C# error Not all Code paths return a value, when doing just the quesry returns value just fine

Question

I need to fill a datagrid With the information from the db, i have a dataAccess class and the normal form.cs file.When i do the query itself it returns value just fine but for some reason it doesen´t when run in code trough the sp. I´ve gotten this error in WindowsForms that i don´t quite understand what i did wrong. I´ll start by showing my dataAccess class

    public DataTable Sp_Teste()
    {

        try
        {
            ManageConnectionStateIbml1();
            SqlCommand command = new SqlCommand("SP_SELECT_DOCS_WHERE_JOBID_STATUS", 
            connectionIBML1);
            command.CommandType = CommandType.StoredProcedure;
            SqlDataAdapter adapter = new SqlDataAdapter(command);
            DataSet ds = new DataSet();
            adapter.Fill(ds);
            return ds.Tables[0];


        }
        catch (Exception ex)
        {
            Console.WriteLine("Erro: " + ex.Message);
        }
        finally
        {
            ManageConnectionStateIbml1();
            connectionIBML1.Close();
           
        }
       

    }

Next There is my Form.cs, since i have 3 datagridviews i seperated them with regions.

        #region DatagridViewDocumentos
        dataGridViewDocumentos.DataSource = null;
        dataGridViewDocumentos.Columns.Clear();
        dataGridViewDocumentos.Refresh();
        DataTable dt = da.Sp_Teste();
        dataGridViewDocumentos.DataSource = dt;
        dataGridViewDocumentos.ColumnCount = 4;
        DataGridViewColumn columnCaixa = dataGridViewDocumentos.Columns[0];
        columnCaixa.Width = 50;
        DataGridViewColumn columnDOC = dataGridViewDocumentos.Columns[1];
        columnDOC.Width = 50;
        DataGridViewColumn columnID = dataGridViewDocumentos.Columns[2];
        columnID.Width = 50;
        DataGridViewColumn columnPROC = dataGridViewDocumentos.Columns[3];
        columnPROC.Width = 50;
        dataGridViewDocumentos.Columns[0].Name = "Caixa";
        dataGridViewDocumentos.Columns[1].Name = "DOC";
        dataGridViewDocumentos.Columns[2].Name = "ID";
        dataGridViewDocumentos.Columns[3].Name = "Proc";

       
        #endregion

Hope someone can point out my mistake, thanks.

Ask yourself, what would happen when an exception occurs? What is the return value then? — Hans Keﬆing, Feb 15 '21 at 10:27
@HansKeﬆing ok so i just realized my mistake, there are two to be exact will post a answer in the next 10 min. — Tiago Silva, Feb 15 '21 at 10:41
Updating the question since i fixed the other problem but now i have another one. — Tiago Silva, Feb 15 '21 at 10:57
Please don't edit a question so as to *invalidate* existing answers. You asked a question, you got answers. If you have a further question, please ask a *separate* question. — Damien_The_Unbeliever, Feb 15 '21 at 11:10
Did you debug this? What are the values of JobID and BatchID? When you call that stored proc directly on the database with those values, does it return results (as first or only table)? — Hans Keﬆing, Feb 15 '21 at 11:10
@Damien_The_Unbeliever i completed the question with the answer as well, and since its apart of the same problem i thought there wasen´t a problem with it — Tiago Silva, Feb 15 '21 at 11:11
@HansKeﬆing when i run the sp on itself it returns those values — Tiago Silva, Feb 15 '21 at 11:11

score 1 · Answer 1 · answered Feb 15 '21 at 10:37

1

Add Return Statement at the end of the function.

finally
{
    ManageConnectionStateIbml1();
    connectionIBML1.Close(); 
}

return null;

answered Feb 15 '21 at 10:37

Muhammad Usama Alam

209
4
13

2

Or better in almost all cases: don't swallow exceptions... – Jon Skeet Feb 15 '21 at 10:45
Updating the question since i fixed the other problem but now i have another one. – Tiago Silva Feb 15 '21 at 10:57

score 1 · Accepted Answer · answered Feb 15 '21 at 10:47

public DataTable Sp_Teste()
{
    DataTable results = null;
    try
    {
        ManageConnectionStateIbml1();
        SqlCommand command = new SqlCommand("SP_SELECT_DOCS_WHERE_JOBID_STATUS", 
        connectionIBML1);
        command.CommandType = CommandType.StoredProcedure;
        SqlDataAdapter adapter = new SqlDataAdapter(command);
        DataSet ds = new DataSet();
        adapter.Fill(ds);
        results = ds.Tables[0];


    }
    catch (Exception ex)
    {
       Console.WriteLine("Erro: " + ex.Message);
    }
    finally
    {
        ManageConnectionStateIbml1();
        connectionIBML1.Close();
       
    }
    return results;
}

As noted on the other answer: I'd almost always recommend not swallowing the exception, instead of returning null. — Jon Skeet, Feb 15 '21 at 10:49
Updating the question since i fixed the other problem but now i have another one. — Tiago Silva, Feb 15 '21 at 10:57

score 1 · Answer 3 · answered Feb 15 '21 at 11:13

1

I think you just need to call DataBind() method of the gridview after assigning the data to its dataSource property.

#region DatagridViewDocumentos
    dataGridViewDocumentos.DataSource = null;
    dataGridViewDocumentos.DataBind();
    dataGridViewDocumentos.Columns.Clear();
    dataGridViewDocumentos.Refresh();
    DataTable dt = da.Sp_Teste();
    dataGridViewDocumentos.DataSource = dt;
    dataGridViewDocumentos.DataBind();
    dataGridViewDocumentos.ColumnCount = 4;
    DataGridViewColumn columnCaixa = dataGridViewDocumentos.Columns[0];
    columnCaixa.Width = 50;
    DataGridViewColumn columnDOC = dataGridViewDocumentos.Columns[1];
    columnDOC.Width = 50;
    DataGridViewColumn columnID = dataGridViewDocumentos.Columns[2];
    columnID.Width = 50;
    DataGridViewColumn columnPROC = dataGridViewDocumentos.Columns[3];
    columnPROC.Width = 50;
    dataGridViewDocumentos.Columns[0].Name = "Caixa";
    dataGridViewDocumentos.Columns[1].Name = "DOC";
    dataGridViewDocumentos.Columns[2].Name = "ID";
    dataGridViewDocumentos.Columns[3].Name = "Proc";

   
    #endregion

answered Feb 15 '21 at 11:13

brucode Technology

152
5

Hello i tried it out it doens´t let me do that – Tiago Silva Feb 15 '21 at 11:15
it says datagridview does not contain a definition for databind and no accessible extension method datavind accepting a first argument of type datagridview could be found (are you missing a using directive or an accembly reference?) – Tiago Silva Feb 15 '21 at 11:19
sorry my bad,, i forgot that you are working with windowforms,,, – brucode Technology Feb 15 '21 at 11:24
I think,, You should bind data after setting up the columns part – brucode Technology Feb 15 '21 at 11:25
will do then, ill try it out – Tiago Silva Feb 15 '21 at 11:27
i have posted another answer ,, which will give you a idea how you can achieve this.. – brucode Technology Feb 15 '21 at 11:33
Checking it out now – Tiago Silva Feb 15 '21 at 11:52

score 1 · Answer 4 · answered Feb 15 '21 at 11:32

1

As you are clearing the columns and then binding the data, So i think this is creating the issue,, Just think after removing all the columns from grid,, how you can access them,, OS firstly set up the columns then bind the data.

#region DatagridViewDocumentos
    dataGridViewDocumentos.DataSource = null;
    dataGridViewDocumentos.Columns.Clear();
    dataGridViewDocumentos.Refresh();

    DataGridViewColumn columnCaixa = new DataGridViewColumn("Caixa");
    columnCaixa.Width = 50;
    DataGridViewColumn columnDOC = new DataGridViewColumn("DOC");
    columnDOC.Width = 50;
    DataGridViewColumn columnID = new DataGridViewColumn("ID");
    columnID.Width = 50;
    DataGridViewColumn columnPROC = new DataGridViewColumn("Proc");
    columnPROC.Width = 50;

    dataGridViewDocumentos.columns.Add(columnCaixa);
    dataGridViewDocumentos.columns.Add(columnDOC );
    dataGridViewDocumentos.columns.Add(columnID );
    dataGridViewDocumentos.columns.Add(columnPROC );
    dataGridViewDocumentos.ColumnCount = 4;

    DataTable dt = da.Sp_Teste();
    dataGridViewDocumentos.DataSource = dt;
    #endregion

answered Feb 15 '21 at 11:32

brucode Technology

152
5

Thank you for the help, i did what you did and im trying to do datagridviewDocuments dataBind and it doesen´t exist, is it dataBindingComplete or DataBindings? – Tiago Silva Feb 15 '21 at 11:56
WindowForms does not require DataBind() method for the databinding – brucode Technology Feb 15 '21 at 11:57
ah ok, then i dont know what to do next – Tiago Silva Feb 15 '21 at 11:58
can you post your latest code ? .. What is the problem now – brucode Technology Feb 15 '21 at 11:59
i can i will make a new question is that ok? – Tiago Silva Feb 15 '21 at 12:00
Sure. It will be ok – brucode Technology Feb 15 '21 at 12:02
here is the link to the new question, https://stackoverflow.com/questions/66207758/datagridview-not-showing-the-information – Tiago Silva Feb 15 '21 at 12:07

C# error Not all Code paths return a value, when doing just the quesry returns value just fine

4 Answers4