Equivalent of C# ?

In VB.NET I use this

VB Code:

Public Shared Sub OpenDB()
If Not MyConnection.State = ConnectionState.Open Then
 MyConnection.Open()
Else
msgbox ("Connection already open ")
End If
End Sub

What's C# equivalent ?
Thanx

I stuck only in the (if not ) clause ?? I know everything else !

This is off the top of my head, and very well have some problems with it...

Code:

---

public static void OpenDB()
{
  if(!(MyConnection.State == ConnectionState.Open))
  {
      MyConnection.Open();
  }
  else
  {
      MessageBox.Show("Connection already open");
  }
}

---

Thanx for this fast response !:D

again what's C# equivalent for (nothing) keyword . I couldn't figure it out !

VB Code:

Dim Tables As DataTable = MyConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, New Object() {Nothing, Nothing, Nothing, "TABLE"})

thanx

No problem, it worked for what you wanted?

never mind , it's null . Next time I should have a look at C# Keywords . :D

Quote:

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Originally posted by hellswraith
No problem, it worked for what you wanted?

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yeah worked fine . :D btw , how can import class1 data members ?
in vb.net we do this :

import Class1.Myclass.Myfunction

thanx !

I'm just a newbie but I thought it was the using keyword

Code:

---

using Namespace.Class blah blah blah

---

Mabe that'll help a little bit :cool:

Quote:

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Originally posted by Cagez
I'm just a newbie but I thought it was the using keyword

Code:

---

using Namespace.Class blah blah blah

---

Mabe that'll help a little bit :cool:

---

Nope !

Not sure exactly what you need. I would have said the using statement myself, but it seems like you are doing something different. Give some more VB code that shows how your using it so I can understand better what your asking.

Quote:

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Originally posted by Pirate
yeah worked fine . :D btw , how can import class1 data members ?
in vb.net we do this :

import Class1.Myclass.Myfunction
thanx !

---

I thought the post explain itself :rolleyes:
How can I shorten a function path . for example

I can do this , so I don't have to continue typing the whole path to IO members

Import System.IO.

Path.method (instead of doing this System.IO.Path.method

Clear ?? :rolleyes:

You can use the 'using' directive:

Code:

---

using System.IO;

---

Quote:

---

Originally posted by SimonVega
You can use the 'using' directive:

Code:

---

using System.IO;

---

---

IO class was only example . I need to import (using in C#) classes and voids from Class1 . What should I do ?

I've been trying this but with no luck

I want to get this :
using Class1.Mydatabase.OpenDB

come on guys this is easy ! This is my first day with C# ! It was the worst .

I think I know where your stuck. When using static members, you have to reference the member using the class name:

Code:

---

  public class HelloWorld
  {
        public static void DisplayMsg()
        {
            Console.Write("Hello World");
        } 

        static void Main()
        {
            //Note: You can not use an object reference
            HelloWorld.DisplayMsg();
        } 
    }

---

Welcome to the dark side! :D

I should explained that well ! I do this everyday in VB.NET . I don't know if I can do this in C# ??
I have a namespace called "Mydatabase" and one big class called "DBClass" and many functions under "DBClass" class .
all of them are static (shared) . I call them in form1 like so :

Code:

---

Mydatabase.DBClass.OpenDB();

---

how can I shorten the its name to be called like this :

Code:

---

OpenDB();

---

I believe it can be done by using Keyword but I couldn't find it there ?

Sorry if I'm becoming repetitive, but have you tried this?

Code:

---

using Mydatabase.DBClass;

---

It should go at the very top of your form code, where the other using statements are.

I already covered this a few threads up. There is no such thing as global functions in C#. To reference a static member of a class, you have to use the class name following by the dot notation...

Quote:

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It should go at the very top of your form code, where the other using statements are.

---

You can only apply the using namespace directive against namespaces, not classes.

Cagez , yes I've tried that but it seem SimonVega is right . It's only applied to namespaces ! but how come this happens :

Code:

---

using System.Windows.Forms.Design

---

System is namespace but others are classes ???
C# is confusing to me at least . VB.NET can do such stuff easily !:D

Class1.cs(73): Type and identifier are both required in a foreach statement

what's wrong with this code ??

Code:

---

public static void LoadTables (System.Windows.Forms.TreeView TreView)
                        {
                                OpenDB.OpenDB1();
                                DataTable Tables =MyConnection().GetOleDbSchemaTable(OleDbSchemaGuid.Tables,new object[] {null,null,null,"TABLE"});
                                CloseDB.CloseDB1 ();

                                if (Tables.Rows.Count > 0)
                                {
                                        TreView.BeginUpdate ();
                                }
                                        DataRow dr;
                                foreach (dr in Tables.Rows)
                                {
                                        TreView.Nodes.Add (new  TreeNode(dr("TABLE_NAME")));
                                }
                                Tables = null;
                        }

---

it shows blue line on "in" word . Why ?

You have to specify the type in the foreach construct:

Code:

---

foreach(DataRow r in t.Rows)
    Console.WriteLine(r[0]);

---

Code:

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using System.Windows.Forms.Design

---

Quote:

---

System is namespace but others are classes ???

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'System.Windows.Forms.Design' is a nested namespace.

This is VB version

VB Code:

'TreeView
            Public Overloads Shared Sub LoadTables(ByVal TreView As TreeView)
                'see if connection is already open
                OpenDB.OpenDB()
                Dim Tables As DataTable = MyConnection.GetOleDbSchemaTable(OleDb.OleDbSchemaGuid.Tables, _
                New Object() {Nothing, Nothing, Nothing, "TABLE"})
 
                CloseDB.CloseDB()
 
                '"TABLE_CATALOG" is the database name
                '"TABLE_NAME" is the table name
                If Tables.Rows.Count > 0 Then
                    TreView.BeginUpdate()
                    Dim dr As DataRow
                    For Each dr In Tables.Rows
                                                TreView.Nodes.Add(New TreeNode(dr("TABLE_NAME")))
Next
TreView.EndUpdate()
End If
Tables = Nothing
End Sub

I've tried your way SimonVega but gave me error :
Class1.cs(77): 'dr' denotes a 'variable' where a 'method' was expected
in this line

Code:

---

TreView.Nodes.Add (new TreeNode(dr()("TABLE_NAME")));

---

Thank you for trying to solve my problem !

This is what you were supposed to change:

Code:

---

foreach (DataRow dr in Tables.Rows) {
    TreView.Nodes.Add (new  TreeNode(dr("TABLE_NAME")));
}

---

No , that didn't help ! Still getting that error !

Class1.cs(77): 'dr' denotes a 'variable' where a 'method' was expected
in this line

Code:

---

foreach (DataRow dr in Tables.Rows) {
    TreView.Nodes.Add (new  TreeNode(dr("TABLE_NAME")));
}

---

any help guys ??

There is also another syntax error in your code:

Code:

---

foreach (DataRow dr in Tables.Rows) {
    TreView.Nodes.Add (new  TreeNode(dr["TABLE_NAME"]));
}

---

You need to reference the indexer using squar brackets.

Sorry didn't work either . I got these errors when I tried your code !

1- Class1.cs(76): The best overloaded method match for 'System.Windows.Forms.TreeNode.TreeNode(System.Windows.Forms.TreeView)' has some invalid arguments

2-Class1.cs(76): Argument '1': cannot convert from 'object' to 'System.Windows.Forms.TreeView'

:rolleyes: . any suggestions plz ??

Ok...I was merely checking your syntax, not actually running the code. I'm not at my dev box, but here is why i think it is not compiling. When you read the column data out from the data row, use the tostring() method to convert it to a string.

Code:

---

foreach (DataRow dr in Tables.Rows) {
    TreView.Nodes.Add (new TreeNode(dr["TABLE_NAME"].ToString()));
}

---

I got a lot of errors . I believe it's not conversion problem ! it has to do with "in" till the end . Dunno really I though that was simple .

Code:

---

public static void LoadTables (System.Windows.Forms.TreeView TreView)
                        {
                                OpenDB.OpenDB1();
                                DataTable Tables =MyConnection().GetOleDbSchemaTable(OleDbSchemaGuid.Tables,new object[] {null,null,null,"TABLE"});
                                CloseDB.CloseDB1 ();

                                if (Tables.Rows.Count > 0)
                                {
                                        TreView.BeginUpdate ();
                                }
                                DataRow dr;
                               
                                foreach (dr in Tables.Rows())
                                {
                                        TreView.Nodes.Add (new  TreeNode(dr("TABLE_NAME")));
                                }
      Tables = null;
}

---

I appreciate your help SimonVega .
Thank you

Here is a sample I just wrote up that works and your code should somewhat resemble:

Code:

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private void button1_Click(object sender, System.EventArgs e) {
    DataTable t = new DataTable();
    DataRow r = t.NewRow();
    t.Columns.Add("ID", typeof(System.Int32));
    r[0] = 10;
    t.Rows.Add(r);

    TreeNode root = treeView1.Nodes.Add("Root");
    foreach(DataRow row in t.Rows)
        root.Nodes.Add(new TreeNode(row["ID"].ToString()));       
}

---

Didn't help either ! It gives me a different error , seems simpler but I coudn't solve it though !

Class1.cs(78): 'dr' denotes a 'variable' where a 'method' was expected

Code:

---

foreach (DataRow dr in Tables.Rows)
{
root = TreView.Nodes.Add("Root");       
TreView.Nodes.Add(new TreeNode(dr("TABLE_NAME")));
//nor this
//TreView.Nodes.Add(new TreeNode(dr()("TABLE_NAME")));
}

---

Thanx dude !