Object reference not set to an instance of an object(???)

Israel

Hi!

I am testing my code. Curiously, later after running I have this message (Object reference not set to an instance of an object) pointed on this line here:

string connStr = ConfigurationManager.AppSettings["Data Source=LUNASOFTRESEARC\\SQLEXPRESS;Initial Catalog=RentMyWrox;Integrated Security=True"].ToString();

I need your help please. Thank you!

string fileName = FileUpload1.PostedFile.FileName;

int fileLength = FileUpload1.PostedFile.ContentLength;

byte[] imageBytes = new byte[fileLength];

FileUpload1.PostedFile.InputStream.Read(imageBytes, 0, fileLength);

string connStr = ConfigurationManager.AppSettings["Data Source=LUNASOFTRESEARC\\SQLEXPRESS;Initial Catalog=RentMyWrox;Integrated Security=True"].ToString(); //Here where is the bugg

using (SqlConnection conn = new SqlConnection(connStr))

{

string sql = "INSERT INTO ImageUpload (PictureName, PictureFile) VALUES (@pictureName, @pictureFile)";

SqlParameter[] prms = new SqlParameter[2];

prms[0] = new SqlParameter("@pictureName", SqlDbType.VarChar, 50);

prms[0].Value = fileName;

prms[1] = new SqlParameter("@pictureFile", SqlDbType.Image);

prms[1].Value = imageBytes;

using (SqlCommand cmd = new SqlCommand(sql, conn))

{

cmd.Parameters.AddRange(prms);

conn.Open();

cmd.ExecuteNonQuery();

conn.Close();

}

lblMessage.Text = "Picture uploaded successsfully !";

}

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Manas Mohapatra9y ago
If below answers doesn't resolve your problem then follow below scenario that may help you:

I guess you have multiple projects in your solution like class library and console application. if your class library has app.config and contains appsetting tag. And it(app.config) needs to present in startup project also means in console application. Here we took example of windows/console application; same need to do in web application as well.

http://stackoverflow.com/questions/4330143/configurationmanager-return-null-instead-of-string-values

http://stackoverflow.com/questions/6606626/configurationmanager-appsettings-in-returning-null
0
Mangesh G9y ago
Hey Israel

string connStr = ConfigurationManager.AppSettings["Data Source=LUNASOFTRESEARC\\SQLEXPRESS;Initial Catalog=RentMyWrox;Integrated Security=True"].ToString();

Keep In mind the ConfigurationManager.AppSettings Will return null when there is No value associatd with the Key u specifying there

so as ConfigurationManager.AppSettings["Data Source=LUNASOFTRESEARC\\SQLEXPRESS;Initial Catalog=RentMyWrox;Integrated Security=True"]

is Null and You are using .ToString() Over there thats why it is giving u Object Reference
Make sure You have Proper key added at the AppSetting Here

Happy Coding :)
0
Israel9y ago
Hi Sirs,
Thank you.
Unfortunatly, I do try everything nothing change!
0
Amit Kumar Singh9y ago
hey,

let’s examine this minimal web.config with an appSetting entry to hold our connection string:

value="server=(local);database=Northwind;Integrated Security=SSPI" />

To read the key we use the ConfigurationSettings class from the System.Configuration namespace, as shown below.

private void Page_Load(object sender, EventArgs e)
{
string connectionInfo = ConfigurationSettings.AppSettings["ConnectionInfo"];
using(SqlConnection connection = new SqlConnection(connectionInfo))
{
connection.Open();

// perform work with connection

}
}
for more information refer this link
http://www.c-sharpcorner.com/uploadfile/puranindia/asp-net-web-configuration-file/
0
Manas Mohapatra9y ago
Add code in app.config/web.config
<configSections>

<appSettings>
<add key="ConStr" value="Data Source=LUNASOFTRESEARC\\SQLEXPRESS;Initial Catalog=RentMyWrox;Integrated Security=True"/>
appSettings>
Get value from config:
string connStr = ConfigurationManager.AppSettings["ConStr"].ToString();
Note: As you are using Connection String then you should use ConfigurationManager.ConnectionString..Follow link:
http://stackoverflow.com/questions/8476103/accessing-database-connection-string-using-app-config-in-c-sharp-winform
0
Rajeesh Menoth9y ago
Hi, You did wrong in this code : Please check this reference -- http://stackoverflow.com/questions/8476103/accessing-database-connection-string-using-app-config-in-c-sharp-winform
0