLayout(false);
            tableLayoutPanel1.PerformLayout();
            ResumeLayout(false);
            PerformLayout();
        }

        #endregion

        private Panel panel1;
        private TableLayoutPanel tableLayoutPanel1;
        private Label label2;
        private Label label1;
    }

Answer 1

Don't use panel1. Instead, set tableLayoutPanel1.Dock = DockStyle.Top; and add it directly to the Form. Also, remove the 3rd row (this will remove the empty gray area).

---

Another solution is to calculate the height of the panels in a resize event handler and to set them "manually":

private void TableLayoutPanel1_Resize(object sender, EventArgs e)
{
    int height = 12;
    foreach (Control c in tableLayoutPanel1.Controls) {
        height += c.Height;
    }
    height = Math.Max(92, height);
    tableLayoutPanel1.Height = height;
    panel1.Height = height + 6;
}