Question

I am new to windows application. with C# and .NET.
I want something like the image i have attach. when my popup gets open, i want the mdi parent page to be shadowed or disbaled. (like we do in web application or Jquery popup)

Is it possible to do? if yes how can i do that.

Please help.

Answer 1

You can Achive this by making use of the opacity property of the Windows.Form
For this create a new form, sets its opacity (for eg: .75) and show this over the parent for when ever you are showing a child window.
An Example is given Below

There are three windows used here
1. ParentForm
2. OverlayForm
3. ChildForm

1. Parent Form

1. Create an instance of the Child form 
2. Create an Instance of the Overlayform, Pass the objects Instances of Child and Parent(current form) as a parameter to the Constructor
3. Then Show the OverLay Form by using  ShowDialog Method.

Code:

public partial class ParentForm : Form
{
    public ParentForm()
    {

        InitializeComponent();
    }

    private void ParentForm_Load(object sender, EventArgs e)
    {

    }

    private void button1_Click(object sender, EventArgs e)
    {
        ChildForm child1 = new ChildForm();
        // Create a new form.
        OverlayForm form2 = new OverlayForm(this, child1);
        child1.OverLay = form2;
        // Display the form as a modal dialog box.
        form2.ShowDialog(this);
    }
}

2. Overlay Form

1. In the constructor store the childForm and ParentForm object in a local variables. 
       And Set the The properties (like width,height) to the Overlay Window
    2. In the OverlayForm_Load show the ChildForm window.

public partial class OverlayForm : Form
{
    public Form ParentForm { get; set; }
    public Form child { get; set; }
    public OverlayForm(Form parent, Form child)
    {
        InitializeComponent();
        this.child = child;
        this.ParentForm = parent;

        this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
        this.ShowInTaskbar = false;
        this.Width = ParentForm.Width;
        this.Height = ParentForm.Height;
        this.Top = ParentForm.Top;
        this.Left = ParentForm.Left;
        this.StartPosition = ParentForm.StartPosition;
        // Set the opacity to 75%.
        this.Opacity = .75;
    }

    private void OverlayForm_Load(object sender, EventArgs e)
    {
        child.Show();
        child.TopMost = true;
        child.Focus();
        child.BringToFront();
    }
}

This will give the parent form a blur look. We should also write some code to close the overlay in the Child Form

3. Child Form

1. Set the object of the Overlay  to a property in Child Window
2. And in the Form_Closing event of the child window, close the Overlay window.

public partial class ChildForm : Form
{
    //This is set in the Parent form where the child form instatce is created
    public Form OverLay { get; set; }
    public ChildForm()
    {
        InitializeComponent();
    }

    private void ChildForm_Load(object sender, EventArgs e)
    {
    }

    private void ChildForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        this.OverLay.Close();
    }
}