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Object reference not set to an instance of an object. - App.config

I get an error, and in the local window, I see null for both conSettings and connectionString. I have the right to say that the ConfigurationManager is null and I need to create a new object. Maybe I'm using Access and maybe something was missing in the App.config file. Can someone help me in solving this problem please. Thanks in advance.

App.config File ...

   <?xml version="1.0" encoding="utf-8" ?>
    <configuration>
    <appSettings>
       <add key="MyDBConnectionString" value="Provider=Microsoft.Jet.OLEDB.4.0;Data 
                   Source=E:\...\Database1.mdb"/>
    </appSettings>
    </configuration>

File Form.cs ...

 private void btnShow_Click(object sender, EventArgs e)
    {
        ConnectionStringSettings conSettings = ConfigurationManager.ConnectionStrings["MyDBConnectionString"];

        string connectionString = ConfigurationManager.ConnectionStrings["MyDBConnectionString"].ConnectionString; // error points here

        try
        {
            con = new OleDbConnection(connectionString);
            con.Open();
            cmd = new OleDbCommand("SELECT * FROM Table1", con);
            objReader = cmd.ExecuteReader();
            while (objReader.Read())
            {
                txtID.Text = ds.Tables[0].Rows[rno][0].ToString();
                CBAgeGroup.Text = ds.Tables[0].Rows[rno][1].ToString();
                CBGender.Text = ds.Tables[0].Rows[rno][2].ToString();
                CBCrimOffen.Text = ds.Tables[0].Rows[rno][3].ToString();
                if (ds.Tables[0].Rows[rno][4] != System.DBNull.Value)
                {
                    photo_aray = (byte[])ds.Tables[0].Rows[rno][4];
                    MemoryStream ms = new MemoryStream(photo_aray);
                   pictureBox1.Image = Image.FromStream(ms);
                }
                txtCV.Text = ds.Tables[0].Rows[rno][5].ToString();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
        finally
        {
            con.Close();
        }
    }

I was recommended to use App.config.

VS 2010 C # MS Access 2003

UPDATE 1 Now my App.config looks like this ...

<configuration>
    <ConnectionString>
        <add key="MyDBConnectionString"   value="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Raj\Education\C_Sharp\Test1\Database1.mdb"/>
    </ConnectionString>

Now I get the error ... "Failed to initialize the configuration system." I look at it now on Google.

Update 2 Tried ...

<configuration>
 <connectionStrings>
<add name="MyDBConnectionString" connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data   
        Source=E:\...\Database1.mdb"/>
  </connectionStrings>
 </configuration>

" , "

3

<configuration>
<connectionStrings>
    <clear />
    <add name="MyDBConnectionString"
     providerName="System.Data.OleDb" connectionString="Provider=Microsoft.Jet.OLEDB.4.0; Source=\Database1.mdb" />
</connectionStrings>

3 . . , System.Configuration;

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+5
5

AppSettings, ,

string connectionString = 
      ConfigurationSettings.AppSettings["MyDBConnectionString"];

,

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, , connectionStrings app config

  string connectionString = 
      ConfigurationManager.ConnectionStrings["MyDBConnectionString"].ConnectionString; // error points here


<?xml version="1.0"?>
<configuration>
  <connectionStrings>
    <add name="MyDBConnectionString" 
    connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data 
               Source=E:\...\Database1.mdb"/>
  </connectionStrings>
</configuration>
+9

, app.config . app.config , .

+5

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string connectionString = ConfigurationManager.ConnectionStrings["MyDBConnectionString"].ConnectionString;

- .

ConfigurationManager.ConnectionStrings, , App.Config appSettings, , ConnectionStrings

ConnectionStrings app.config( ConfigurationManager.ConnectionStrings) appSettings.

:

http://msdn.microsoft.com/en-us/library/ms254494(v=vs.80).aspx

MSDN .

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