CODEWITHSUNDEEP
c#.netwinforms
user1108948
user1108948

Reputation:

Switch among windows forms

I have a bunch of windows forms. Each form has "Back" and "Next" buttons for switching forms. For example, clicking "Back" on Form3 then we go to Form2. Then clicking "Next" button on Form2 then Form3 is shown.

Now my question is that if we click "Next" from the very beginning, it works smoothly. However if I click "Back" on Form3 then Form2 is displayed, then click "Next" on Form3 go to Form3. The code doesn't goto Form3_Load event. What is wrong in my code?

 public partial class Form3 : Form
{
    Form2 FormPrev;
    Form4 FormNext;
    List<DataRow> drlist = new List<DataRow>();
    DataTable dt = new DataTable();

    public Form3(Form2 _FormPrev)
    {
        InitializeComponent();
        this.FormPrev = _FormPrev;
    }

    private void btnCancel_Click(object sender, EventArgs e)
    {
        this.Close();
    }

    private void btnNext_Click(object sender, EventArgs e)
    {
        ShowNext();
    }

    private void btnBack_Click(object sender, EventArgs e)
    {
        ShowPrev();
    }

    private void ShowNext()
    {
        if (FormNext == null)
            FormNext = new Form4(this);
        FormNext.Show();
        this.Hide();
    }

    private void ShowPrev()
    {
        FormPrev.Show();
        this.Hide();
    }

    private void Form3_Load(object sender, EventArgs e)
    {
       // blah blah.
    }

Thanks.

Upvotes: 1

Views: 2821

Answers (3)

igofed
igofed

Reputation: 1442

That's a normal behaviour. Load is for load form, not for show. In your case you try to show hided form. If you want to use 

form.Show()

than use not a 

form.Hide()

but 

form.Close()

UPD: Code should be: 

public partial class Form3 : Form
{
    List<DataRow> drlist = new List<DataRow>();
    DataTable dt = new DataTable();

    public Form3()
    {
        InitializeComponent();
    }

    private void btnCancel_Click(object sender, EventArgs e)
    {
        this.Close();
    }

    private void btnNext_Click(object sender, EventArgs e)
    {
        ShowNext();
    }

    private void btnBack_Click(object sender, EventArgs e)
    {
        ShowPrev();
    }

    private void ShowNext()
    {
        Form4 formNext = new Form4();
        formNext.Show();
        this.Close();
    }

    private void ShowPrev()
    {
        Form2 formPrev = new Form2();
        formPrev.Show();
        this.Close();
    }

    private void Form3_Load(object sender, EventArgs e)
    {
       // blah blah.
    }
}

But there is a problem with such colutions - you shouldn't close your main form.

Upvotes: 0

Kev
Kev

Reputation: 1892

A form's Load event is only fired when the form is invoked for the first time. If you subsequently hide the form and reshow it then this is not reloading the form so the form's Load event is not fired.

If you want to use an event to handle when the form is re-displayed then you should look at the following more suitable events:

Activated Shown VisibleChanged

Upvotes: 3

Ike Starnes
Ike Starnes

Reputation: 68

Form Load event only gets fired before the form is shown for the first time. You should use a different event, like maybe Form Activated or GotFocus.

Upvotes: 1

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