How to Connect 2 forms in C# windows applications

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Hi,

I am creating a C# Windows forms application where there are 2 forms Form1 and Form2. I need to connect these 2 forms in a way that when one form is active other should be disabled. For eg, Form1 has a button on the click event of which form 2 is opened in the way

C#

Form2 newForm= new Form2();
newForm.Show();
this.Hide();

Now I want the functionality that when the Form2 is activated,then the Form1 which is open should be deactivated or Disabled, and it should be activated again when the form Form2 is closed .Can anybody help me out on solving this issue.Thanks in Advance.

Thanks
Jashobanta Chakraborty

Posted 9-Jan-12 3:07am

Jashobanta

Updated 3-Jun-18 20:35pm

lukeer

v2

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Comments

incaunu 9-Jan-12 9:18am

try newForm.ShowDialog(this);

4 solutions

Solution 3

You can do that on this way:
(I'm not sure for the quality, but it works for me)

C#

private void button1_Click(object sender, EventArgs e)
{
    Form2 newForm = new Form2(this);
    newForm.Show();
    this.Hide();
}

//In Form2
Form parentForm;
public Form2(Form form)
{
    InitializeComponent();

    this.parentForm = form;
}

// and on closing event
private void Form2_FormClosing(object sender, EventArgs e)
{
    this.parentForm.Visible = true;
}

Posted 9-Jan-12 3:33am

Drazen Pupovac

Updated 9-Jan-12 10:50am

v3

Comments

OriginalGriff 9-Jan-12 14:15pm

My only criticism of this is that it makes Form2 aware of Form1 - and Form1 is already aware of Form2. This reduces the scope for form reuse, and fixed what happens to an object outside Form2s domain.
This would be a bit better if the Form1 instance was passed through to the Form2 constructor as a generic Form object rather than the derived Form1, but it is still better in OOP terms to let Form1 handle itself, and Form2 remain in ignorance of it's existence. (Oh, and BTW m_variablenames are not the normal style for C#, it is recommended to use camelCase instead.)
Form1 m_form;
public Form2(Form1 form)
becomes
Form parentForm;
public Form2(Form form)

Drazen Pupovac 9-Jan-12 17:04pm

I agree, thanks for the advice. I improved my solution now (How much is it possible :)).

One question: I read that for private fields have naming convention like _variable. It's that ok?

OriginalGriff 10-Jan-12 3:22am

Not normally, no. In C# a leading underscore would normally indicate that this is teh private backing variable for a public method of a similar name:
private _myString;
public MyString
{
get {return _myString;}
set {_myString = value;}
}
But not everybody uses them, some would call the private field "myString" (I follow this myself)

Have a look at MSDN: http://msdn.microsoft.com/en-us/library/ms229045.aspx
The links on the left are pretty detailed.

Drazen Pupovac 10-Jan-12 5:32am

Thanks

Solution 2

Link the two forms (Form1 knows about Form2 and Forms2 knows about Form1).
Then use Form.Activate, Form.Deactivate, Form.Closed events on both

Posted 9-Jan-12 3:21am

Catalin Serafimescu

Solution 5

There is also a new solution by just changing the receiver form's Constructor with some parameter and based on this parameter you can read the data.

For example

C#

.......
string param;
public ReceiverFormName(string param)
{
this.param=param;
}
.......

And Call it As

C#

........
ReceiverFormName rec = new ReceiverFromName("Hello World");
........

I have Tested this for me! SGSM_Awesh

Posted 21-Aug-15 22:13pm

Awesh Vishwakarma

Updated 21-Aug-15 22:14pm

v2

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OriginalGriff · Accepted Answer · 2012-01-09T03:19:00

Solution 1

Do it the other way around, and use ShowDialog instead;

C#

Form2 newform = new Form2();
this.Hide();
newForm.ShowDialog();
this.Show();

ShowDialog will not return until newform is closed.

Posted 9-Jan-12 3:19am

OriginalGriff

Comments

Jashobanta 10-Jan-12 13:35pm

Thanks @OriginalGriff..It worked..

OriginalGriff 10-Jan-12 13:59pm

You're welcome!