命名空间中不存在类型或命名空间名称（您是否缺少程序集引用？）

Question

I know that this question has been already asked, but I cannot find anything that can help solve my problem.

I want to connect my aspx page ( Retete.aspx ) to a Microsoft SQL database. I'm getting this error on Retete.aspx.cs :

Error 1 The type or namespace name 'GlobalClass' does not exist in the namespace 'ProiectSera' (are you missing an assembly reference?) The error points to this line of code:

ProiectSera.GlobalClass.Update(ValRefTempSol.Text, ValRefTempAer.Text);

Where ProiectSera is the project name, GlobalClass is the file where I make the operation on the db.

My using statements are:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using ProiectSera;

The Target Framework is set to .net-4.5 .

What should I do to solve this error?

Update My GlobalClass.cs is:

using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using System.IO;
using ProiectSera;

using System.Data.Services;

namespace ProiectSera.App_Code
{
    public static class GlobalClass
    {
        static public void Update(string _param1, string _param2)
        {//function to update}
}
}

App_Code is a folder where GlobalClass.cs is. I tried and

ProiectSera.App_Code.GlobalClass.Update(ValRefTempSol.Text, ValRefTempAer.Text); //

but I had the same error. And I put the GlobalClass.cs in the project's root. I also removed the .App_Code from namespace ProiectSera.App_Code

UPDATE1 My Retete.aspx.cs is

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using ProiectSera;
using ProiectSera.App_Code;

namespace ProiectSera
{
    public partial class Retete : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void btnSave_Click(object sender, EventArgs e)
        {
            string intValRefTempSol;
            string intValRefTempAer;

 //           intValRefTempSol = ValRefTempSol.Text;
 //           intValRefTempAer = ValRefTempAer.Text;


   //         ProiectSera.App_Code.GlobalClass.Update(ValRefTempSol.Text, ValRefTempAer.Text);
            GlobalClass.Update(ValRefTempSol.Text, ValRefTempAer.Text);
}
}
}

Answer 1

Your GlobalClass is in the namespace ProiectSera.App_Code .

So the class name is ProiectSera.App_Code.GlobalClass

Make sure you don't have a ProiectSera class in the ProiectSera namespace also, otherwise if declaring using ProiectSera on top, it'll try to use it (as a general rule, don't name any class the same as your namespace).

If that still doesn't work, you may want to try using the global namespace:

global::ProiectSera.GlobalClass.Update(ValRefTempSol.Text, ValRefTempAer.Text);

and see if that works: if it doesn't, and GlobalClass is in the same project, then there's something else you haven't shown us

Update

The only other thing that comes to mind, if you are positive that both files are on the same project/assembly, is that GlobalClass.cs is not being actually compiled. Make sure the Build Action is set to Compile (you can see the build action right clicking on the GlobalClass.cs in the solution explorer and selecting Properties ).

Answer 2

If you are using VS.NET:

1. Right click on the References folder on your project.
2. Select Add Reference.
3. Select the .NET tab (or select the Browse button if it is not a .NET Framework assembly).
4. Double-click the assembly containing the namespace in the error message.
5. Press the OK button.

Answer 3

Ensure the following...

• That you have a project reference to ProiectSera from your web application, if it's in a separate library. If GlobalClass is in the web application project itself, you won't require this, but if GlobalClass is defined in a separate library in the same solution or elsewhere, then you're going to need to add a reference to that external library in your web application.
• Ensure that ProiectSera should not be ProjectSera (if it's a typo).
• Ensure that you have your ProiectSera using statement in place at the top ( using ProiectSera; ). Assuming that this is the correct namespace. Check the namespace of your GlobalClass class and use that using accordingly in the class that wishes to use its functionality.

• Then, simply call this in your code, assuming that Update is a static method of GlobalClass.

  GlobalClass.Update(ValRefTempSol.Text, ValRefTempAer.Text);

EDIT: given that you've now posted your GlobalClass code, you can see that the namespace for this class is ProiectSera.App_Code ;. So you need to have that as your using statement in the other class using ProiectSera.App_Code; . And then call it via simply GlobalClass.Update, as mentioned above.

If you don't understand how namespacing works in C#, then I recommend you check this out ( https://msdn.microsoft.com/en-us/library/dfb3cx8s.aspx ).