Non draggable windows form

Question

I am using c# language with windows form. I open the child form on top of the main windows form. Is there a simple way to turn off the draggable feature in both forms? Or is it possible to move it at the same time as the main form?

Amit Mohanty · Answer

Hey Mehmet Fatih, add the WndProc method in code behond file of your child forms.

Amit Mohanty · Answer

Use below function in your child form to non draggable. protected override void WndProc(ref Message m) { const int WM_NCLBUTTONDOWN = 161; const int WM_SYSCOMMAND = 274; const int HTCAPTION = 2; const int SC_MOVE = 61456; if ((m.Msg == WM_SYSCOMMAND) && (m.WParam.ToInt32() == SC_MOVE)) { return; } if ((m.Msg == WM_NCLBUTTONDOWN) && (m.WParam.ToInt32() == HTCAPTION)) { return; } base.WndProc(ref m); }

Sam Hobbs · Answer

I assume you are not using MDI but if you are then please say so. If the following does not apply then you probably need to be more specific about what you are doing. Is the child form owned by the main form? When you show the form are you using Show() or Show(this) ?

Mehmet Fatih · Answer

Thanks Amit.

Mehmet Fatih · Answer

Thanks Amit. How can we add reference to it?

Sam Hobbs · Answer

No, the child form is not owned by the main form. You need to use frm.ShowDialog(); to get the child form owned by the main form. Or you can use the Owner property. However that is not likely to solve the problem. MDI is called Multiple- Document Interface . It is designed to support multiple documents , not multiple windows. When MDI is used for multiple general-purpose windows there are problems. See the following article. C# Create Child Forms | coding.vision https://codingvision.net/c-create-child-forms You can start with that and modify it as needed. The following shows the code from that article with some modifications. The commented out portions are suggestions, you can choose one of the values for `FormBorderStyle`. Since you are not specific with the requirements I cannot be specific with a solution. Form2 frm = new Form2(); frm.TopLevel = false; Controls.Add(frm); //frm.FormBorderStyle = FormBorderStyle.None; //frm.FormBorderStyle = FormBorderStyle.FixedToolWindow; //frm.FormBorderStyle = FormBorderStyle.FixedSingle; frm.StartPosition = FormStartPosition.Manual; frm.Location = new Point(50, 50); frm.Show(); frm.BringToFront();

Mehmet Fatih · Answer

Thanks for your intrest Sam. Yes, the child form is owned by the main form. I am using it like that VeliGorusmeF frm = new VeliGorusmeF(); frm.ShowDialog(); I am using MDI but I am openeing the child forms over the main form not inside it.

Sam Hobbs · Answer

Read the cocumentation. There are values you can use for FormBorderStyle . I was not sure what you meant by not draggable. I could not be sure that you meant that you wanted the child form to not be draggable outside the main form.

Mehmet Fatih · Answer

Thank you Sam. I had tried it before but it didn't solve the problem. The child form is still draggable.