An object reference is required for the nonstatic field, method, or property

I know you have all seen this one before, for which i am sorry. But I can't figure this out.

I am not sure if what I am trying to do here will even work in the end but this is my first project and I am learning as I go, so please try not to laugh.

I have a combobox of form1 that is bound to a data source and on form3 I have a report viewer that (I hope) will load using the text that is in the combobox on form1.

This is where I have the problem! I have searched many forums but still don’t really understand!!

(it is the WHERE SaveName = '" + Form1.comboBox2.Text + "'";where the error occurs, as follows:

(An object reference is required for the nonstatic field, method, or property 'Stock_Scan.Form1.comboBox2')

Here is the code from form 3.

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace Stock_Scan

{

public partial class Form3 : Form

{

public Form3()

{

InitializeComponent();

}

private void reportViewer1_Load(object sender, EventArgs e)

{

SqlConnection conn = new System.Data.SqlClient.SqlConnection("Initial Catalog=StockScan;Data Source=(local);Integrated Security=SSPI");

String ls_sqlstate = "SELECT * FROM ProductHis WHERE SaveName = '" + Form1.comboBox2.Text + "'";

conn.Open();

SqlCommand cmd = new System.Data.SqlClient.SqlCommand(ls_sqlstate, conn);

cmd.ExecuteNonQuery();

conn.Close();

}

}

Any help would be greatly appriciated.

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An object reference is required for the nonstatic field, method, or property

atirado
Form1 is the class name, so not an instance of the form

the thing you shoud do is:

Form 3:

private String myParam;

public Form3(String yourParam)

{

InitializeComponent();

myParam = yourParam

}

so it becomes

String ls_sqlstate = "SELECT * FROM ProductHis WHERE SaveName = '" + myParam+ "'";

However, you shouldn't be doing this in the gui code!
The.B
Hi, Smegg

Additionally, I suggest you to use cmd.Parameter instead of directly adding string as param. That is to say use:
String ls_sqlstate = "SELECT * FROM ProductHis WHERE SaveName = @param";
cmd.Parameters.AddWithValue("param",value);

instead

It is more secure, since it will check the param input.
museicon

You could also try keeping a public string variable!

Set the string variable when the user chooses an item from the combobox!

Use this variable in form 3
Callan
Thank you for responding. But i am affriad i am not sure how to declare the combobox as static public. I know that sounds stupid but i am learning as i go along and i am still not sure how or why somethings work, I just keep trying different things until they do!
Ragnvald
Thank you all for your help think i may have this one now, but you can expect to see my name on this forum a few more times in the future!

Thanks again
Mark Goldstein
Thank you.

Lessons are long and hard when you dont know anything to begin with!!
mameelas
or you can declare your combobox as static public Form1 and then you can access it using Form1.comobox
Sniper167

good luck
shax
Ok thanks for your help that seem to have got over that little problem. But would you mind explaining, if i shouldn't be doing this in the gui code, what should i be doing
Paul Sanders

You open Form1.designer.cs, in this file you find the declarations and initialisations for all components and controls you create in form1 designer.

and in this file u edit the declaration of your combobox to static public, and in this way you can call this control anywhere in the project without creating an instance of form1.
An object reference is required for the nonstatic field, method, or property

Answer this question