Need help converting from VB to C#[Answered] RSS

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Last post Jan 16, 2020 04:00 PM by Rakib1

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Rakib1

Member

23 Points

78 Posts

Need help converting from VB to C#

Jan 14, 2020 10:03 PM|Rakib1|LINK

Hi,

i need help on below code to convert into C# from visual Basic. all i am trying to check the datatable and apply the substrings to get the daynum, mth but problem is dont know how to fit substring into below code because Mid function not work in C#. how to apply substring into below code?

If Not IsDBNull(dr("maint_end_date")) And Len(dr("maint_end_date")) > 1 Then
                        daynum = Mid(dr("maint_end_date").ToString, 1, 2)
                        mth = Mid(dr("maint_end_date").ToString, 4, 3)
                        If mth = "FEB" And daynum = 29 Then
                            mntenddt = "'01-MAR-" & Ddl_newyears.SelectedItem.Value & "'"
                        Else
                            mntenddt = "'" & dr("maint_end_date").ToString.Replace(Ddl_oldyears.SelectedItem.Value, Ddl_newyears.SelectedItem.Value) & "'"
                        End If
                    Else
                        mntenddt = "null"
                    End If

- Reply
Rion William...
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Re: Need help converting from VB to C#

Jan 14, 2020 10:29 PM|Rion Williams|LINK
The Substring() method is the C# equivalent of Mid from Visual Basic, so you can use them interchangeably:
```
// Visual Basic
daynum = Mid(dr("maint_end_date").ToString, 1, 2)

// C#
daynum = dr("maint_end_date").ToString().Substring(1, 2);
```
However, it looks like you are parsing dates here. If that's the case, you may want to consider using the DateTime.ParseExact() method which will allow you to define a formatting string and convert it into a DateTime object that will allow you to access things like DayOfWeek, Day, Month, Year, etc.

You might consider sharing what your dates look like, as it might be as simple as:
```
// Get your date string
var dateString = dr["maint_end_date"].ToString();

// Parse it into a date (example for something like "mon-01-2020", etc.)
var date = DateTime.ParseExact(dateString, "ddd-MM-yyyy", null);
```
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Rakib1

Member

23 Points

78 Posts

Re: Need help converting from VB to C#

Jan 14, 2020 10:51 PM|Rakib1|LINK

Still getting error. could you please convert whole code into C#? i did most of the part already but getting error.

Thanks for your help.

DataTable ds = DatabaseConnections.GetDataTable(query);

                foreach (DataRow dr in ds.Rows)
                {
                    if (dr.Table.Columns.Contains("item_description"))
                        item_descr = "" + dr["item_description"].ToString() + "";
                    else
                        item_descr = "null";

                    if (dr.Table.Columns.Contains("vendor_id"))
                        vendor_id = dr["vendor_id"].ToString();
                    else
                        vendor_id = "null";
                    if (dr.Table.Columns.Contains("estimated_amount"))
                        estamt = dr["estimated_amount"].ToString();
                    else
                        estamt = "null";
                    if (dr.Table.Columns.Contains("renewal_type"))
                        renewtyp = "'" + dr["renewal_type"].ToString() + "'";
                    else
                        renewtyp = "null";


                    if (dr.Table.Columns.Contains("maint_end_date"))
                    {   
                        daynum =  dr("maint_end_date").ToString.Substring(0, 2);
                        mth = dr("maint_end_date").ToString.Substring(3, 3);

                        if
                                 (mth = "FEB" && daynum = 29)
                            mntenddt = "\'01-MAR-" + (ddlNewYear.SelectedItem.Value + "\'");

                        else

                            mntenddt = ("\'" + (dr["maint_end_date"].ToString().Replace(ddlOldYear.SelectedItem.Value, ddlNewYear.SelectedItem.Value) + "\'"));


                    }
                    else
                        mntenddt = "null";

- Reply
KathyW
Contributor

5961 Points

2466 Posts

Re: Need help converting from VB to C#

Jan 15, 2020 12:27 AM|KathyW|LINK

Since your code is incomplete (for example you haven't defined item_descr or vendor_id, and so on, anywhere in the code you show, although you have assigned values to them), it would be more useful if you told us what errors you were getting, on which line. Or show us all the code, including where everything is defined.
- Reply
samwu
Contributor

3370 Points

1409 Posts

Re: Need help converting from VB to C#

Jan 15, 2020 02:16 AM|samwu|LINK

Hi Rakib1,

Rakib1
Still getting error. could you please convert whole code into C#? i did most of the part already but getting error.

Since your code is incomplete, I am not sure where your errors are.

But if you want to convert VB into C# code. you can use this tool: http://converter.telerik.com/

If you still have questions, please post your complete code.

Best regards,

Sam

.NET forums are moving to a new home on Microsoft Q&A, we encourage you to go to Microsoft Q&A for .NET for posting new questions and get involved today.

Rakib1

Member

23 Points

78 Posts

Re: Need help converting from VB to C#

Jan 15, 2020 03:42 PM|Rakib1|LINK

Thanks for your reply. Below is the convert code from VB to C#. if you notice in the code with color having issue. may be just we need tweak here few attributes. any question please let me know.

using System;
using System.Web.UI;
using System.Data.SqlClient;
using System.Data.OleDb;
using System.Data;
using System.Web.UI.WebControls;
using System.Collections;

public partial class CopyData : System.Web.UI.Page
{
    private int reccount;

    protected void Page_Load(object sender, System.EventArgs e)
    {
        string query;
        if (!IsPostBack)
        {
            query = "select max(to_char(maint_end_date,'yyyy')) maxyr from  T_HDC_MAINTENANCE_SCHEDULE3 ";
            query = query + " where maint_end_date is not null ";
            PopulateOldYearDropdownList();
            PopulateNewYearDropdownList();

        }
    }
    protected void PopulateOldYearDropdownList()
    {
        MaintenanceOldYearDropDownList OldYear = new MaintenanceOldYearDropDownList(
            ddlOldYear,
            "select distinct to_char(maint_end_date, 'yyyy') years from  T_HDC_MAINTENANCE_SCHEDULE3 where maint_end_date is not null order by years ",
            "years",
            "years");
        OldYear.PopulateDropDownList();
        OldYear.InsertItemIntoDropDownList("", "0", 0);
    }
    public void PopulateNewYearDropdownList()
    {
        int yearval = 2019;
        ArrayList YearValues = new ArrayList();

        for (var i = 0; i <= 10; i++)
        {
            yearval = yearval + 1;
            YearValues.Add(yearval);
        }

        // assign year values to the drop down list of year
        ddlNewYear.Items.Clear();
        ddlNewYear.DataSource = YearValues;
        ddlNewYear.DataBind();
    }   

    protected void btnBack_Click(object sender, EventArgs e)
    {
        Response.Redirect("Home.aspx");
    }

    protected void btnCopy_Click(object sender, EventArgs e)
    {
        string alert, query, dowk, mth, oldmntdt;
        bool fnd = false;
        int reccount, daynum, yr, lpyr;
        // DataSet ds;
        string item_descr, vendor_id, estamt, renewtyp, mntenddt, actamt, ponum, contact, stat, stat_dt;
        string create_dt, update_dt, contact_email;
        //Lblexception.Text = " ";
        try
        {

            // check if records already exist for new year
            query = "select count(to_char(maint_end_date,'yyyy')) cnt" + " from  T_HDC_MAINTENANCE_SCHEDULE3 " + " where maint_end_date is not null " + " and to_char(maint_end_date,'yyyy') = " + ddlNewYear.SelectedItem.Text;
            reccount = ExecuteScalarCommand(query);

            if (reccount > 0)
            {
                alert = "<script language='javascript'>" + "alert ('Records already exist for this calendar year. Select another value for the new year'); " + "</script>";
                ClientScript.RegisterStartupScript(typeof(Page), "ClientScript", alert);
            }
            else
            {
                // retieve records for the selected year
                query = "select item_description, vendor_id, estimated_amount, renewal_type,  " + " to_char(maint_end_date,'dd-MON-YYYY') maint_end_date, actual_amount, po_number, contact_person, " + " status, to_char(status_date,'dd-MON-YYYY') status_date, contact_email, " + " to_char(creation_date,'dd-MON-YYYY') creation_date, " + " to_char(last_update_date,'dd-MON-YYYY') last_update_date " + " from T_HDC_MAINTENANCE_SCHEDULE3 " + " where maint_end_date is not null " + " and to_char(maint_end_date,'yyyy') = " + ddlOldYear.SelectedItem.Text;               

                DataTable ds = DatabaseConnections.GetDataTable(query);

                foreach (DataRow dr in ds.Rows)
                {
                    if (dr.Table.Columns.Contains("item_description"))
                        item_descr = "" + dr["item_description"].ToString() + "";
                    else
                        item_descr = "null";

                    if (dr.Table.Columns.Contains("vendor_id"))
                        vendor_id = dr["vendor_id"].ToString();
                    else
                        vendor_id = "null";
                    if (dr.Table.Columns.Contains("estimated_amount"))
                        estamt = dr["estimated_amount"].ToString();
                    else
                        estamt = "null";
                    if (dr.Table.Columns.Contains("renewal_type"))
                        renewtyp = "'" + dr["renewal_type"].ToString() + "'";
                    else
                        renewtyp = "null";

                    if (!Information.IsDBNull(dr("maint_end_date")) & Strings.Len(dr("maint_end_date")) > 1)
                    {
                        daynum = Strings.Mid(dr("maint_end_date").ToString(), 1, 2);
                        mth = Strings.Mid(dr("maint_end_date").ToString(), 4, 3);
                        if (mth == "FEB" & daynum == 29)
                            mntenddt = "'01-MAR-" + Ddl_newyears.SelectedItem.Value + "'";
                        else
                            mntenddt = "'" + dr("maint_end_date").ToString().Replace(Ddl_oldyears.SelectedItem.Value, Ddl_newyears.SelectedItem.Value) + "'";
                    }
                    else
                        mntenddt = "null";
                   
                    if (dr.Table.Columns.Contains("actual_amount"))
                        actamt = dr["actual_amount"].ToString();
                    else
                        actamt = "null";
                    if (dr.Table.Columns.Contains("po_number"))
                        ponum = dr["po_number"].ToString();
                    else
                        ponum = "null";
                    if (dr.Table.Columns.Contains("contact_person"))
                        contact = "'" + dr["contact_person"].ToString() + "'";
                    else
                        contact = "null";
                    if (dr.Table.Columns.Contains("contact_email"))
                        contact_email = "'" + dr["contact_email"].ToString() + "'";
                    else
                        contact_email = "null";
                    if (dr.Table.Columns.Contains("status"))
                        stat = "'" + dr["status"].ToString() + "'";
                    else
                        stat = "null";
                    if (dr.Table.Columns.Contains("status_date"))
                        stat_dt = "'" + dr["status_date"].ToString() + "'";
                    else
                        stat_dt = "null";
                    if (dr.Table.Columns.Contains("creation_date"))
                        create_dt = "'" + dr["creation_date"].ToString() + "'";
                    else
                        create_dt = "null";
                    if (dr.Table.Columns.Contains("last_update_date"))
                        update_dt = "'" + dr["last_update_date"].ToString() + "'";
                    else
                        update_dt = "null";
                    query = "insert into t_hdc_maintenance_schedule3 (item_description, vendor_id, estimated_amount, renewal_type,";
                    query = query + "maint_end_date, actual_amount, po_number, contact_person, contact_email,";
                    query = query + "status, status_date,last_update_date,creation_date)";
                    query = query + " VALUES ( '" + item_descr + "'," + vendor_id + "," + estamt + "," + renewtyp;
                    query = query + "," + mntenddt + "," + actamt + ",null," + contact + "," + contact_email;
                    query = query + ",null,null,sysdate,sysdate)";

                    DatabaseConnections.ExecuteScalarCommand(query);
                }

                // retrieve newly inserted records
                query = "select to_char(maint_end_date, 'dd-MON-yyyy' ) maint_end_date,to_char(maint_end_date, 'DY-yyyy' ) daystr, " + " to_char(maint_end_date, 'dd-mm-yyyy' ) dayval " + " from T_HDC_MAINTENANCE_SCHEDULE3 " + " where maint_end_date is not null " + " and to_char(maint_end_date,'yyyy') = " + ddlNewYear.SelectedItem.Value;
                DatabaseConnections.ExecuteScalarCommand(query);

                foreach (DataRow dr in ds.Rows)
                {
                    if (!Information.IsDBNull(dr("maint_end_date")))
                    {
                        daynum = Strings.Mid(dr("maint_end_date").ToString(), 1, 2);
                        mth = Strings.Mid(dr("maint_end_date").ToString(), 4, 3);
                        yr = Strings.Mid(dr("maint_end_date").ToString(), 8);
                        oldmntdt = "'" + dr("maint_end_date") + "'";
                    }
                    if (!Information.IsDBNull(dr("daystr")))
                        dowk = Strings.Mid(dr("daystr").ToString(), 1, 3);
                    if (dowk == "SAT")
                        daynum = daynum + 2;
                    if (dowk == "SUN")
                        daynum = daynum + 1;
                    // adjust day number if more than 30 days
                    if ((mth == "APR" | mth == "JUN" | mth == "SEP" | mth == "NOV") & daynum > 30)
                    {
                        daynum = daynum - 30;
                        if (mth == "APR")
                            mth = "MAY";
                        if (mth == "JUN")
                            mth = "JUL";
                        if (mth == "SEP")
                            mth = "OCT";
                        if (mth == "NOV")
                            mth = "DEC";
                    }
                    else if (daynum > 31)
                    {
                        daynum = daynum - 31;
                        switch (mth)
                        {
                            case "JAN":
                                {
                                    mth = "FEB";
                                    break;
                                }

                            case "MAR":
                                {
                                    mth = "APR";
                                    break;
                                }

                            case "MAY":
                                {
                                    mth = "JUN";
                                    break;
                                }

                            case "JUL":
                                {
                                    mth = "AUG";
                                    break;
                                }

                            case "AUG":
                                {
                                    mth = "SEP";
                                    break;
                                }

                            case "OCT":
                                {
                                    mth = "NOV";
                                    break;
                                }

                            case "DEC":
                                {
                                    mth = "JAN";
                                    yr = yr + 1;
                                    break;
                                }

                            default:
                                {
                                    break;
                                }
                        }
                    }
                    lpyr = yr % 4;
                    // adjust day number for Feb
                    if (mth == "FEB" & daynum > 28)
                    {
                        daynum = daynum - 28;
                        mth = "MAR";
                    }
                    mntenddt = daynum.ToString() + "-" + mth + "-" + yr.ToString();
                    query = "update T_HDC_MAINTENANCE_SCHEDULE3 set maint_end_date = '" + mntenddt + "' where maint_end_date = " + oldmntdt;

                    DatabaseConnections.ExecuteScalarCommand(query);
                }

                if (ds == null)
                {
                }
            }
            //Lblexception.Text = "* Records were copied successfully.";
        }
        catch (Exception ex)
        {
        }
    }

    private int ExecuteScalarCommand(string query)
    {
        DatabaseConnections.ExecuteScalarCommand(query);
        return reccount;
    }
}

- Reply
KathyW
Contributor

5961 Points

2466 Posts
Re: Need help converting from VB to C#

Jan 15, 2020 08:40 PM|KathyW|LINK
"if you notice in the code with color having issue"

What issues? In Visual Studio, if there is a problem with code that can be determined before running it, VS will underline the problem areas with a squggly red line. Hover your mouse over the underlined item and it will tell you the error.

What errors are you getting?

If we put your code in VS, we'll get errors simply because we don't have your .aspx page, and references to controls on the page, such as MaintenanceOldYearDropDownList, will not be understood.

Trying to ignore errors that are likely controls on your page, I also get errors for DatabaseConnections, Information, and Strings (which are not defined anywhere in the .cs or .aspx file). Also, GetDataTable(query) is not defined anywhere.

For the case of Strings, the problem is that you are using Strings.Mid which is VB, not C#. Rion's first post showed you how to use C#'s substring method instead.

There are also several places where you are doing a compare with a variable that has been defined as a string (good), but not initialized before the comparison (bad: you can't compare something to nothing). Either initialize them with a default value, or only do the comparison inside an "if" statement that sucessfully found a value for them, not in both cases where they may have a value and may not have a value.

Two examples:
```
if ((mth == "APR" | mth == "JUN" | mth == "SEP" | mth == "NOV") & daynum > 30)
                    {
                        daynum = daynum - 30;
                        if (mth == "APR")
                            mth = "MAY";
                        if (mth == "JUN")
                            mth = "JUL";
                        if (mth == "SEP")
                            mth = "OCT";
                        if (mth == "NOV")
                            mth = "DEC";
                    }
```
You don't always assign a value to mth, so you could be comparing nothing. The assignment of mth shows three problems:
```
 if (!Information.IsDBNull(dr("maint_end_date")) & Strings.Len(dr("maint_end_date")) > 1)
                    {
                        daynum = Strings.Mid(dr("maint_end_date").ToString(), 1, 2);
                        mth = Strings.Mid(dr("maint_end_date").ToString(), 4, 3);
                        if (mth == "FEB" & daynum == 29)
                            mntenddt = "'01-MAR-" + Ddl_newyears.SelectedItem.Value + "'";
                        else
                            mntenddt = "'" + dr("maint_end_date").ToString().Replace(Ddl_oldyears.SelectedItem.Value, Ddl_newyears.SelectedItem.Value) + "'";
                    }
                    else
                        mntenddt = "null";
```
The "else" doesn't assign anything to mth, so it is possible for it to not have a value. That causes the problem in the first section. When mth is assigned, it is based on the undefined "Information" and the VB Strings.Mid, so it won't work anyway.

In the code you copied from, where do they define DatabaseConnections, GetDataTable(query), and Information?

samwu

Contributor

3370 Points

1409 Posts

Re: Need help converting from VB to C#

Jan 16, 2020 08:34 AM|samwu|LINK

Hi Rakib1,

Rakib1

if (!Information.IsDBNull(dr("maint_end_date")) & Strings.Len(dr("maint_end_date")) > 1)
                    {
                        daynum = Strings.Mid(dr("maint_end_date").ToString(), 1, 2);
                        mth = Strings.Mid(dr("maint_end_date").ToString(), 4, 3);
                        if (mth == "FEB" & daynum == 29)
                            mntenddt = "'01-MAR-" + Ddl_newyears.SelectedItem.Value + "'";
                        else
                            mntenddt = "'" + dr("maint_end_date").ToString().Replace(Ddl_oldyears.SelectedItem.Value, Ddl_newyears.SelectedItem.Value) + "'";
                    }
                    else
                        mntenddt = "null";

In your code, there are some VB methods, you need to replace it with C # method. such as Information.IsDBNull(), Strings.Len(), Strings.Mid(). etc.

if (dr["maint_end_date"] != DBNull.Value & dr["maint_end_date"].ToString().Length > 1)
                {
                    daynum = dr["maint_end_date"].ToString().Substring(1, 2);

                    mth = dr["maint_end_date"].ToString().Substring(4, 3);
                    if (mth == "FEB" & daynum == 29)
                        mntenddt = "'01-MAR-" + Ddl_newyears.SelectedItem.Value + "'";
                    else
                        mntenddt = "'" + dr["maint_end_date"].ToString().Replace(Ddl_oldyears.SelectedItem.Value, Ddl_newyears.SelectedItem.Value) + "'";
                }

If you have any questions please let me know.

Best regards,

Sam

.NET forums are moving to a new home on Microsoft Q&A, we encourage you to go to Microsoft Q&A for .NET for posting new questions and get involved today.

- Reply
Rakib1
Member

23 Points

78 Posts

Re: Need help converting from VB to C#

Jan 16, 2020 04:00 PM|Rakib1|LINK

Thanks for your help Samwu. it helps to resolve my problem.

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