C#

private void Form1_Load(object sender, EventArgs e)
{
    // TODO: This line of code loads data into the 'klantenbestandDataSet4.Logo' table. You can move, or remove it, as needed.
    this.logoTableAdapter.Fill(this.klantenbestandDataSet4.Logo);
    // TODO: This line of code loads data into the 'klantenbestandDataSet3.Producten' table. You can move, or remove it, as needed.
    this.productenTableAdapter.Fill(this.klantenbestandDataSet3.Producten);
    // TODO: This line of code loads data into the 'klantenbestandDataSet1.OrderWerkzaamheden' table. You can move, or remove it, as needed.
    //this.orderWerkzaamhedenTableAdapter.Fill(this.klantenbestandDataSet1.OrderWerkzaamheden);
    // TODO: This line of code loads data into the 'klantenbestandDataSet2.Werkzaamheden' table. You can move, or remove it, as needed.
    this.werkzaamhedenTableAdapter1.Fill(this.klantenbestandDataSet2.Werkzaamheden);
    // TODO: This line of code loads data into the 'klantenbestandDataSet1.Werkzaamheden' table. You can move, or remove it, as needed.
    //this.werkzaamhedenTableAdapter.Fill(this.klantenbestandDataSet1.Werkzaamheden);
    // TODO: This line of code loads data into the 'klantenbestandDataSet1.Klanten' table. You can move, or remove it, as needed.
    this.klantenTableAdapter.Fill(this.klantenbestandDataSet1.Klanten);
    //cn.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\klantenbestand.mdb"; //goed
    cn.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\Master of Disaster\Documents\klantenbestand.mdb"; //goed
    cmd.Connection = cn;

    // hier worden de methodes aangeroepen  de gegevens laden onder instellingen.
    werkzaamhedenwijzigenonderinstellingen();
    productenwijzigenonderinstellingen();

    //hier worden de methode aangeroepen voor het laden van het pad van het gebruikte logo
    PlaatsenLogo();

    //Hier zet hij het plaatje neer als logo
    //textBox63.Text=@"C:\Users\Master of Disaster\Pictures\wendy\beeldschoon.png";
    pictureBox1.ImageLocation = textBox63.Text;
    //pictureBox1.ImageLocation = @"C:\Users\Master of Disaster\Pictures\wendy\beeldschoon.png"; //---> werkt

    // Hide the tab page
    tabControl1.TabPages.Remove(tabPage6);
}

private void PlaatsenLogo()
{
    // Hier wordt de connectie gemaakt.
    try
    {
        string q = "SELECT LogoPad from Logo WHERE PadId=1";
        //string q = "SELECT Kolomnaam " + Environment.NewLine + "INTO [ExcelTabbladNaam] IN '' [Excel 8.0;Database=" + Environment.CurrentDirectory  + "\\\\Klanten.xls]" + Environment.NewLine + "FROM Klanten"; //goed
        //string q = "SELECT Kolomnaam " + "\n" + "INTO [ExcelTabbladNaam] IN '' [Excel 8.0;Database="C:\Klanten.xls]"" + ""\n"" + "FROM BronTabelnaam";
        cmd.CommandText = q;
        cn.Open();
        dr = cmd.ExecuteReader();
        if (dr.HasRows)
        {
            DataTable dt = new DataTable();
            dt.Load(dr);
            dataGridView18.DataSource = dt;

        }
    }
    catch (Exception e)
    {
        cn.Close();
        MessageBox.Show(e.Message.ToString());
    }
    cn.Close();
}

private void dataGridView18_SelectionChanged(object sender, EventArgs e)
{
    if (dataGridView18.SelectedRows.Count > 0)
    {
        DataGridViewRow dr = dataGridView18.SelectedRows[0];
        textBox63.Text = dr.Cells[0].Value.ToString(); // pad

    }
}

<xml version="1.0"?>
<!--
    Note: As an alternative to hand editing this file you can use the
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in
    machine.config.comments usually located in
    \Windows\Microsoft.Net\Framework\v2.x\Config
-->
<configuration>
    <configSections>
        <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
            <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
                <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
                <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
                    <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/>
                    <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
                    <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
                    <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
                </sectionGroup>
            </sectionGroup>
        </sectionGroup>
    </configSections>
    <appSettings/>
    <connectionStrings/>
    <system.web>
        <!--
            Set compilation debug="true" to insert debugging
            symbols into the compiled page. Because this
            affects performance, set this value to true only
            during development.
        -->
        <compilation debug="true">
            <assemblies>
                <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
                <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            </assemblies>
        </compilation>
        <!--
            The <authentication> section enables configuration
            of the security authentication mode used by
            ASP.NET to identify an incoming user.
        -->
        <authentication mode="Windows"/>
        <!--
            The <customErrors> section enables configuration
            of what to do if/when an unhandled error occurs
            during the execution of a request. Specifically,
            it enables developers to configure html error pages
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
        <pages>
            <controls>
                <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            </controls>
        </pages>
        <httpHandlers>
            <remove verb="*" path="*.asmx"/>
            <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
        </httpHandlers>
        <httpModules>
            <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        </httpModules>
    </system.web>
    <system.codedom>
        <compilers>
            <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                <providerOption name="CompilerVersion" value="v3.5"/>
                <providerOption name="WarnAsError" value="false"/>
            </compiler>
        </compilers>
    </system.codedom>
    <!--
        The system.webServer section is required for running ASP.NET AJAX under Internet
        Information Services 7.0.  It is not necessary for previous version of IIS.
    -->
    <system.webServer>
        <validation validateIntegratedModeConfiguration="false"/>
        <modules>
            <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        </modules>
        <handlers>
            <remove name="WebServiceHandlerFactory-Integrated"/>
            <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        </handlers>
    </system.webServer>
    <system.serviceModel>
        <services>
            <service behaviorConfiguration="BooksServices.Service1Behavior" name="BooksServices.BooksService">
                <endpoint address="" binding="basicHttpBinding" contract="BooksServices.IBooksService">
                </endpoint>
                <host>
                &lt;baseAddresses>
                <add baseAddress="http://192.168.178.30:50501/BooksService.svc"/>
                &lt;/baseAddresses>
                </host>

                <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
            </service>
        </services>
        <behaviors>
            <serviceBehaviors>
                <behavior name="BooksServices.Service1Behavior">
                    <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
                    <serviceMetadata httpGetEnabled="true"/>
                    <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
                    <serviceDebug includeExceptionDetailInFaults="false"/>
                </behavior>
            </serviceBehaviors>
        </behaviors>
    </system.serviceModel>
</configuration>

DataView DV = new DataView(dbDataSet);
DV.RowFilter = string.Format("Name LIKE '%{0}'", textBox1.Text);
dataGridView1.DataSource = DV;

private void LoadGrid()
        {
            selection sel = new selection();
            sel.ExecuteSql("select * from fournisseur");
            sel.getDr();
            if (sel.getDr().HasRows)
            {
                while (sel.getDr().Read())
                {
                    dataGridView1.Rows.Add(sel.getDr()[2].ToString(), sel.getDr()[4].ToString(), sel.getDr()[5].ToString(), sel.getDr()[6].ToString());
                }
            }
        }

sing System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Oracle.DataAccess.Client;
namespace Gestion_Budgétaire
{
    public class Connexion
    {
        protected String cs="Data source=XE;User Id=system; Password=12345;";
        protected OracleConnection conn;
        protected OracleCommand cmd;
        public void ouvrir()
        {
            try
            {
                conn = new OracleConnection();
                conn.ConnectionString = cs;
                conn.Open();
            }     
            catch (Exception ex)
            {
                MessageBox.Show("Error Fatal!" + ex.Message);
            }
        }
        public void close()
        {
            try
            {
                conn.Close();
                MessageBox.Show("disconnected");
            }
            catch (Exception ex)
            {
                MessageBox.Show("Echec!" + ex.Message);

            }
        }
    }
    public class selection 
        : Connexion
    {
        private OracleDataReader dr;
        public OracleDataReader getDr()
        {
            return dr;
        }
        public void ExecuteSql(String re)
        {
                ouvrir();
                try
                {
                    cmd = new OracleCommand();
                    cmd.Connection = conn;
                    cmd.CommandType = CommandType.Text;
                    cmd.CommandText = re;
                    dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
                
         }   
      }
    public class mettre_a_jour 
        : Connexion
    {
        public void update(String reqSql)
        {
            ouvrir();
            try
            {
                cmd = new OracleCommand();
                cmd.Connection = conn;
                cmd.CommandType = CommandType.Text;
                cmd.CommandText = reqSql;
                cmd.ExecuteNonQuery();
                MessageBox.Show("DataBase Updated");
            }
            catch(Exception ex)
            {
                MessageBox.Show("error fatal" + ex.Message);
            }
        }
    }
}