Cant figure out why getConnectionString keeps passing NULL
-1
Im trying to get my connection string from one form to another but it keeps passing NULL Im new to working with different classes so it could be a verry simple mistake.
Form 1
public partial class Form1 : Form
{
private string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
public Form1()
{
InitializeComponent();
}
public string getConnectionString()
{
return ConnectionString;
}
private void btn_login_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("Select count(*) From tblLogin where Username ='" + txt_username.Text + "' and Password ='" + txt_password.Text + "'", con);
DataTable dt = new DataTable();
sqa.Fill(dt);
if (dt.Rows[0][0].ToString() == "1")
{
this.Hide();
Form2 main = new Form2();
main.Show();
}
else
{
MessageBox.Show("Username or Password is incorrect");
txt_username.Clear();
txt_password.Clear();
}
}
}
Form 2
public partial class Form2 : Form
{
private Form1 form1;
public Form2()
{
InitializeComponent();
}
private void btn_search_Click(object sender, EventArgs e)
{
if (rb_Artist.Checked == true)
{
String ConnectionString = form1.getConnectionString();
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("SELECT * FROM tblArtist where Name like" + txt_search.Text, con);
DataTable dt = new DataTable();
sqa.Fill(dt);
dataGridView1.DataSource = dt;
}
}
}
c# database forms class
edited Nov 15 '18 at 12:06
er-sho
6,5452618
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
add a comment |
-1
Im trying to get my connection string from one form to another but it keeps passing NULL Im new to working with different classes so it could be a verry simple mistake.
Form 1
public partial class Form1 : Form
{
private string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
public Form1()
{
InitializeComponent();
}
public string getConnectionString()
{
return ConnectionString;
}
private void btn_login_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("Select count(*) From tblLogin where Username ='" + txt_username.Text + "' and Password ='" + txt_password.Text + "'", con);
DataTable dt = new DataTable();
sqa.Fill(dt);
if (dt.Rows[0][0].ToString() == "1")
{
this.Hide();
Form2 main = new Form2();
main.Show();
}
else
{
MessageBox.Show("Username or Password is incorrect");
txt_username.Clear();
txt_password.Clear();
}
}
}
Form 2
public partial class Form2 : Form
{
private Form1 form1;
public Form2()
{
InitializeComponent();
}
private void btn_search_Click(object sender, EventArgs e)
{
if (rb_Artist.Checked == true)
{
String ConnectionString = form1.getConnectionString();
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("SELECT * FROM tblArtist where Name like" + txt_search.Text, con);
DataTable dt = new DataTable();
sqa.Fill(dt);
dataGridView1.DataSource = dt;
}
}
}
c# database forms class
edited Nov 15 '18 at 12:06
er-sho
6,5452618
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
What specifically isnull?
– mjwills
Nov 15 '18 at 12:04
Changeprivate stringtoprivate const string.
– mjwills
Nov 15 '18 at 12:05
1
Possible duplicate of What is a NullReferenceException, and how do I fix it?
– mjwills
Nov 15 '18 at 12:08
add a comment |
-1
-1
-1
Im trying to get my connection string from one form to another but it keeps passing NULL Im new to working with different classes so it could be a verry simple mistake.
Form 1
public partial class Form1 : Form
{
private string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
public Form1()
{
InitializeComponent();
}
public string getConnectionString()
{
return ConnectionString;
}
private void btn_login_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("Select count(*) From tblLogin where Username ='" + txt_username.Text + "' and Password ='" + txt_password.Text + "'", con);
DataTable dt = new DataTable();
sqa.Fill(dt);
if (dt.Rows[0][0].ToString() == "1")
{
this.Hide();
Form2 main = new Form2();
main.Show();
}
else
{
MessageBox.Show("Username or Password is incorrect");
txt_username.Clear();
txt_password.Clear();
}
}
}
Form 2
public partial class Form2 : Form
{
private Form1 form1;
public Form2()
{
InitializeComponent();
}
private void btn_search_Click(object sender, EventArgs e)
{
if (rb_Artist.Checked == true)
{
String ConnectionString = form1.getConnectionString();
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("SELECT * FROM tblArtist where Name like" + txt_search.Text, con);
DataTable dt = new DataTable();
sqa.Fill(dt);
dataGridView1.DataSource = dt;
}
}
}
c# database forms class
edited Nov 15 '18 at 12:06
er-sho
6,5452618
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
Im trying to get my connection string from one form to another but it keeps passing NULL Im new to working with different classes so it could be a verry simple mistake.
Form 1
public partial class Form1 : Form
{
private string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
public Form1()
{
InitializeComponent();
}
public string getConnectionString()
{
return ConnectionString;
}
private void btn_login_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("Select count(*) From tblLogin where Username ='" + txt_username.Text + "' and Password ='" + txt_password.Text + "'", con);
DataTable dt = new DataTable();
sqa.Fill(dt);
if (dt.Rows[0][0].ToString() == "1")
{
this.Hide();
Form2 main = new Form2();
main.Show();
}
else
{
MessageBox.Show("Username or Password is incorrect");
txt_username.Clear();
txt_password.Clear();
}
}
}
Form 2
public partial class Form2 : Form
{
private Form1 form1;
public Form2()
{
InitializeComponent();
}
private void btn_search_Click(object sender, EventArgs e)
{
if (rb_Artist.Checked == true)
{
String ConnectionString = form1.getConnectionString();
SqlConnection con = new SqlConnection(ConnectionString);
SqlDataAdapter sqa = new SqlDataAdapter("SELECT * FROM tblArtist where Name like" + txt_search.Text, con);
DataTable dt = new DataTable();
sqa.Fill(dt);
dataGridView1.DataSource = dt;
}
}
}
c# database forms class
c# database forms class
edited Nov 15 '18 at 12:06
er-sho
6,5452618
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
edited Nov 15 '18 at 12:06
er-sho
6,5452618
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
edited Nov 15 '18 at 12:06
er-sho
6,5452618
edited Nov 15 '18 at 12:06
er-sho
6,5452618
edited Nov 15 '18 at 12:06
er-sho
6,5452618
6,5452618
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
asked Nov 15 '18 at 11:59
im_ Rubenim_ Ruben
188
188
What specifically isnull?
– mjwills
Nov 15 '18 at 12:04
Changeprivate stringtoprivate const string.
– mjwills
Nov 15 '18 at 12:05
1
Possible duplicate of What is a NullReferenceException, and how do I fix it?
– mjwills
Nov 15 '18 at 12:08
add a comment |
What specifically isnull?
– mjwills
Nov 15 '18 at 12:04
Changeprivate stringtoprivate const string.
– mjwills
Nov 15 '18 at 12:05
1
Possible duplicate of What is a NullReferenceException, and how do I fix it?
– mjwills
Nov 15 '18 at 12:08
What specifically is
null?– mjwills
Nov 15 '18 at 12:04
What specifically is
null?– mjwills
Nov 15 '18 at 12:04
Change
private string to private const string.– mjwills
Nov 15 '18 at 12:05
Change
private string to private const string.– mjwills
Nov 15 '18 at 12:05
1
1
Possible duplicate of What is a NullReferenceException, and how do I fix it?
– mjwills
Nov 15 '18 at 12:08
Possible duplicate of What is a NullReferenceException, and how do I fix it?
– mjwills
Nov 15 '18 at 12:08
add a comment |
2 Answers
2
active
oldest
votes
3
It's because you never actually initialize Form1 in your Form2.
Change private Form1 form1; to private Form1 form1 = new Form1();
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
2
Thanks alot I didnt even realise it after trying for over an hour!
– im_ Ruben
Nov 15 '18 at 12:11
No problem also just a tip if you want to use variables like connection strings in several forms or classes configure them in the app.config file. You can access and change them more easy than trying to pass them from form to form. .
– Niklas7
Nov 15 '18 at 12:24
add a comment |
-1
public static string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
using in Form2
not create form1 object
String ConnectionString = form1.ConnectionString
this variable try to solve this problem
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
3
It's because you never actually initialize Form1 in your Form2.
Change private Form1 form1; to private Form1 form1 = new Form1();
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
2
Thanks alot I didnt even realise it after trying for over an hour!
– im_ Ruben
Nov 15 '18 at 12:11
No problem also just a tip if you want to use variables like connection strings in several forms or classes configure them in the app.config file. You can access and change them more easy than trying to pass them from form to form. .
– Niklas7
Nov 15 '18 at 12:24
add a comment |
3
It's because you never actually initialize Form1 in your Form2.
Change private Form1 form1; to private Form1 form1 = new Form1();
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
2
Thanks alot I didnt even realise it after trying for over an hour!
– im_ Ruben
Nov 15 '18 at 12:11
No problem also just a tip if you want to use variables like connection strings in several forms or classes configure them in the app.config file. You can access and change them more easy than trying to pass them from form to form. .
– Niklas7
Nov 15 '18 at 12:24
add a comment |
3
3
3
It's because you never actually initialize Form1 in your Form2.
Change private Form1 form1; to private Form1 form1 = new Form1();
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
It's because you never actually initialize Form1 in your Form2.
Change private Form1 form1; to private Form1 form1 = new Form1();
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
answered Nov 15 '18 at 12:06
Niklas7Niklas7
1262
1262
2
Thanks alot I didnt even realise it after trying for over an hour!
– im_ Ruben
Nov 15 '18 at 12:11
No problem also just a tip if you want to use variables like connection strings in several forms or classes configure them in the app.config file. You can access and change them more easy than trying to pass them from form to form. .
– Niklas7
Nov 15 '18 at 12:24
add a comment |
2
Thanks alot I didnt even realise it after trying for over an hour!
– im_ Ruben
Nov 15 '18 at 12:11
No problem also just a tip if you want to use variables like connection strings in several forms or classes configure them in the app.config file. You can access and change them more easy than trying to pass them from form to form. .
– Niklas7
Nov 15 '18 at 12:24
2
2
Thanks alot I didnt even realise it after trying for over an hour!
– im_ Ruben
Nov 15 '18 at 12:11
Thanks alot I didnt even realise it after trying for over an hour!
– im_ Ruben
Nov 15 '18 at 12:11
No problem also just a tip if you want to use variables like connection strings in several forms or classes configure them in the app.config file. You can access and change them more easy than trying to pass them from form to form. .
– Niklas7
Nov 15 '18 at 12:24
No problem also just a tip if you want to use variables like connection strings in several forms or classes configure them in the app.config file. You can access and change them more easy than trying to pass them from form to form. .
– Niklas7
Nov 15 '18 at 12:24
add a comment |
-1
public static string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
using in Form2
not create form1 object
String ConnectionString = form1.ConnectionString
this variable try to solve this problem
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
add a comment |
-1
public static string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
using in Form2
not create form1 object
String ConnectionString = form1.ConnectionString
this variable try to solve this problem
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
add a comment |
-1
-1
-1
public static string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
using in Form2
not create form1 object
String ConnectionString = form1.ConnectionString
this variable try to solve this problem
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
public static string ConnectionString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersRubenDocumentsdbPlatenCompany.mdf;Integrated Security = True; Connect Timeout = 30";
using in Form2
not create form1 object
String ConnectionString = form1.ConnectionString
this variable try to solve this problem
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
answered Nov 15 '18 at 12:22
mitulpatelmitulpatel
11
11
add a comment |
add a comment |
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What specifically is
null?– mjwills
Nov 15 '18 at 12:04
Change
private stringtoprivate const string.– mjwills
Nov 15 '18 at 12:05
1
Possible duplicate of What is a NullReferenceException, and how do I fix it?
– mjwills
Nov 15 '18 at 12:08