how to get ID on an item in combo box

Question

1.00/5 (1 vote)

See more:

hello, i wanted to get ID of an selected item in combo box in c#.
i tried the following code and getting the value of selected item, but haven't any idea to get ID from database.

C#

int ProductIndex = ProductsComboBox.SelectedIndex;
      string productName = ProductsComboBox.Items[ProductIndex].ToString();

Posted 29-Jul-12 1:38am

SR.Rizwan

Updated 2-Feb-23 10:42am

Add a Solution

5 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)

OriginalGriff · Answer 1 · 2012-07-29T02:12:00

I assume that whatever class your ProductsComboBox contains has overridden ToString, to give you the human readable value. If so, then just cast the object to your class:

C#

int ProductIndex = ProductsComboBox.SelectedIndex;
MyClass selected = ProductsComboBox.Items[ProductIndex] as MyClass;
if (selected != null)
   {
   string productName = selected.ProductName;
   ...
   }

Or better:

C#

MyClass selected = ProductsComboBox.SelectedItem as MyClass;
if (selected != null)
   {
   string productName = selected.ProductName;
   ...
   }

Presumably, your class contains the ID already!

Santhosh Kumar Jayaraman · Answer 2 · 2012-07-29T02:14:00

Solution 2

When binding to combobox use display member property to display name and valuemember property to Id.

C#

CmbProduct.DataSource=datatable1;
CmbProduct.DisplayMember="ProductName";
CmbProduct.ValueMember="ProductId;
CmbProduct.DataBind();

Then in combobox selected index changed,

C#

int ProductIndex = ProductsComboBox.SelectedIndex;//this will give index
string productName = ProductsComboBox.Text.ToString()//this will give DIsplay name;
int ProductId=ProductsComboBox.SelectedValue.ToString();//this will give product Id

Posted 29-Jul-12 2:14am

Santhosh Kumar Jayaraman

Comments

SR.Rizwan 29-Jul-12 8:33am

it is giving me the error "Object reference not set to an instance of an object."
string productName = ProductsComboBox.Text.ToString(); This line works fine, it contains the value of productName.
what i am doing wrong?

Santhosh Kumar Jayaraman 29-Jul-12 9:16am

Make sure you fetch both product name and productid from database and store it in your datatable. Then make sure you set value member of combobox to productid.

SR.Rizwan 29-Jul-12 11:21am

yes i am fetching the whole row. below is my code. can't figure it out where is the problem.

private void ProductForm_Shown(object sender, EventArgs e)
{
SqlCeConnection Connection = new SqlCeConnection(ConString);
Connection.Open();
SqlCeDataAdapter da = new SqlCeDataAdapter("Select * from CastingMaterial", Connection);
DataTable dt = new DataTable();
da.Fill(dt);
for (int i = 0; i < dt.Rows.Count; i++)
{
ProductsComboBox.Items.Add(dt.Rows[i]["PartName"]);

}
ProductsComboBox.DisplayMember = "PartName";
ProductsComboBox.ValueMember = "PartId";
Connection.Close();
}

private void ProductsComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
int ProductIndex = ProductsComboBox.SelectedIndex;
string productName = ProductsComboBox.Text.ToString();
int ProductId =Convert.ToInt32(ProductsComboBox.SelectedValue);
SqlCeConnection Connection = new SqlCeConnection(ConString);
Connection.Open();
String Query = "SELECT * From CastingMaterial where PartId=@PartId";
SqlCeDataAdapter da = new SqlCeDataAdapter(Query, Connection);
da.SelectCommand.Parameters.AddWithValue("PartId", ProductId);
DataSet ds = new DataSet();
SqlCeCommandBuilder commandBuilder = new SqlCeCommandBuilder(da);

BindingSource bsource = new BindingSource();

da.Fill(ds, "CastingMaterial");
bsource.DataSource = ds.Tables["CastingMaterial"];
Productgv.DataSource = bsource;
Connection.Close();
}

Member 15912660 · Answer 3 · 2023-02-02T10:42:00

Solution 5

You can pull the selected item out as a "ComboboxItem" and retrieve the "Value" from there:
Int64.Parse((ProductsComboBox.SelectedItem as ComboboxItem).Value.ToString());

Posted 2-Feb-23 10:42am

Member 15912660

Pooya F.A · Answer 4 · 2012-07-29T02:20:00

create a table in sqlServer with two columns. Save your Table as myTable. One column for Product and name it PRODUCT as char. And the other column for storing ProductID named ID as char. And use below code to read from database.

C#

SqlConnection con=new SqlConnection("Connection string");

SqlCommand cmd=new SqlCommand("SELECT ID FROM myTable WHERE PRODUCT='" + ProductsComboBox.Items[ProductIndex].ToString()+"'");

if (con.State == ConnectionState.Closed)
     con.Open();

SqlDataReader rdr = cmd.ExecuteReader();          
while (rdr.Read())
{
     string strID=(string)rdr["ID"];
}

then strID will be the ID of your product.

Member 15396067 · Answer 5 · 2021-10-15T20:00:00

C#

  object comboValue;
  private void comboFill()
  {
      DataTable dt = DataBase.GetData("Select CategoryName, Id from Category");
      combxgrup.DataSource = dt;
      combxgrup.DisplayMember = "CategoryName";
      combxgrup.ValueMember = "Id";
      comboValue = combxgrup.SelectedValue;
  }

********************************************************************************
 MessageBox.Show(comboValue);

how to get ID on an item in combo box

5 solutions

Solution 1

Solution 2

Solution 5

Solution 3

Solution 4

Add your solution here

Preview 0