Recently I need to show multi-line string in a datagridview cell. To achieve that we need to write code in CellFormatting event of DataGridview. Following is the code

        private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            if (e.Value.Equals("Error"))
            {
                e.CellStyle.BackColor = Color.Red;
                e.CellStyle.ForeColor = Color.White;

            }
            else
            {
                if ((!e.Value.Equals("OK")) && e.ColumnIndex==2)
                {
                    e.CellStyle.BackColor = Color.Green;
                    e.CellStyle.ForeColor = Color.White;
                    e.CellStyle.WrapMode = DataGridViewTriState.True;
                    dataGridView1.Columns[2].AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells;
                    dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells;

                }

            }
        }

I hope this help!

Kshitij

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Hi,

Few days back i needed a code snippet to write a text in starting of all files in a directory. Searched net but could not find any working code. Then i decide to write my own code and come up with following code.

I hope this will help guys who are looking to do same.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace AddTextToFiles
{
    class Program
    {
        private static DirectoryInfo ds;
        static void Main(string[] args)
        {
            Console.WriteLine("*********************Written By Kshitij Sharma ***********************");
            Console.WriteLine("Please Enter the path and Press enter ");
            string sPath = Console.ReadLine();
            Console.WriteLine("Please Enter <B style="BACKGROUND-COLOR: #a0ffff; COLOR: black">Text</B> ");
            string sText = Console.ReadLine();
            addText(sPath,sText);
            Console.WriteLine("*****************Reach Me @ k.sharma78@gmail.com****************");
            Console.Read();
        }

        private static void addText(string pth,string txt)
        {
            try
            {

                if (!string.IsNullOrEmpty(pth))
                {
                    ds = new DirectoryInfo(pth);
                }
                else
                {
                    ds = new DirectoryInfo("c:\\testfiles");
                }
                if (string.IsNullOrEmpty(txt))
                {
                    txt = "<!--#Include File=\"CheckSQL.inc\"-->";
                }
                foreach (FileInfo f in ds.GetFiles("*.asp"))
                {
                    Console.WriteLine("Writing to file-->" + f.Name);
                    string strPath = ds.Root + ds.Name + "\\" + f.Name;
                    StreamReader sr = new StreamReader(strPath);
                    string fileContent = sr.ReadToEnd();
                    sr.Close();
                    StreamWriter sw = new StreamWriter(strPath, false);
                    StringReader gr = new StringReader(fileContent);
                    sw.WriteLine(txt);
                    sw.WriteLine(gr.ReadToEnd());
                    sw.Close();
                }
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.Read();
            }
        }
    }
}

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let’s code our ReflectionTest Class

Namespace reflectionclass
Public Class ClsReflection

#Region "Methods"
Public Function add(ByVal x As Integer, ByVal y As Integer) As Integer
Return x + y
End Function

Public Function [sub](ByVal x As Integer, ByVal y As Integer) As Integer
Return x - y
End Function
#End Region

End Class
End Namespace

let’s make a test project now. Add a windows form application to the solution.

Now let’s design our Form.

so after putting two command buttons two listview controls and four textbox controls our form should look like this.

Let’s code our form now

Imports System.Reflection

Public Class Form1
Dim objAssembly As Assembly
'Declare an array of Types to Hold All Classes of Assembly
Dim arrTypes As Type()
Dim objType As Type
'Delcare an array to hold all methods of Assembly
Dim arrMethods As MethodInfo()
Dim objMethod As MethodInfo

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Try
OpenFileDialog1.ShowDialog()
txtAssembly.Text = OpenFileDialog1.FileName
objAssembly = System.Reflection.Assembly.LoadFrom(txtAssembly.Text)
For Each cls In objAssembly.GetTypes
'
If cls.FullName.IndexOf("ClsReflection") > 0 Then
lstClasses.Items.Add(cls.FullName)
End If
Next
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub

Private Sub lstClasses_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstClasses.SelectedIndexChanged
Try
lstMethods.Items.Clear()
objType = objAssembly.GetType(Me.lstClasses.SelectedItem.ToString)
arrMethods = objType.GetMethods
For Each method In objType.GetMethods
lstMethods.Items.Add(method.Name)
Next
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub

Private Sub cmdCallMethod_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdCallMethod.Click
Try
objMethod = objType.GetMethod(lstMethods.SelectedItem.ToString())
Dim obj As Object
obj = Activator.CreateInstance(objType)
'Let's Create Array of Parameter
Dim objParameters As Object() = {Int32.Parse(txtNum1.Text), Int32.Parse(txtNum2.Text)}
'If there is no parameter in method then on the place of oo pass the null
txtResult.Text = objMethod.Invoke(obj, objParameters).ToString()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
End Class

Select Add and put any two numbers in the first and second number textbox and click on execute method and you should get the result.

Now select Sub and enter any two number in first number and second number textbox and press execute method and you should get the desired result.

If you have any point you are not getting in this article please let me know i will try to explain.

Happy Coding!

Kshitij

• Basically in a database management system (DBMS), a stored procedure is a set of Structured Query Language (SQL) statements with an assigned name that’s stored in the database in compiled form so that it can be shared by a number of programs. The use of stored procedures can be helpful in controlling access to data (end-users may enter or change data but do not write procedures), preserving data integrity (information is entered in a consistent manner), and improving productivity (statements in a stored procedure only need to be written one time). Stored procedures have been part of Oracle, MS SQL Server, DB-2, postgreSQL and others for years but MySQL introduce Store procedures recently in version 5.xxx. MySQL stored procedures are very similar to the DB2 implementation, as both are based on the SQL:2003 standard.

Why i need store procedure when i can write Queries on page/forms  :

• Consider a scenario in which you have a client/server application with centrally located database server and your application has a provision to create a voucher and you calculate tax on the amount of the voucher. What if you need to change tax rate. Either you have to change code in your form to recalculate the tax and then you need to reinstall your forms on each of the client machine or you have an option to create a procedure that calculate tax and call that procedure from your client application and that’s it. Because your application call the procedure to calculate tax you don’t need to reinstall your BO (Business Objects) or client application to each of client machine. All you need to do is to change code in your procedure that calculate Tax.
• They can reduce network traffic. Complex, repetitive tasks may require getting results, applying some logic to them, and using this to get more results. If this only has to be done on the database server, there is no need to send result sets and new queries back and forth from application server to database server. Network traffic is a common bottleneck causing performance issues, and stored procedures can help reduce this. More often though, it is the database server itself that is the bottleneck, so this may not be much of an advantage.

Let’s Start with a simple Example:

As i described earlier a store procedure is a set of SQL Statement. Almost any valid SQL Statement can go inside a store procedure, with a few exceptions, which we will look later. I am using MySQL command line utility to write and execute procedures. You can also use MySQL Query Browser to create/modify/delete procedures. It comes with MySQL GUI Tools which are freely available on MySQL Site.

use test; #Select Database
CREATE PROCEDURE usp_test() SELECT ‘SP Test ‘ as Title;
This line will add a procedure called “usp_test” in your selected database which in this case is Test. Note i use ‘usp’  (User store procedure) as a prefix to procedure just to distinct it with system procedures.
Now let’s call our newly created store procedure by using call keyword.
Call usp_test();
if you run this from MySQL command line utility you will get something like :

The procedure we just create is hardly useful, but the basics are there. CREATE PROCEDURE sp_name() will define the procedure, and CALL sp_name() will call the procedure.

Let’s move ahead : Parameters

The real benefit of a stored procedure is when you can pass values to it, as well as retrieve information back. The concept of parameters should be familiar to anyone who has had experience with any procedural programming experience.

There are three types of parameter:

• IN: The default. This parameter is passed to the procedure, and can change inside the procedure, but remains unchanged outside.
• OUT: No value is supplied to the procedure (it is assumed to be NULL), but it can be modified inside the procedure, and is available outside the procedure.
• INOUT: The characteristics of both IN and OUT parameters. A value can be passed to the procedure, modified there as well as passed back again.

An IN Example:

Here is an example of a stored procedure demonstrating the use of an IN parameter. Since IN is the default, there is no need to specify the parameter as such.

mysql> CREATE PROCEDURE USP_IN(p VARCHAR(10)) SET @Name = P;
mysql> CALL USP_IN(‘KSHITIJ SHARMA’);
mysql> SELECT @Name;

And you should get something like

The session variable @Name is set inside of the procedure, based upon the parameter P, which is passed to the procedure, and remains unchanged.

An Out Example:

Here I reset @Name just to make sure the final result is not a legacy of the previous procedure. This time, the parameter P is changed inside of the procedure, while the session variable is passed to the procedure, ready to receive the result.

An In-Out Example:

Here, a parameter is passed to the procedure, used in the calculation, and the results are made available to the session variable @Y.

Getting Information from Database :

mysql> SHOW PROCEDURE STATUS;mysql> SELECT * FROM INFORMATION_SCHEMA.ROUTINES;

Let’s do a bit more complex example :

First, we will create a sample table.

mysql> CREATE table tmptest(id INT, txt VARCHAR(10), PRIMARY KEY(id));
Query OK, 0 rows affected (0.11 sec)

Delimiters, and multi-statement procedures

Stored procedures of course are not that useful if they are just one statement. The effects of all the procedures we have looked at so far could have had been duplicated much more easily with a single SQL statement. Useful procedures are much longer than that. Those of you who are on the ball may be thinking of a complication. How can we differentiate between multiple statements inside the procedure, and the end of the procedure? We have to create a different delimiter to end the CREATE PROCEDURE statement. Here is how:

mysql> DELIMITER $$

Note that there is no semicolon after the ‘$$’ symbol, which we will use as the delimiter for our purposes. You have to choose a delimiter that does not appear in your procedure, and it can be more than one character.

mysql> CREATE PROCEDURE usp_ins (P VARCHAR(10))
    -> BEGIN
    ->  SET @x=CHAR_LENGTH(P);
    ->  SET @y = HEX(P);
    ->  INSERT INTO tmptest(id,txt) VALUES(@x,@y);
    -> END$$
Query OK, 0 rows affected (0.05 sec)

mysql> CALL usp_ins('ABC');
    -> $$
Query OK, 1 row affected (0.00 sec)

mysql> DELIMITER ;
mysql> SELECT * FROM tmptest;
*************************** 1. row ***************************
 id: 3
txt: 414243
1 row in set (0.00 sec)

Note what happened when we tried to call the procedure. Because MySQL was still using the $$ symbol as a delimiter, and not the semicolon, the statement did not run after the semicolon. We first needed to close it with the piping symbol. Afterwards, we reset the delimiter back to normal, and test that the records were correctly added to the tmptest table.

Procedure Variables:

You can DECLARE variables that exist only inside the procedure, as well as assign values to them with the SET statement without using the ‘@’ symbol, required for session variables. Here is how:

mysql> DELIMITER $$

mysql> CREATE PROCEDURE usp_variables (P INT)

-> BEGIN->  DECLARE a INT;
->  DECLARE b INT DEFAULT 10;
->  SET a = P*b;->  INSERT INTO tmptest(id,txt) VALUES(a,HEX('DEF'));
-> END$$ 

Query OK, 0 rows affected (0.00 sec) 

mysql> DELIMITER ;
mysql> CALL usp_variables(4);
Query OK, 1 row affected (0.00 sec) 
mysql> SELECT * FROM tmptest;
*************************** 1. row ***************************
 id: 3
txt: 414243
*************************** 2. row ***************************
 id: 40
txt: 444546
2 rows in set (0.00 sec)

if you declare a variable without default (such as a ) it will be set to NULL.

Populating Variables from table.

mysql> DELIMITER $$
mysql> CREATE PROCEDURE usp_selectINvariable ()
    -> BEGIN
    ->  DECLARE a INT;
    ->  DECLARE b VARCHAR(10);
    ->  SELECT id,txt INTO a,b FROM tmptest LIMIT 1;
    ->  SELECT a,b;
    -> END|
Query OK, 0 rows affected (0.00 sec)

mysql> DELIMITER ;
mysql> CALL usp_selectINvariable();
*************************** 1. row ***************************
a: 3
b: 414243
1 row in set (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

see how i limit the result to single  (LIMIT 1)  record. In next post i will show you how to iterate multiple records.

I hope you can now write your own store procedure in MySQL.  In next post of this series i will show you more complex topics, to show some of the real power of store procedures.

Kshitij

Now rename your service1.vb file to PingBackSvr.vb and add another class code file to your project and name it PingBack.vb. After doing this your solution explorer should look like

Now lets start code PingBack.vb

'Namespace References
Imports System
Imports System.Runtime.InteropServices
Imports System.Net
Imports System.Net.NetworkInformation
Imports System.Net.Sockets

Public Class PingBack

<DllImport("wininet", CharSet:=CharSet.Auto)> _
Private Shared Function InternetGetConnectedState(ByRef flags As ConnectionStatusEnum, ByVal dw As Integer) As Boolean
End Function

''' <summary>
''' enum to hold the possible connection states
''' </summary>
<Flags()> _
Private Enum ConnectionStatusEnum As Integer
INTERNET_CONNECTION_MODEM = &H1
INTERNET_CONNECTION_LAN = &H2
INTERNET_CONNECTION_PROXY = &H4
INTERNET_RAS_INSTALLED = &H10
INTERNET_CONNECTION_OFFLINE = &H20
INTERNET_CONNECTION_CONFIGURED = &H40
End Enum

''' <summary>
''' method to check the status of the pinging machines internet connection
''' </summary>
''' <returns></returns>
Private Function HasConnection() As Boolean
'instance of out ConnectionStatusEnum
Dim state As ConnectionStatusEnum = 0

'call the API
InternetGetConnectedState(state, 0)

'check the status, if not offline and the returned state
'isnt 0 then we have a connection
If (CInt(ConnectionStatusEnum.INTERNET_CONNECTION_OFFLINE) And CInt(state)) <> 0 Then
'return true, we have a connection
Return False
End If
'return false, no connection available
Return True
End Function

''' <summary>
''' method for retrieving the IP address from the host provided
''' </summary>
''' <param name="host">the host we need the address for</param>
''' <returns></returns>
Private Function GetIpFromHost(ByRef host As String) As IPAddress
Dim returnMessage As String = String.Empty
'IPAddress instance for holding the returned host
Dim address As IPAddress = Nothing

'wrap the attempt in a try..catch to capture
'any exceptions that may occur
Try
'get the host IP from the name provided
address = Dns.GetHostEntry(host).AddressList(0)
Catch ex As SocketException
'some DNS error happened, return the message
returnMessage = String.Format("DNS Error: {0}", ex.Message)
End Try
Return address
End Function

''' <summary>
''' method to check the ping status of a provided host
''' </summary>
''' <param name="host">the host we need to ping</param>
''' <returns></returns>
Protected Friend Function CheckSiteStatus(ByVal host As String) As String
'string to hold our return messge
Dim returnMessage As String = String.Empty

'IPAddress instance for holding the returned host
Dim address As IPAddress = GetIpFromHost(host)

'set the ping options, TTL 128
Dim options As New PingOptions(128, True)

'create a new ping instance
Dim ping As New Ping()

'32 byte buffer
Dim data As Byte() = New Byte(31) {}

'first make sure we actually have an internet connection
If HasConnection() Then
'here we will ping the host 4 times (standard)
For i As Integer = 0 To 3
Try
'send the ping 4 times to the host and record the returned data
Dim reply As PingReply = ping.Send(address, 1000, data, options)

'make sure we dont have a null reply
If Not (reply Is Nothing) Then
Select Case reply.Status
Case IPStatus.Success
returnMessage = String.Format("Reply from {0}: bytes={1} time={2}ms TTL={3}", reply.Address, reply.Buffer.Length, reply.RoundtripTime, reply.Options.Ttl)
Exit Select
Case IPStatus.TimedOut
returnMessage = "Connection has timed out..."
Exit Select
Case Else
returnMessage = String.Format("Ping failed: {0}", reply.Status.ToString())
Exit Select
End Select
Else
returnMessage = "Connection failed for an unknown reason..."
End If
Catch ex As PingException
returnMessage = String.Format("Connection Error: {0}", ex.Message)
Catch ex As SocketException
returnMessage = String.Format("Connection Error: {0}", ex.Message)
End Try
Next
Else
returnMessage = "No Internet connection found..."
End If

'return the message
Return returnMessage
End Function
End Class

Now let’s code our Service class which in this case is PinbBackSvr.vb.

Public Class PingBackSvr
Private _objPingback As PingBack
Private _status As String
Private WithEvents timer1 As New System.Timers.Timer
Private PingLog As New EventLog
Protected Overrides Sub OnStart(ByVal args() As String)
' Add code here to start your service. This method should set things
' in motion so your service can do its work.
'Uncomment this line to Debug this service
Debugger.Launch()
timer1.Enabled = True
timer1.Interval = 6000
' Me.TracePing()
End Sub

Protected Overrides Sub OnStop()
' Add code here to perform any tear-down necessary to stop your service.
Me.Timer1.Enabled = False
End Sub

Private Sub OnTimerElapsed(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles timer1.Elapsed
Me.TracePing()
End Sub

Private Sub TracePing()
Try
If Not Diagnostics.EventLog.SourceExists("PingBackSvr") Then
Diagnostics.EventLog.CreateEventSource("PingBackSvr", "KshitijSharma.Net Ping Service Log")
End If
PingLog.Source = "PingBackSvr"
Me._objPingback = New PingBack
Me._status = Me._objPingback.CheckSiteStatus("www.kshitijsharma.net")
If InStr(Me._status, "failed") > 0 OrElse InStr(Me._status, "Error") > 0 OrElse InStr(Me._status, "timed out") > 0 Then
PingLog.WriteEntry(Me._status, EventLogEntryType.FailureAudit)
Else
PingLog.WriteEntry(Me._status, EventLogEntryType.SuccessAudit)
End If
Catch ex As Exception
PingLog.WriteEntry(ex.Message, EventLogEntryType.Error)
Finally
Me._objPingback = Nothing
PingLog = Nothing
End Try
End Sub
End Class

Now add a ‘Service Installer by right clicking design view of service.

Now Build your project

After building this service we need to install it on server.  we can do this with installUtil.exe utility. you can use

To Install
<pathofInstallUtil>\installUtil.exe /i <pathtoyourexe>

To Uninstall
<pathofInstallUtil>\installUtil.exe /u <pathtoyourexe>

Please let me know if you need help any part of this code!
Enjoy Coding!
Kshitij

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