Thank you very much for you reply!
According to you reply, I modified my codes, and it can draw line. However,
I want to make it draw line dynamically when the mouse is moving. But the
application can only draw a static line when it starts. I paste my related
code as below, please have a look at it if you have a second. I do not know
how to use the MDIParent Function in you code. I think it may be the reason.
Thank you in advance.
class MyApplicationContext : ApplicationContext
{
private int formCount;
private Form1 mainform, subform1,subform2;
private var tvar = new var();
MdiClient client = null;
private int currx=0;
private int curry=0;
public MyApplicationContext()
{
formCount = 0;
// Handle the ApplicationExit event to know when the application
is exiting.
mainform = new Form1();
mainform.SetBounds(0, 0, 1280, 800);
mainform.IsMdiContainer=true;
foreach (Control c in mainform.Controls)
{
if (c is MdiClient)
client = (MdiClient)c;
}
client.Paint += new PaintEventHandler(client_Paint);
subform1 = new Form1();
subform1.Closed += new EventHandler(OnFormClosed);
subform1.SetDesktopLocation(50, 100);
subform1.changeText("Start");
subform1.buttonShow();
formCount++;
subform2 = new Form1();
subform2.Closed += new EventHandler(OnFormClosed);
subform2.SetDesktopLocation(600,100);
subform2.changeText("Stop");
subform2.buttonShow();
formCount++;
subform1.MdiParent = mainform;
subform2.MdiParent = mainform;
// Show both forms.
mainform.Show();
mainform.MouseMove += new MouseEventHandler(Form_Move);
mainform.MouseHover += new EventHandler(Form_Move2);
subform1.Show();
subform2.Show();
}
void client_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawLine(Pens.Red,200,300,currx,curry);
}
void Form_Move(object sender, MouseEventArgs e)
{
currx = Control.MousePosition.X;
curry = Control.MousePosition.Y;
client.Invalidate();
}
void Form_Move2(object sender, EventArgs e)
{
currx = Control.MousePosition.X;
curry = Control.MousePosition.Y;
client.Invalidate();
}
private void OnFormClosed(object sender, EventArgs e)
{
// When a form is closed, decrement the count of open forms.
// When the count gets to 0, exit the app by calling
// ExitThread().
formCount--;
if (formCount == 0)
{
tvar.close();
ExitThread();
}
}
}
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
MyApplicationContext context = new MyApplicationContext();
Application.Run(context);
}
}
Sorry about that,
When you set a Form to IsMdiContainer = true you also create an MdiClient
control which is added to the form. This control is the gray background you
see. You need to subscribe to the MdiClient's Paint event and draw in the
client surface.
The code below will draw a line between the upper left corner of the
MdiParent and an MdiChild
MdiClient client = null;
Form1 f = new Form1();
public MDIParent()
{
InitializeComponent();
foreach (Control c in this.Controls)
{
if (c is MdiClient)
client = (MdiClient)c;
}
client.Paint += new PaintEventHandler(client_Paint);
f.MdiParent = this;
f.Show();
f.Move += new EventHandler(f_Move);
}
void client_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawLine(Pens.Black, new Point(0, 0), f.Location);
}
void f_Move(object sender, EventArgs e)
{
client.Invalidate();
}
Hi, Morten,
I declare 3 forms, and set the mainform as
mainform.IsMdiContainer=true;
to make it can contain subform1 and subform2.However, It looks like a line
can not be drawn in a form which is a MDI container.I can only draw lines
in
subform1 and subform2 by using Form_Paint event. Do you have any comments
about this? Thank you !
