.NET (Core and Framework)

22-Jan-09 23:08

is it possible to stop the flow of the project?

i get error and it is catched in try catch block...

after that i don't want to continue...

i want transfer the flow to my starting page...

how can i do this...

Wendelius22-Jan-09 23:17

22-Jan-09 23:17

If it's a method you add for example return the the end of the catch block if there are statements outside the try-chatch structure. However, finally portion will still be executed. Then on the calling side you must handle this situation so that you don't continue there and so on.

The need to optimize rises from a bad design.My articles[^]

kulandaivel_mca200722-Jan-09 23:23

22-Jan-09 23:23

actually it is a connection coding...
(i got error in this) i catch this but... control transfered to original form...

connection coding functuion written in class file..

this connection coding function is called in remaining forms...

Wendelius22-Jan-09 23:26

22-Jan-09 23:26

Can you post the code? It doesn't matter what you do in the code, but it's important that you model the flow so that methods exit nicely and the calling method understands not to continue with execution. But as said, it's a bit hard to say more without the code.

The need to optimize rises from a bad design.My articles[^]

kulandaivel_mca200722-Jan-09 23:33

22-Jan-09 23:33

// written in class file

public void mthOpenConnection()
{
try
{

string[] datasource = File.ReadAllLines("d:\\k2.txt");

if (datasource[0] != "")
{

objprop.connection = "Data Source=" + datasource[0] + ";Initial Catalog=Inventory_VS;User ID=sa;Password=sa";

objCon = new SqlConnection(objprop.connection);

if (objCon.State != ConnectionState.Open)
{

objCon.Open();
}
}

}
catch
{

MessageBox.Show("ENTER CORRECT DATA SOURCE NAME IN UR TEXT FILE");

}

}

// this is my login form here i call my open connection

public DataSet mthGetLogin(Properties objproperties)
{
objDBconnection.mthOpenConnection();
SqlDataAdapter objDALogin = new SqlDataAdapter("sp_login", objDBconnection.objCon);
objDALogin.SelectCommand.Parameters.Add(new SqlParameter("@uname", objproperties.Username));
objDALogin.SelectCommand.Parameters.Add(new SqlParameter("@pword", objproperties.Password));
objDALogin.SelectCommand.CommandType = CommandType.StoredProcedure;
objDALogin.Fill(objDSLogin);
return objDSLogin;
}

Wendelius22-Jan-09 23:43

22-Jan-09 23:43

Okay, you could use for example bools:

public bool mthOpenConnection()
{
   try
   {
      string[] datasource = File.ReadAllLines("d:\\k2.txt");
      if (datasource[0] != "")
      {
         objprop.connection = "Data Source=" + datasource[0] + ";Initial Catalog=Inventory_VS;User ID=sa;Password=sa";
         objCon = new SqlConnection(objprop.connection);
         if (objCon.State != ConnectionState.Open)
         {
            objCon.Open();
         }
      }
   }
   catch
   {
      MessageBox.Show("ENTER CORRECT DATA SOURCE NAME IN UR TEXT FILE");
      return false;
   }
   return true;
}

and then

public DataSet mthGetLogin(Properties objproperties)
{
   if (!objDBconnection.mthOpenConnection()) 
   {
      return null;
   }
   SqlDataAdapter objDALogin = new SqlDataAdapter("sp_login", objDBconnection.objCon);
   objDALogin.SelectCommand.Parameters.Add(new SqlParameter("@uname", objproperties.Username));
   objDALogin.SelectCommand.Parameters.Add(new SqlParameter("@pword", objproperties.Password));
   objDALogin.SelectCommand.CommandType = CommandType.StoredProcedure;
   objDALogin.Fill(objDSLogin);
   return objDSLogin;
}

The need to optimize rises from a bad design.My articles[^]

kulandaivel_mca200723-Jan-09 0:07

23-Jan-09 0:07

it works fine...

but the flow didn't stoped bcz next consequetive lines needs valid open connection...
(but i catch invalid connection in my try block)(contradictory)

it ends in error...

Wendelius23-Jan-09 0:16

23-Jan-09 0:16

If you added the modification to mthGetLogin that I wrote, the execution in that method won't continue because I added return null to it. However, this is only part of your code so you must use this idea in all places where you want to 'break' the execution

The need to optimize rises from a bad design.My articles[^]

kulandaivel_mca200723-Jan-09 0:21

23-Jan-09 0:21

s u r right...

see this peace of code...
this is my loging forms's button(submit) click event...

when the program try to read table values error occurs...

private void button2_Click_1(object sender, EventArgs e)
{

objproperties.Username = txtuname.Text;
objproperties.Password = txtpword.Text;
objDSLogin = objfunction.mthGetLogin(objproperties);
if (objDSLogin.Tables[0].Rows.Count > 0)
{
if (objDSLogin.Tables[0].Rows[0]["status"].ToString() == "User")
{
objproperties.Username = txtuname.Text;
objfunction.mthUsernameInsert(objproperties);
this.Hide();
UserForm uf = new UserForm();
uf.Show();

}
else if (objDSLogin.Tables[0].Rows[0]["status"].ToString() == "Admin")
{
this.Hide();
AdminForm1 af = new AdminForm1();
af.Show();
}

else
{
label4.Text = "Login Failed... Try Again";
label4.Visible = true;
txtpword.Text = "";
txtuname.Focus();

}

}
else
{
label4.Visible = true;
txtpword.Text = "";
txtuname.Focus();

}

}

Wendelius23-Jan-09 0:57

23-Jan-09 0:57

So based on the previous example I wrote, you could:

...
objproperties.Password = txtpword.Text;
objDSLogin = objfunction.mthGetLogin(objproperties);
if (objDSLogin == null) 
{
   return;
}
if (objDSLogin.Tables[0].Rows.Count > 0)
{
...

The need to optimize rises from a bad design.My articles[^]

kulandaivel_mca200723-Jan-09 0:15

23-Jan-09 0:15

is anyother way available....

like goto,break,Abandon...

Wendelius23-Jan-09 0:18

23-Jan-09 0:18

goto can go only to a specific point inside a method. break exits a loop so there's no quick way to do this. One way is to throw an exception inside a catch. Then catch this exception at the level you want.

The need to optimize rises from a bad design.My articles[^]

kulandaivel_mca200723-Jan-09 0:22

23-Jan-09 0:22

how i can do this...
guide me..

kulandaivel_mca200723-Jan-09 0:57

23-Jan-09 0:57

public bool mthOpenConnection()
{
try
{
objprop.J = 0;

string[] datasource = File.ReadAllLines("d:\\k2.txt");

if (datasource[0] != "")
{
objprop.connection = "Data Source=" + datasource[0] + ";Initial Catalog=Inventory_VS;User ID=sa;Password=sa";

objCon = new SqlConnection(objprop.connection);

if (objCon.State != ConnectionState.Open)
{

objCon.Open();
}
}

}
catch (Exception ex)
{
MessageBox.Show("ENTER CORRECT DATA SOURCE NAME IN UR TEXT FILE");
return false;
}
return true;
}

how i can throw my exceptions....

message box

vedharadha22-Jan-09 20:14

vedharadha

22-Jan-09 20:14

how 2 display message to user in class file...(windows app using c#)

messagebox.show is not working.

VenkatFor.NET22-Jan-09 20:31

VenkatFor.NET

22-Jan-09 20:31

In c#, MessageBox.Show() should work. Check the case of the statement you have. C# is case sensitive.

Bhaskara

vedharadha22-Jan-09 20:34

vedharadha

22-Jan-09 20:34

in c# message box is working. it is not a problem. im using it in class file..

VenkatFor.NET22-Jan-09 20:46

VenkatFor.NET

22-Jan-09 20:46

You cannot have a messagebox displayed in a class file.

Bhaskara

Wendelius22-Jan-09 20:40

22-Jan-09 20:40

What do you mean by saying that messagebox is not working?

The need to optimize rises from a bad design.My articles[^]

vedharadha22-Jan-09 20:52

vedharadha

22-Jan-09 20:52

if i type sqlconnection in my form it will shows the functions starts with letter "s"(sqlcommmand,sqladaptorm,reader) and sqlconnection also...

when i type messagebox.show the option messagebox.show did not displayed

VenkatFor.NET22-Jan-09 20:58

VenkatFor.NET

22-Jan-09 20:58

In class library project, reference to System.Windows.Forms is not added. MessageBox is a class that is available in System.Windows.Forms namespace which is only added to the windows applications.

Bhaskara

Wendelius22-Jan-09 21:00