Well, I noticed that. hence, I've worked on it. and here is the result.
Set IsMdiContainer property of your parent form to value false. then , replace form_load event handler as following:
<br />
private void Form1_Load(object sender, EventArgs e)<br />
{<br />
this.TransparencyKey = Color.FromArgb(255, 220, 33, 55);<br />
<br />
MdiClient Client = new MdiClient();<br />
<br />
this.Controls.Add(Client);<br />
<br />
Form Child = new Form();<br />
<br />
Child.Size = new Size(100, 100);<br />
Child.FormBorderStyle = FormBorderStyle.FixedDialog;<br />
Child.StartPosition = FormStartPosition.CenterParent;<br />
Child.MaximizeBox = false;<br />
Child.MinimizeBox = false;<br />
<br />
Child.MdiParent = this;<br />
this.pictureBox1.Controls.Add(Child);<br />
<br />
Child.Show(); <br />
}<br />
this code, will do transparency, and will add the mdiclient and child form. everything works fine, just, as you can see, childe form can be moved over all the parent form area. hence, the last TODO is finding a way to prevent it from being moved over transparented areas.
I'll work on that too, as soon as possible.
hope this helps.
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Regards
H.Maadani