用户控件的基本用法，关闭用户控件并打开另一个用户控件参数

Question

ladies and gentlemen, once again I unfortunately am going to bother you with newbie stuff. I have searched for this information for hours, so if there's a thread with what I want on it, it's buried deeper than I could find.

This was my first question here, and Mark Hall was kind enough to set me straight. Since then, I have created a new project and recreated my first three screens as user controls – a container/login, a choice screen, and a main screen (currently empty). If a user has more than one collection, the choice screen pops up and allows them to choose a collection.

I did run into a snag with parameters, but I'm solving that by overloading the form declaration (solution found here) – yes, I know it's much better to send parameters through calls, but I'd hate to have to create a call for each parameter (do I?) and… OK, OK, I'm better at this than {get, set}. Man, I hate being a newbie.

Anyways, I'm having trouble with the choice form – I can't seem to call it, close it, then go to the main form. I have no problem (if there's only one collection) in going straight to the main form, it's that darn choice form. Yes, I know I could include a choice datagridview, but a few of our end users aren't the sharpest bulb in the tool shed, and need hand-holding. Anyways, here's the code.

CONTAINER/LOGIN SCREEN

namespace DeleteThis
{
    public partial class ContainerForm : Form
    {
        Main Main = new Main();
        LoginCollectionChoice LoginChoice = new LoginCollectionChoice();
        DataTable dtPermissions = new DataTable();
        public ContainerForm()
        {
            InitializeComponent();
            Main.ExitEvent += new Main.ExitEventHandler(Main_ExitEvent);
            LoginChoice.ExitEvent += new
            LoginCollectionChoice.ExitEventHandler(LoginChoice_ExitEvent);
        }

        void LoginChoice_ExitEvent(object sender, EventArgs e)
        {
            pnlcontainer.Controls.Remove(LoginChoice);
        }

        void Main_ExitEvent(object sender, EventArgs e)
        {
            pnlcontainer.Controls.Remove(Main);
        }

    private void btnLogin_Click(object sender, EventArgs e)
    {
        LoginProcedure();
    }

    private void LoginProcedure()
    {
        DataTable dtPermissions = AdminClass.GetCollectionsForUser(int.Parse(txtbxUserName.Text));
        if (dtPermissions.Rows.Count == 1)
        {
            //Valid user, one collection.  Head right in.
            pnlcontainer.Controls.Add(Main);
            Main.BringToFront();
        }
        else
        {
            //More than one collection found.  Giving user choice
            LoginCollectionChoice LoginChoice = new LoginCollectionChoice(dtPermissions);

            pnlcontainer.Controls.Add(LoginChoice);
            LoginChoice.BringToFront();

        }
    }

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

}

I hope I didn't kill anything in the snipping. And now the choice screen…

public partial class LoginCollectionChoice : UserControl
{
    public delegate void ExitEventHandler(object sender, EventArgs e);
    public event ExitEventHandler ExitEvent;
    private static DataTable dtPermit;
    DataTable dtPermissions = new DataTable();

    public LoginCollectionChoice()
    {
    }

    public LoginCollectionChoice(DataTable dtPermissions)
    {
        InitializeComponent();
        GrdCollection.DataSource = dtPermissions;
        dtPermit = dtPermissions;
    }

    private void btnChoose_Click(object sender, EventArgs e)
    {
    //Code for the user to choose a collection
    ExitEvent(this, new EventArgs());
    }
}

I've snipped all non-relevent code, I hope you gentlemen and ladies can help this newbie get on the right path. Please, be gentle, you wouldn't want to see me cry, would you? :) Oh! And if you know of any great tutorial sites, please email them to me. I'd prefer to spend a week on tutorials than a week on stumbling and asking here. Thank you all very much.

Answer 1

Are you calling logonForm.Show()?

It seems like you'd need to show it that way.

You use BringToFront(), but I think it needs to be shown first.

Answer 2

The first thing that jumps out to me is that you are calling

LoginCollectionChoice LoginChoice = new LoginCollectionChoice(dtPermissions);

which is creating a local variable called LoginChoice, which is not the same as your class variable even though they share the same name.

What you want to do is to not declare a local variable in that method. Change that line to

LoginChoice = new LoginCollectionChoice(dtPermissions);

Having said that, I believe tylerjgarland in that you need to call .Show() first. And the way you are closing the form is certainly odd. I would create a form, showDialog, get the result and then close the form that way.