32.30 How can I make sure I don't open a second instance modeless dialog that is already opened from my main form One way to do this is to maintain a list of opened modeless dialogs, and check this list before you open a new one to see if one is already present.If you open all these modeless dialog's from the same 'main' form, then you can use the OwnedForms property of that main form to maintain this list of opened dialogs. Below are some code snippets that suggest how you must go about this. Note that your dialog forms need to be able to turn off the ownership. This is done below by adding an Owner field to the dialog form.
//sample code that either opens a new dialog or displays an already opened dialog
//sample code that either opens a new dialog or displays an already opened dialog
private void button1_Click(object sender, System.EventArgs e)
{
foreach ( Form f in this.OwnedForms )
{
if (f is Form2)
{
f.Show();
f.Focus();
return;
}
}
//need a new one
Form2 f2 = new Form2();
this.AddOwnedForm(f2);
f2.Owner = this;
f2.Show();
}
//code for form2
public class Form2 : System.Windows.Forms.Form
{
private System.Windows.Forms.Label label1;
public Form Owner;
.......
.......
private void Form2_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
Owner.RemoveOwnedForm(this);
}
}
欢迎高手!
我试了一下.如果在一个窗体上点两下,是不会出现两个窗体的.但是如果有两个地方都调用了 同一个窗体,这招就不灵了.