Disable Background for popup like asp.net ajax

[Won]

Is it possible that making background look dark and not being able to click when there is a popup window from grid like asp.net ajax does?

[Emanuel Varga]

Hello Won,

Sorry, but transparency (opacity) is not supported in Winforms (for anything other than for the form themselves), but you could "fake" this behavior by doing the following:
1 Creating a control that will have a PictureBox where the snapshot of your running form will be.
2. Add that control to your form docked
3. Call a ShowMessageBox method (from within your control)
4 This will Take a snapshot of your form and attach it to the picturebox, and using a timer will create a fading efect.
5. Show the message box
6. Close the messagebox and revert to original

And following, i have created an application to test this ( i was meaning to for a while now, and now i had some free time to play around with some things)

using System.Windows.Forms;

namespace TestDarkenMessageBox
{
    using System.Drawing;
    using System.Drawing.Imaging;
    using Telerik.WinControls;
    using Telerik.WinControls.UI;

    public partial class Form1 : Form
    {
        private RadDarkenControl darkenControl;

        public Form1()
        {
            InitializeComponent();
            this.Load += new System.EventHandler(Form1_Load);
        }

        void button_Click(object sender, System.EventArgs e)
        {
            darkenControl.ShowMessageBox("BOO!");
        }

        void Form1_Load(object sender, System.EventArgs e)
        {
            var button = new RadButton();
            button.Text = "Show MessageBox";
            button.Click += new System.EventHandler(button_Click);
            this.Controls.Add(button);

            button = new RadButton();
            button.Text = "Test";
            button.Click += new System.EventHandler(button_Click);
            button.Dock = DockStyle.Bottom;
            this.Controls.Add(button);

            button = new RadButton();
            button.Text = "Test2";
            button.Click += new System.EventHandler(button_Click);
            button.Dock = DockStyle.Bottom;
            this.Controls.Add(button);

            darkenControl = new RadDarkenControl(this);
            darkenControl.Size = this.Size;
            darkenControl.Anchor = AnchorStyles.Left | AnchorStyles.Right | AnchorStyles.Top | AnchorStyles.Bottom;
            this.Controls.Add(darkenControl);
        }
    }

    public class RadDarkenControl : RadControl
    {
        private Form parent;

        private PictureBox darkenedForm = new PictureBox();

        private int minimumBrightness = -30;

        private int brightness = 0;

        public RadDarkenControl(Form parentForm)
        {
            InitializeComponent();
            this.parent = parentForm;
            this.Visible = false;
            this.Controls.Add(darkenedForm);
            darkenedForm.Dock = DockStyle.Fill;
        }

        private void ShowControl()
        {
            brightness = 0;

            this.Visible = true;

            var formSnapshot = this.CaptureControl(parent);
            darkenedForm.Image = AdjustBrightness(formSnapshot, brightness);
            darkenedForm.BringToFront();
            this.BringToFront();
            var timer = new Timer();
            timer.Tick += new System.EventHandler(timer_Tick);
            timer.Interval = 20;
            timer.Start();
        }

        void timer_Tick(object sender, System.EventArgs e)
        {
            if (brightness > minimumBrightness)
            {
                darkenedForm.Image = AdjustBrightness((Bitmap)darkenedForm.Image, brightness);
                brightness -= 5;
            }
        }

        private Bitmap CaptureControl(Form form)
        {
            var borderWidth = (parent.Width - parent.ClientSize.Width) / 2;
            var titlebarHeight = parent.Height - parent.ClientSize.Height - borderWidth;

            Graphics myGraphics = this.CreateGraphics();
            Size s = form.Size;
            var memoryImage = new Bitmap(s.Width - borderWidth, s.Height - titlebarHeight, myGraphics);
            Graphics memoryGraphics = Graphics.FromImage(memoryImage);
            memoryGraphics.CopyFromScreen(
                form.Location.X + borderWidth, form.Location.Y + titlebarHeight, 0, 0, s);

            return memoryImage;
        }

        private void HideControl()
        {
            this.Visible = false;
        }

        public void ShowMessageBox(string text)
        {
            this.ShowControl();
            MessageBox.Show(text);
            this.HideControl();
        }

        public static Bitmap AdjustBrightness(Bitmap Image, int Value)
        {
            System.Drawing.Bitmap TempBitmap = Image;
            float FinalValue = (float)Value / 255.0f;
            System.Drawing.Bitmap NewBitmap = new System.Drawing.Bitmap(TempBitmap.Width, TempBitmap.Height);
            System.Drawing.Graphics NewGraphics = System.Drawing.Graphics.FromImage(NewBitmap);
            float[][] FloatColorMatrix ={
                     new float[] {1, 0, 0, 0, 0},
                     new float[] {0, 1, 0, 0, 0},
                     new float[] {0, 0, 1, 0, 0},
                     new float[] {0, 0, 0, 1, 0},
                     new float[] {FinalValue, FinalValue, FinalValue, 1, 1}
                 };

            System.Drawing.Imaging.ColorMatrix NewColorMatrix = new System.Drawing.Imaging.ColorMatrix(FloatColorMatrix);
            System.Drawing.Imaging.ImageAttributes Attributes = new System.Drawing.Imaging.ImageAttributes();
            Attributes.SetColorMatrix(NewColorMatrix);
            NewGraphics.DrawImage(TempBitmap, new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), 0, 0, TempBitmap.Width, TempBitmap.Height, System.Drawing.GraphicsUnit.Pixel, Attributes);
            Attributes.Dispose();
            NewGraphics.Dispose();
            return NewBitmap;
        }

        public static Bitmap AdjustContrast(Bitmap Image, float Value)
        {
            Value = (100.0f + Value) / 100.0f;
            Value *= Value;
            System.Drawing.Bitmap TempBitmap = Image;
            System.Drawing.Bitmap NewBitmap = new System.Drawing.Bitmap(TempBitmap.Width, TempBitmap.Height);
            System.Drawing.Graphics NewGraphics = System.Drawing.Graphics.FromImage(NewBitmap);
            NewGraphics.DrawImage(TempBitmap, new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), System.Drawing.GraphicsUnit.Pixel);
            NewGraphics.Dispose();

            for (int x = 0; x < NewBitmap.Width; ++x)
            {
                for (int y = 0; y < NewBitmap.Height; ++y)
                {
                    Color Pixel = NewBitmap.GetPixel(x, y);
                    float Red = Pixel.R / 255.0f;
                    float Green = Pixel.G / 255.0f;
                    float Blue = Pixel.B / 255.0f;
                    Red = (((Red - 0.5f) * Value) + 0.5f) * 255.0f;
                    Green = (((Green - 0.5f) * Value) + 0.5f) * 255.0f;
                    Blue = (((Blue - 0.5f) * Value) + 0.5f) * 255.0f;
                    NewBitmap.SetPixel(x, y, Color.FromArgb(Clamp((int)Red, 255, 0), Clamp((int)Green, 255, 0), Clamp((int)Blue, 255, 0)));
                }
            }

            return NewBitmap;
        }

        public static Bitmap AdjustGamma(Bitmap Image, float Value)
        {
            System.Drawing.Bitmap TempBitmap = Image;
            System.Drawing.Bitmap NewBitmap = new System.Drawing.Bitmap(TempBitmap.Width, TempBitmap.Height);
            System.Drawing.Graphics NewGraphics = System.Drawing.Graphics.FromImage(NewBitmap);
            NewGraphics.DrawImage(TempBitmap, new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), System.Drawing.GraphicsUnit.Pixel);
            NewGraphics.Dispose();

            int[] RedRamp = new int[256];
            int[] GreenRamp = new int[256];
            int[] BlueRamp = new int[256];
            for (int x = 0; x < 256; ++x)
            {
                RedRamp[x] = Clamp((int)((255.0 * System.Math.Pow(x / 255.0, 1.0 / Value)) + 0.5), 255, 0);
                GreenRamp[x] = Clamp((int)((255.0 * System.Math.Pow(x / 255.0, 1.0 / Value)) + 0.5), 255, 0);
                BlueRamp[x] = Clamp((int)((255.0 * System.Math.Pow(x / 255.0, 1.0 / Value)) + 0.5), 255, 0);
            }

            for (int x = 0; x < NewBitmap.Width; ++x)
            {
                for (int y = 0; y < NewBitmap.Height; ++y)
                {
                    Color Pixel = NewBitmap.GetPixel(x, y);
                    int Red = RedRamp[Pixel.R];
                    int Green = GreenRamp[Pixel.G];
                    int Blue = BlueRamp[Pixel.B];
                    NewBitmap.SetPixel(x, y, Color.FromArgb(Red, Green, Blue));
                }
            }

            return NewBitmap;
        }

        private static int Clamp(int Value, int Max, int Min)
        {
            Value = Value > Max ? Max : Value;
            Value = Value < Min ? Min : Value;
            return Value;
        }

        /// <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);
        }

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            ((System.ComponentModel.ISupportInitialize)(this)).BeginInit();
            this.SuspendLayout();
            //
            // RadDarkenControl
            //
            this.ClientSize = new System.Drawing.Size(298, 279);
            this.Name = "RadDarkenControl";
            this.Text = "RadDarkenControl";
            this.ThemeName = "ControlDefault";
            ((System.ComponentModel.ISupportInitialize)(this)).EndInit();
            this.ResumeLayout(false);
        }
    }
}

*Update, if you want a proof of concept for displaying a form from this you could just create a new method like this:

public void ShowSomeForm(Form form)
{
    this.ShowControl();
    form.FormClosing += new FormClosingEventHandler(form_FormClosing);
    form.Show();
}

void form_FormClosing(object sender, FormClosingEventArgs e)
{
    this.HideControl();
}

This will open the new form, NOT as a modal dialog, and because there is a picturebox on top of the form you cannot click on any of the controls inside the main form while this dialog is open.

It's just a basic example, but if you really want to, it should get you started.

Have fun!

Best Regards,
Emanuel Varga