How to customize message box

Question

I am doing C# application, and I want to change the style of a message box. Is it possible or not?

Example: change button style, fore color, etc.

Answer 1

MessageBox::Show uses function from user32.dll, and its style is dependent on Windows, so you cannot change it like that, you have to create your own form

Answer 2

You can't restyle the default MessageBox as that's dependant on the current Windows OS theme, however you can easily create your own MessageBox. Just add a new form (i.e. MyNewMessageBox) to your project with these settings:

FormBorderStyle    FixedToolWindow
ShowInTaskBar      False
StartPosition      CenterScreen

To show it use myNewMessageBoxInstance.ShowDialog();. And add a label and buttons to your form, such as OK and Cancel and set their DialogResults appropriately, i.e. add a button to MyNewMessageBox and call it btnOK. Set the DialogResult property in the property window to DialogResult.OK. When that button is pressed it would return the OK result:

MyNewMessageBox myNewMessageBoxInstance = new MyNewMessageBox();
DialogResult result = myNewMessageBoxInstance.ShowDialog();
if (result == DialogResult.OK)
{
    // etc
}

It would be advisable to add your own Show method that takes the text and other options you require:

public DialogResult Show(string text, Color foreColour)
{
     lblText.Text = text;
     lblText.ForeColor = foreColour;
     return this.ShowDialog();
}

Answer 3

Here is the code needed to create your own message box:

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

namespace MyStuff
{
    public class MyLabel : Label
    {
        public static Label Set(string Text = "", Font Font = null, Color ForeColor = new Color(), Color BackColor = new Color())
        {
            Label l = new Label();
            l.Text = Text;
            l.Font = (Font == null) ? new Font("Calibri", 12) : Font;
            l.ForeColor = (ForeColor == new Color()) ? Color.Black : ForeColor;
            l.BackColor = (BackColor == new Color()) ? SystemColors.Control : BackColor;
            l.AutoSize = true;
            return l;
        }
    }
    public class MyButton : Button
    {
        public static Button Set(string Text = "", int Width = 102, int Height = 30, Font Font = null, Color ForeColor = new Color(), Color BackColor = new Color())
        {
            Button b = new Button();
            b.Text = Text;
            b.Width = Width;
            b.Height = Height;
            b.Font = (Font == null) ? new Font("Calibri", 12) : Font;
            b.ForeColor = (ForeColor == new Color()) ? Color.Black : ForeColor;
            b.BackColor = (BackColor == new Color()) ? SystemColors.Control : BackColor;
            b.UseVisualStyleBackColor = (b.BackColor == SystemColors.Control);
            return b;
        }
    }
    public class MyImage : PictureBox
    {
        public static PictureBox Set(string ImagePath = null, int Width = 60, int Height = 60)
        {
            PictureBox i = new PictureBox();
            if (ImagePath != null)
            {
                i.BackgroundImageLayout = ImageLayout.Zoom;
                i.Location = new Point(9, 9);
                i.Margin = new Padding(3, 3, 2, 3);
                i.Size = new Size(Width, Height);
                i.TabStop = false;
                i.Visible = true;
                i.BackgroundImage = Image.FromFile(ImagePath);
            }
            else
            {
                i.Visible = true;
                i.Size = new Size(0, 0);
            }
            return i;
        }
    }
    public partial class MyMessageBox : Form
    {
        private MyMessageBox()
        {
            this.panText = new FlowLayoutPanel();
            this.panButtons = new FlowLayoutPanel();
            this.SuspendLayout();
            // 
            // panText
            // 
            this.panText.Parent = this;
            this.panText.AutoScroll = true;
            this.panText.AutoSize = true;
            this.panText.AutoSizeMode = AutoSizeMode.GrowAndShrink;
            //this.panText.Location = new Point(90, 90);
            this.panText.Margin = new Padding(0);
            this.panText.MaximumSize = new Size(500, 300);
            this.panText.MinimumSize = new Size(108, 50);
            this.panText.Size = new Size(108, 50);
            // 
            // panButtons
            // 
            this.panButtons.AutoSize = true;
            this.panButtons.AutoSizeMode = AutoSizeMode.GrowAndShrink;
            this.panButtons.FlowDirection = FlowDirection.RightToLeft;
            this.panButtons.Location = new Point(89, 89);
            this.panButtons.Margin = new Padding(0);
            this.panButtons.MaximumSize = new Size(580, 150);
            this.panButtons.MinimumSize = new Size(108, 0);
            this.panButtons.Size = new Size(108, 35);
            // 
            // MyMessageBox
            // 
            this.AutoScaleDimensions = new SizeF(8F, 19F);
            this.AutoScaleMode = AutoScaleMode.Font;
            this.ClientSize = new Size(206, 133);
            this.Controls.Add(this.panButtons);
            this.Controls.Add(this.panText);
            this.Font = new Font("Calibri", 12F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(0)));
            this.FormBorderStyle = FormBorderStyle.FixedSingle;
            this.Margin = new Padding(4);
            this.MaximizeBox = false;
            this.MinimizeBox = false;
            this.MinimumSize = new Size(168, 132);
            this.Name = "MyMessageBox";
            this.ShowIcon = false;
            this.ShowInTaskbar = false;
            this.StartPosition = FormStartPosition.CenterScreen;
            this.ResumeLayout(false);
            this.PerformLayout();
        }
        public static string Show(Label Label, string Title = "", List<Button> Buttons = null, PictureBox Image = null)
        {
            List<Label> Labels = new List<Label>();
            Labels.Add(Label);
            return Show(Labels, Title, Buttons, Image);
        }
        public static string Show(string Label, string Title = "", List<Button> Buttons = null, PictureBox Image = null)
        {
            List<Label> Labels = new List<Label>();
            Labels.Add(MyLabel.Set(Label));
            return Show(Labels, Title, Buttons, Image);
        }
        public static string Show(List<Label> Labels = null, string Title = "", List<Button> Buttons = null, PictureBox Image = null)
        {
            if (Labels == null) Labels = new List<Label>();
            if (Labels.Count == 0) Labels.Add(MyLabel.Set(""));
            if (Buttons == null) Buttons = new List<Button>();
            if (Buttons.Count == 0) Buttons.Add(MyButton.Set("OK"));
            List<Button> buttons = new List<Button>(Buttons);
            buttons.Reverse();

            int ImageWidth = 0;
            int ImageHeight = 0;
            int LabelWidth = 0;
            int LabelHeight = 0;
            int ButtonWidth = 0;
            int ButtonHeight = 0;
            int TotalWidth = 0;
            int TotalHeight = 0;

            MyMessageBox mb = new MyMessageBox();

            mb.Text = Title;

            //Image
            if (Image != null)
            {
                mb.Controls.Add(Image);
                Image.MaximumSize = new Size(150, 300);
                ImageWidth = Image.Width + Image.Margin.Horizontal;
                ImageHeight = Image.Height + Image.Margin.Vertical;
            }

            //Labels
            List<int> il = new List<int>();
            mb.panText.Location = new Point(9 + ImageWidth, 9);
            foreach (Label l in Labels)
            {
                mb.panText.Controls.Add(l);
                l.Location = new Point(200, 50);
                l.MaximumSize = new Size(480, 2000);
                il.Add(l.Width);
            }
            int mw = Labels.Max(x => x.Width);
            il.ToString();
            Labels.ForEach(l => l.MinimumSize = new Size(Labels.Max(x => x.Width), 1));
            mb.panText.Height = Labels.Sum(l => l.Height);
            mb.panText.MinimumSize = new Size(Labels.Max(x => x.Width) + mb.ScrollBarWidth(Labels), ImageHeight);
            mb.panText.MaximumSize = new Size(Labels.Max(x => x.Width) + mb.ScrollBarWidth(Labels), 300);
            LabelWidth = mb.panText.Width;
            LabelHeight = mb.panText.Height;

            //Buttons
            foreach (Button b in buttons)
            {
                mb.panButtons.Controls.Add(b);
                b.Location = new Point(3, 3);
                b.TabIndex = Buttons.FindIndex(i => i.Text == b.Text);
                b.Click += new EventHandler(mb.Button_Click);
            }
            ButtonWidth = mb.panButtons.Width;
            ButtonHeight = mb.panButtons.Height;

            //Set Widths
            if (ButtonWidth > ImageWidth + LabelWidth)
            {
                Labels.ForEach(l => l.MinimumSize = new Size(ButtonWidth - ImageWidth - mb.ScrollBarWidth(Labels), 1));
                mb.panText.Height = Labels.Sum(l => l.Height);
                mb.panText.MinimumSize = new Size(Labels.Max(x => x.Width) + mb.ScrollBarWidth(Labels), ImageHeight);
                mb.panText.MaximumSize = new Size(Labels.Max(x => x.Width) + mb.ScrollBarWidth(Labels), 300);
                LabelWidth = mb.panText.Width;
                LabelHeight = mb.panText.Height;
            }
            TotalWidth = ImageWidth + LabelWidth;

            //Set Height
            TotalHeight = LabelHeight + ButtonHeight;

            mb.panButtons.Location = new Point(TotalWidth - ButtonWidth + 9, mb.panText.Location.Y + mb.panText.Height);

            mb.Size = new Size(TotalWidth + 25, TotalHeight + 47);
            mb.ShowDialog();
            return mb.Result;
        }

        private FlowLayoutPanel panText;
        private FlowLayoutPanel panButtons;
        private int ScrollBarWidth(List<Label> Labels)
        {
            return (Labels.Sum(l => l.Height) > 300) ? 23 : 6;
        }

        private void Button_Click(object sender, EventArgs e)
        {
            Result = ((Button)sender).Text;
            Close();
        }

        private string Result = "";
    }
}