How to set the Auto Size Mode of FlowLayoutPanel in C#?

In Windows Forms, FlowLayoutPanel control is used to arrange its child controls in a horizontal or vertical flow direction. Or in other words, FlowLayoutPanel is a container which is used to organize different or same types of controls in it either horizontally or vertically. In FlowLayoutPanel control, you can set a value which indicates how FlowLayoutPanel behaves when the value of the AutoSize Property is set to true, using AutoSizeMode Property. This property has two different values that are defined under AutoSizeMode enum and the values are:

• GrowOnly: This value indicates that the FlowLayoutPanel grow according to the content, but does not shrink if the content is less.
• GrowAndShrink: This value indicates the FlowLayoutPanel grows and shrink according to the content present in it.

The default value of this property is GrowOnly. You can set this property in two different ways:

1. Design-Time: It is the easiest way to set the AutoSizeMode property of the FlowLayoutPanel as shown in the following steps:

• Step 1: Create a windows form as shown in the below image:
  Visual Studio -> File -> New -> Project -> WindowsFormApp
  
• Step 2: Next, drag and drop the FlowLayoutPanel control from the toolbox to the form as shown in the below image:

  

• Step 3: After drag and drop you will go to the properties of the FlowLayoutPanel and set the AutoSizeMode property of the FlowLayoutPanel as shown in the below image:

  

  
  
  

  Output:
  

2. Run-Time: It is a little bit trickier than the above method. In this method, you can set the AutoSizeMode property of the FlowLayoutPanel control programmatically with the help of given syntax:

public virtual System.Windows.Forms.AutoSizeMode AutoSizeMode { get; set; }

Here, AutoSizeMode represents the size modes of the FlowLayoutPanel control. It will throw an InvalidEnumArgumentException if the value of this property does not belong to AutoSizeMode enum values. The following steps show how to set the AutoSizeMode property of the FlowLayoutPanel dynamically:

• Step 1: Create a FlowLayoutPanel using the FlowLayoutPanel() constructor is provided by the FlowLayoutPanel class.

  // Creating a FlowLayoutPanel
  FlowLayoutPanel f = new FlowLayoutPanel();
  

• Step 2: After creating FlowLayoutPanel, set the AutoSizeMode property of the FlowLayoutPanel provided by the FlowLayoutPanel class.

  // Setting the AutoSizeMode property
   f.AutoSizeMode = AutoSizeMode.GrowAndShrink;
  

• Step 3: And last add this FlowLayoutPanel control to the form and also adding child controls in the FlowLayoutPanel using the following statements:

  // Adding a FlowLayoutPanel
  // control to the form
  this.Controls.Add(f);
  
  and 
  
  // Adding child controls to
  // the FlowLayoutPanel
  f.Controls.Add(r1);
  

Example:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp50 {

public partial class Form1 : Form {

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        // Creating and setting the
        // properties of FlowLayoutPanel
        FlowLayoutPanel f = new FlowLayoutPanel();
        f.Location = new Point(380, 124);
        f.AutoSize = true;
        f.AutoSizeMode = AutoSizeMode.GrowAndShrink;
        f.Name = "Mycontainer";
        f.Font = new Font("Calibri", 12);
        f.FlowDirection = FlowDirection.RightToLeft;
        f.BorderStyle = BorderStyle.Fixed3D;
        f.ForeColor = Color.BlueViolet;
        f.BackColor = Color.LightPink;
        f.Visible = true;

        // Adding this control to the form
        this.Controls.Add(f);

        // Creating and setting the
        // properties of radio buttons
        RadioButton r1 = new RadioButton();
        r1.Location = new Point(3, 3);
        r1.Size = new Size(95, 20);
        r1.Text = "R1";

        // Adding this control
        // to the FlowLayoutPanel
        f.Controls.Add(r1);

        RadioButton r2 = new RadioButton();
        r2.Location = new Point(94, 3);
        r2.Size = new Size(95, 20);
        r2.Text = "R2";

        // Adding this control
        // to the FlowLayoutPanel
        f.Controls.Add(r2);

        RadioButton r3 = new RadioButton();
        r3.Location = new Point(3, 26);
        r3.Size = new Size(95, 20);
        r3.Text = "R3";

        // Adding this control
        // to the FlowLayoutPanel
        f.Controls.Add(r3);
    }
}
}

Output: