How to prevent several forms to be displayed

[Tony Johansson]

Hello!

My start form that is run from Program ccaled StartApp has two buttons
called Stock and Cash.
Yoe can see the event handler for Stock and Cash below.
If I click on Stock button then form Stock is displayed and if I click on
Cash button
then Cash form is displayed. So far so good.

Now to my little problem if I for example click on Stock button four times
then four Stock
forms will be displayed.

So I don't want to be able to start several Stock forms or Cash forms how is
that done.
If I need to start the Cash form I will have to close the Stock form how is
done done.

private void BtnStock_Click(object sender, EventArgs e)
{
new Stock().Show();
}

private void BtnCash_Click(object sender, EventArgs e)
{
new Cash().Show();
}

//Tony

 

[Ignacio Machin ( .NET/ C# MVP )]

Hello!

My start form that is run from Program ccaled StartApp has two buttons
called Stock and Cash.
Yoe can see the event handler for Stock and Cash below.
If I click on Stock button then form Stock is displayed and if I click on
Cash button
then Cash form is displayed. So far so good.

Now to my little problem if I for example click on Stock button four times
then four Stock
forms will be displayed.

So I don't want to be able to start several Stock forms or Cash forms howis
that done.
If I need to start the Cash form I will have to close the Stock form how is
done done.

private void BtnStock_Click(object sender, EventArgs e)
{
       new Stock().Show();

}

private void BtnCash_Click(object sender, EventArgs e)
{
     new Cash().Show();

}

//Tony

Hi,

Instead of using Show() use ShowDialog()

 

[Pavel Minaev]

Hello!

My start form that is run from Program ccaled StartApp has two buttons
called Stock and Cash.
Yoe can see the event handler for Stock and Cash below.
If I click on Stock button then form Stock is displayed and if I click on
Cash button
then Cash form is displayed. So far so good.

Now to my little problem if I for example click on Stock button four times
then four Stock
forms will be displayed.

So I don't want to be able to start several Stock forms or Cash forms howis
that done.
If I need to start the Cash form I will have to close the Stock form how is
done done.

private void BtnStock_Click(object sender, EventArgs e)
{
       new Stock().Show();

}

private void BtnCash_Click(object sender, EventArgs e)
{
     new Cash().Show();

}

Store a reference to the form you open into a field. Check it for null
every time you open a new form - if it's not null, then there's a
previous form, and you Close() that before opening the new one.