TextBox validation after button click

[lpeder6]

Hello. I'm developing a complex UI with multiple classes and methods where one calls the next. Everything is working well with radio buttons and combo boxes as the user makes one choice and the code moves on to the next class/method. However, when it comes to text boxes, I have no way to validate an empty text box once the user presses the corresponding button because there's no way to go back to the text box and wait for the user to enter data. Here's the code for the label, text box, and button:

public void cmbSrchOpt_SelectedIndexChanged(object sender, EventArgs e)
{
    if (cmbSrchOpt.SelectedIndex == 0)
    {
        lblUniqueID.AutoSize = true;
        lblUniqueID.Text = "Enter Unique ID:";
        lblUniqueID.Location = new Point(45, 305);
        lblUniqueID.TabIndex = 6;
        lblUniqueID.Font = new Font("Arial", 12F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(0)));
        lblUniqueID.ForeColor = Color.FromArgb(((int)(((byte)(0)))), ((int)(((byte)(38)))), ((int)(((byte)(119)))));
        lblUniqueID.Name = "lblUniqueID";
        lblUniqueID.Size = new Size(431, 30);
        Controls.Add(lblUniqueID);
        //
        // txtUniqueID
        //
        txtUniqueID.Font = new Font("Arial", 12F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(0)));
        txtUniqueID.Location = new Point(190, 305);
        txtUniqueID.Name = "txtUniqueID";
        txtUniqueID.Size = new Size(213, 28);
        txtUniqueID.BorderStyle = BorderStyle.FixedSingle;
        txtUniqueID.TabIndex = 7;
            Controls.Add(txtUniqueID);
        txtUniqueID.Select();
            //
        // btnEnterUID
        //
        btnEnterUID.AutoSize = true;
        btnEnterUID.Font = new Font("Arial", 12F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(0)));
        btnEnterUID.Location = new Point(420, 305);
        btnEnterUID.Text = "Enter";
        btnEnterUID.BackColor = Color.FromArgb(((int)(((byte)(190)))), ((int)(((byte)(190)))), ((int)(((byte)(190)))));
        btnEnterUID.TabIndex = 8;
        btnEnterUID.Name = "btnEnterUID";
        btnEnterUID.Size = new Size(100, 28);
        Controls.Add(btnEnterUID);
        btnEnterUID.Click += new EventHandler(btnEnterUID_Clicked);
    }
}

Here is the code for the event handler:

public void btnEnterUID_Clicked(object sender, EventArgs e)
{
    Unique_ID = txtUniqueID.Text;
    
    /// <summary>
    /// The issue here is if Unique_ID is blank,
    /// there's no way for the program to go back
    /// to the previous location to allow the
    /// user another chance to enter data.
    /// </summary>

    // Remove the previous elements
    // and add label displaying data
    // user entered in text box.
    Controls.Remove(lblUniqueID);
    Controls.Remove(txtUniqueID);
    Controls.Remove(btnEnterUID);

    //
    // lblShowUID
    //
    lblShowUID.AutoSize = true;
    lblShowUID.Text = "Unique ID: " + Unique_ID;
    lblShowUID.Location = new Point(45, 305);
    lblShowUID.TabIndex = 3;
    lblShowUID.Font = new Font("Arial", 12F, FontStyle.Bold, GraphicsUnit.Point, ((byte)(0)));
    lblShowUID.ForeColor = Color.FromArgb(((int)(((byte)(0)))), ((int)(((byte)(38)))), ((int)(((byte)(119)))));
    lblShowUID.Name = "lblShowUID";
    lblShowUID.Size = new Size(431, 30);
    Controls.Add(lblShowUID);
    lblShowUID.BringToFront();
    ProcessDate();
}

I tried searching for something like this on one of the threads and came up with nothing. I found nothing during several Google searches. Hopefully someone understands what I'm trying to do and let me know if there's a possible solution.

 

[Skydiver]

There is the WinForms Validating event that lets you check before the focus is lost.

Control.Validating Event (System.Windows.Forms)

Occurs when the control is validating.

learn.microsoft.com

That is part of the WinForms validation subsystem. You can use part or all of it as you please.

User input validation - Windows Forms .NET

Learn about several ways that you can use Windows Forms to validate user input in your applications.

learn.microsoft.com

 

[Skydiver]

Also, a quick aside...

Your way of dynamically adding and removing controls from the UI is not the Windows way, and therefore not the WinForms way of doing things. It goes against the Windows UI design guidelines. What you are doing is more of the single page (web) application way of doing things. In general, the kind of UI you have where you have multiple steps of gathering input is better served by the Windows "Wizard" dialog styles.

Wizards - Win32 apps

Despite that wonderful, whimsical name, wizards are not really a special form of user interface, and they have only a particular range of utility.

learn.microsoft.com

 

[lpeder6]

Also, a quick aside...

Your way of dynamically adding and removing controls from the UI is not the Windows way, and therefore not the WinForms way of doing things. It goes against the Windows UI design guidelines. What you are doing is more of the single page (web) application way of doing things. In general, the kind of UI you have where you have multiple steps of gathering input is better served by the Windows "Wizard" dialog styles.

Wizards - Win32 apps

Despite that wonderful, whimsical name, wizards are not really a special form of user interface, and they have only a particular range of utility.

learn.microsoft.com

Thanks for the advice.

This option was given to the focus group, along with the UI I'm developing, and the users selected this option as they didn't like the look or feel of the wizard. I agree a wizard would be easier to develop. However, they're the ones who are going to be using it and they felt a Windows UI would feel more like an app and less like a system function.