How do i...remove the item from combobox once it's been selected in the previous combobox

Question

0.00/5 (No votes)

See more:

I'm lost here, I wanna remove the item from ComboBox once it's been selected in the previous ComboBox. I have tried many approaches but didn't resolve this problem. Please help me in solving this problem and below I've included all of the code. Any tips would be greatly appreciated!

What I have tried:

C#

ComboBox[] combo_for_constraint = new ComboBox[count];
int combo_for_constraint_x = 250, combo_for_constraint_y = 50;
for (int i = 1; i < count; i++)
{
    combo_for_constraint[i] = new ComboBox();
    combo_for_constraint[i].Location = new System.Drawing.Point(combo_for_constraint_x,
combo_for_constraint_y + (i * 10));
    combo_for_constraint[i].Size = new Size(100, 50);
    combo_for_constraint[i].Name = "combo_for_constraintbx" + i.ToString();
    combo_for_constraint[i].DropDownStyle = ComboBoxStyle.DropDownList;
    tabPage2.Controls.Add(combo_for_constraint[i]);
    tabPage2.ResumeLayout(false);
    combo_for_constraint_y += 40;
    tabPage2.Refresh();
    if (i >= 2 && combo_for_constraint[i - 1].Text == "PRIMARY KEY")
    {
        combo_for_constraint[i + 1].Items.RemoveAt(1);
    }
    else
    {
        combo_for_constraint[i].Items.Add("UNIQUE");
        combo_for_constraint[i].Items.Add("PRIMARY KEY");
        combo_for_constraint[i].Items.Add("FOREIGN KEY");
    }
}

Posted 5-Jan-21 7:10am

Dev-Ahsan

Updated 6-Jan-21 19:16pm

Richard Deeming

v2

Add a Solution

Comments

CHill60 5-Jan-21 13:12pm

What happens when you run the code?
One tip I will give you is don't start at 1 and go to the end of the list - when you remove an item, all the subsequent items will have a different index. So start at the end and move towards the start

Dev-Ahsan 5-Jan-21 13:28pm

when I run the code all the ComboBox remains the same but I won't if I select "Primary Key" from the comboBox the item Primary will be removed from the ComboBox except the ComboBox in which I select. I've tried but not work

Richard MacCutchan 6-Jan-21 10:35am

I have tried various values for count but I only ever get one ComboBox created and the program then aborts.

Richard MacCutchan 6-Jan-21 10:49am

I have tried a number of other tests and can still not get a working sample. I think part of the problem is the way you are trying to update one of the combo boxes in the creation phase.

You should first create the combo boxes and populate them with the required data. The code to delete an item from a box should be put into an event handler that is triggered when the selection changes.

Dev-Ahsan 7-Jan-21 1:02am

Got it, Thanks for your advice it's really helped me!

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard MacCutchan · Accepted Answer · 2021-01-06T05:31:00

Here is some code that works, although it is not an ideal implementation. But it does at least show how the SelectedIndexChanged event should be handled.

C#

ComboBox[] combo_for_constraint;
void SetupCombos()
{
    int count = 3;
    combo_for_constraint = new ComboBox[count];
    int combo_for_constraint_x = 250, combo_for_constraint_y = 50;
    for (int i = 1; i < count; i++)
    {
        combo_for_constraint[i] = new ComboBox();
        combo_for_constraint[i].Location = new System.Drawing.Point(combo_for_constraint_x,
            combo_for_constraint_y + (i * 10));
        combo_for_constraint[i].Size = new Size(100, 50);
        combo_for_constraint[i].Name = "combo_for_constraintbx" + i.ToString();
        combo_for_constraint[i].DropDownStyle = ComboBoxStyle.DropDownList;
        this.Controls.Add(combo_for_constraint[i]);
        this.ResumeLayout(false);
        combo_for_constraint_y += 40;
        this.Refresh();
        combo_for_constraint[i].Items.Add("UNIQUE");
        combo_for_constraint[i].Items.Add("PRIMARY KEY");
        combo_for_constraint[i].Items.Add("FOREIGN KEY");
        combo_for_constraint[i].SelectedIndex = 0;
    }
    combo_for_constraint[1].SelectedIndexChanged += new System.EventHandler(Combo1_SelectedIndexChanged);
}

void Combo1_SelectedIndexChanged(object sender, System.EventArgs e)
{
    ComboBox comboBox = (ComboBox)sender;
    if (comboBox == combo_for_constraint[1] && combo_for_constraint[1].Text == "PRIMARY KEY")
    {
        combo_for_constraint[2].Items.RemoveAt(1);
        combo_for_constraint[2].DroppedDown = true;
    }
}

Dev-Ahsan · Accepted Answer · 2021-01-06T19:16:00

Finally solved by the help of

@Richard-MacCutchanWatch

C#

void ComboBuild()
        {
            combo_for_constraint = new ComboBox[count];
            int combo_for_constraint_x = 250, combo_for_constraint_y = 50;
            for (int i = 0; i < count; i++)
            {
                combo_for_constraint[i] = new ComboBox();
                combo_for_constraint[i].Location = new System.Drawing.Point(combo_for_constraint_x,
                    combo_for_constraint_y + (i * 10));
                combo_for_constraint[i].Size = new Size(100, 50);
                combo_for_constraint[i].Name = "combo_for_constraintbx" + i.ToString();
                combo_for_constraint[i].DropDownStyle = ComboBoxStyle.DropDownList;
                tabPage2.Controls.Add(combo_for_constraint[i]);
                tabPage2.ResumeLayout(false);
                combo_for_constraint_y += 40;
                tabPage2.Refresh();
                combo_for_constraint[i].Items.Add("UNIQUE");
                combo_for_constraint[i].Items.Add("PRIMARY KEY");
                combo_for_constraint[i].Items.Add("FOREIGN KEY");
                //combo_for_constraint[i].SelectedIndex = 0;
                combo_for_constraint[i].SelectedIndexChanged += new System.EventHandler(Combo1_SelectedIndexChanged);
            }
        }


        private void Combo1_SelectedIndexChanged(object sender, EventArgs e)
        {
            ComboBox comboBox = (ComboBox)sender;
            for (int i = 0; i < int.Parse(textBox3.Text); i++)
            {
                if (comboBox == combo_for_constraint[i] && combo_for_constraint[i].Text == "PRIMARY KEY")
                {
                    for (int j = 0; j < int.Parse(textBox3.Text); j++)
                    {
                        if (combo_for_constraint[j].Text == "PRIMARY KEY")
                        {
                            continue;
                        }
                        else
                            combo_for_constraint[j].Items.Remove("PRIMARY KEY");
                    }
                }
            }
        }

How do i...remove the item from combobox once it's been selected in the previous combobox

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0