Cannot implicitly convert type 'object' to 'string'. An explicit conversion exists (are you missing a cast?)

Question

I have to display values into text box while selecting drop down list. I have use data set to get values from db. The code is given below. Give me a proper solution. Thank you.

Code:

 protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
     {
        DataSet1TableAdapters.TextBoxTableTableAdapter tx;
        tx = new DataSet1TableAdapters.TextBoxTableTableAdapter();
        DataTable dt = new DataTable();
        dt = tx.GetstudData(int.Parse(DropDownList1.SelectedValue));
        foreach (DataRow row in dt.Rows)
           {
           TextBox1.Text = (row["FirstName"]); // error shown here
           TextBox2.Text = (row["SecondName"]); // error shown here
           }
     }

The dt contains First Name and Last Name values. While selecting student ID the appropriate value shoud be shown in text box1 and textbox 2.

Sql query:

SELECT FirstName, SecondName FROM TextBoxTable WHERE (Id = @Id)

Source:

<div>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True">
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
</div>

Data base:

enter image description here

What is the problem with setting of an appropriate [TextBox.Text](http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.textbox.text(v=vs.110).aspx) property from a [cell.value of the first row in datatable](http://stackoverflow.com/questions/13816490/get-cell-value-from-a-datatable-in-c-sharp)? — Eugene Podskal, Oct 16 '14 at 09:44
if datatable has rows, then TextBox1.Text=dt.Rows[0]["FirstName"]. — pradeep varma, Oct 16 '14 at 09:46
@pradeepvarma : If data table doesn't have rows, then what will be the code? — Vipin, Oct 16 '14 at 10:10

adityaswami89 · Answer 1 · 2014-10-16T10:15:07.363

3

You may want to do :

foreach (DataRow row in dt.Rows)
{

 TextBox1.Text = (row["FirstName"]);
 TextBox2.Text = (row["SecondName"]);
}

edited Oct 16 '14 at 10:15

answered Oct 16 '14 at 09:46

adityaswami89

573
6
15

can you please apply the above solution in my code. I have pasted your solution in my code, but it is generating one error. That istext box 1 and 2 is not exist in the current context – Vipin Oct 16 '14 at 10:07
Please try now with the above solution. I have updated the code . – adityaswami89 Oct 16 '14 at 10:15
Where you have updated the solution.! I couldn't find out? Please let me know. – Vipin Oct 16 '14 at 10:18
i have changed the Textbox1 to TextBox1. Please copy the above code as is and paste in your solution. It should work !!! – adityaswami89 Oct 16 '14 at 10:19
Please mark this as answered and open another question for this . :) – adityaswami89 Oct 16 '14 at 10:27

Pedro Costa · Accepted Answer · 2014-10-16T10:30:52.527

Change your code to:

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
     {
        DataSet1TableAdapters.TextBoxTableTableAdapter tx;
        tx = new DataSet1TableAdapters.TextBoxTableTableAdapter();
        DataTable dt = new DataTable();
        dt = tx.GetstudData(int.Parse(DropDownList1.SelectedValue));
        foreach (DataRow row in dt.Rows)
           {
           TextBox1.Text = (row["FirstName"].ToString());
           TextBox2.Text = (row["SecondName"].ToString());
           }
     }

The names of the text boxes are different from the ones you have in the asp file. C# is a case sensitive language.

EDIT: You have to convert it. A simple .ToString() should do it. Try not to change the complete subject of the topic also. You should have open a new question...because this breaks all the correct answers.

pradeep varma · Answer 3 · 2014-10-16T12:35:35.173

studentId is unique. DownDropList Contains Studentid. one student has one Name

if(DropDownList1.SelectedValue !="" && dt.Rows.Count()>0)
   {
       txtFirstname.Text= String.IsNullOrWhiteSpace(dt.Rows[0]["FirstName"]) ? "" : dt.Rows[0]["FirstName"];
     txtlastName.Text= String.IsNullOrWhiteSpace(dt.Rows[0]["LastName"]) ? "" : dt.Rows[0]["LastName"];      
}
 else
 {
   TextBox1.Text="";
  TextBox2.Text="";
 }

Cannot implicitly convert type 'object' to 'string'. An explicit conversion exists (are you missing a cast?)

3 Answers3