Re: Byte Conversion - C# Discussion Boards

24-Feb-10 23:53

Hi ppl,

I have a table with two column ID (tinyint) and TEXT (varchar). I am using this table to populate the droplist on my windows form.
when i select items from the droplist I am getting this error "ByteConverter cannot convert from System.Int32." NotSupportedException was unhandled.
I am populating the selected ID of the droplist into the main table.

Pls help.

thanks,

#realJSOP25-Feb-10 0:16

#realJSOP

25-Feb-10 0:16

show us the code that's handling the selection of the droplist item...

.45 ACP - because shooting twice is just silly
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spankyleo12325-Feb-10 0:24

25-Feb-10 0:24

combobox.datasource = data.tbtest;
combobox.DisplayMember = "Text";
comboBox.ValueMember = "ID";

This code populates the combobox droplist. and the user selects the appropriate value and the selectedvalue ID gets stored into the Form Table on Button click.

Just to add on (on Button Click)

table.TestID = Convert.ToByte(comboBox.Selectedvalue)

I hope this makes sense.

The Man from U.N.C.L.E.25-Feb-10 4:12

The Man from U.N.C.L.E.

25-Feb-10 4:12

I'm not clear why you are converting it to a byte, however ...

SelectedValue is of type Object and so you will be calling the Convert.ToByte overload that takes Object, which MUST implement IConvertible. Int32 does not implement this interface.

The solution is to force it to an int first . e.g.

table.TestID = Convert.ToByte((int)comboBox.Selectedvalue)

If you have knowledge, let others light their candles at it.
Margaret Fuller (1810 - 1850)
[My Articles] [My Website]

harold aptroot25-Feb-10 4:16

harold aptroot

25-Feb-10 4:16

Are you sure?
http://msdn.microsoft.com/en-us/library/system.int32.aspx[^]
Also, int and System.Int32 are just two different way of writing the same thing

The Man from U.N.C.L.E.25-Feb-10 8:13

The Man from U.N.C.L.E.

25-Feb-10 8:13

Thanks, I stand corrected. I checked as far as it is a structure and missed the interface declaration.

If you have knowledge, let others light their candles at it.
Margaret Fuller (1810 - 1850)
[My Articles] [My Website]

spankyleo12325-Feb-10 4:25

25-Feb-10 4:25

Sorry mate. By CType do u mean Conversion.ChangeType in C#?
Could you provide the same in C# please.

I am converting it to Byte because the column in of type tinyint (8 bit integer = 1 byte)

Thanks,

spankyleo12325-Feb-10 4:37

25-Feb-10 4:37

Thanks for the answer. When i select an item from the combobox and tab to the next control... its giving me the same exception. Do I have to change any property of the combobox?

Cheers!!

Saksida Bojan25-Feb-10 4:55

Saksida Bojan

25-Feb-10 4:55

spankyleo123 wrote:
. When i select an item from the combobox and tab to the next control... its giving me the same exception

What excepiton? Where it does happen, and in witch event?

spankyleo12325-Feb-10 4:59

25-Feb-10 4:59

Its this one ... "ByteConverter cannot convert from System.Int32." NotSupportedException was unhandled.

This happens when i select a combobox item and go to next control on the form.

Many thanks,

Winforms Listview - Looking For Decent *Free* Control

Richard MacCutchan25-Feb-10 5:15

Richard MacCutchan

25-Feb-10 5:15

This thread seems to be getting lost. Try stepping through the code in the debugger (put a breakpoint where the exception occurs), and capture all values. Then post those values, the exception, and the code around the exception, so people can see everything that is involved with the problem in one message.

txtspeak is the realm of 9 year old children, not developers. Christian Graus

#realJSOP24-Feb-10 23:27

#realJSOP

24-Feb-10 23:27

I've tried at least three free custom controls, and either they make very broad assumptions, or are so poorly designed and documented as to be unusable.

I've tried SuperList, ObjectListView, and one other that I don't recall the name of.

I need the following features (in order of importance, but first three are must-haves):

0) The ability to put one *or more* images in a given cell along with text

1) Sorting on any column

2) Supports grouping

3) Multi-line items

4) Alternate row colors

Can anyone steer me to something usable (and free)?

Re: Winforms Listview - Looking For Decent *Free* Control

Saksida Bojan25-Feb-10 0:02

Saksida Bojan

25-Feb-10 0:02

you can look at XPTable - .NET ListView meets Java's JTable[^]

If it doesn't support your cell render, you can create new render. And also the newest XPTable can be found on Here[^]

Re: Winforms Listview - Looking For Decent *Free* Control

#realJSOP25-Feb-10 0:12

#realJSOP

25-Feb-10 0:12

Wow, that looks great! I'm gonna go check it out.

C# - Fill a grid to Excelfile

Mschauder24-Feb-10 22:37

Mschauder

24-Feb-10 22:37

Hey,

I want to create a .xlsx file based on data from a grid.

My problem: I have values like 01234 (starts with zero) exporting them make 1234 Dead | X|

... so, how can I export it with right format? Confused | :confused:

I fill the file with:

if (Excelpfad == "")
    return false;

Microsoft.Office.Interop.Excel.Application excelApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
Microsoft.Office.Interop.Excel.Workbook newWorkbook = excelApp.Workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
Microsoft.Office.Interop.Excel.Sheets excelSheets = newWorkbook.Worksheets;
string currentSheet = "Tabelle1";
Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)excelSheets.get_Item(currentSheet);

for (int i = 0; i < UsingGrid.Cols; i++)
{
    for (int j = 0; j < UsingGrid.Rows; j++)
    {
        worksheet.Cells[j + 1, i + 1] = Convert.ToString(UsingGrid[j, i]);
    }
}

// Autosize cols
for (int iExcel = 0; iExcel < UsingGrid.Cols; iExcel++)
{
    ((Microsoft.Office.Interop.Excel.Range)worksheet.Columns[iExcel + 1, t]).ColumnWidth = UsingGrid.get_ColWidth(iExcel) * 0.13171875;
}

if (Excelpfad.Substring(Excelpfad.LastIndexOf(".")) == ".xls")
    worksheet.SaveAs(Excelpfad, Microsoft.Office.Interop.Excel.XlFileFormat.xlExcel8, t, t, t, t, t, t, t, t);
else if (Excelpfad.Substring(Excelpfad.LastIndexOf(".")) == ".xlsx")
    worksheet.SaveAs(Excelpfad, t, t, t, t, t, t, t, t, t);

and another question: how can I close that file correct?

I have:

newWorkbook.Close(true, n, n);
excelApp.Quit();
System.Runtime.InteropServices.Marshal.ReleaseComObject(worksheet);

but the "EXCEL.EXE" process still run

thank you

Re: C# - Fill a grid to Excelfile

Dan Mos25-Feb-10 5:48

Dan Mos

25-Feb-10 5:48

Mschauder wrote:
for (int j = 0; j < UsingGrid.Rows; j++) { worksheet.Cells[j + 1, i + 1] = Convert.ToString(UsingGrid[j, i]); } }

first question:
something like:

r.NumberFormat = "@";//where r is a Excel.Range

Note this is language specific(system language and settings).

Best way to do it is record a macro while you set the Format to text and look at the VBA produced and
translate it to C#. This silly article is especially about formatting. And the export is a lot faster than the cell by cell aproach.

Date problem

Mogamboo_Khush_Hua24-Feb-10 22:02

Mogamboo_Khush_Hua

24-Feb-10 22:02

Hi,

I am allowing user to select datetime in datetimepicker in "dd/MM/yyyy" format but when it stores in sqlserver 2005 it store as "mm/DD/yyyy", but i want it store as "dd/MM/yyyy" format in SqlServer 2005, how can i do that OR When i filter records, it should be in "dd/MM/yyyy" format ?

Regards,
XYZ

AspDotNetDev24-Feb-10 22:14

AspDotNetDev

24-Feb-10 22:14

The internal format used to store a date time has nothing to do with how it is serialized as a string. Both SQL and C# have techniques for serializing date/times. In particular, you'll want to look into DATEPART and CONVERT for SQL and ToString and String.Format for C#. The C# DateTime also has several methods that allow you to serialize to different common formats.

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Chetan Patel24-Feb-10 22:41

Chetan Patel

24-Feb-10 22:41

Write in SQL Select Query

Select Convert(varchar(10),getdate(),103) Like this will return dd-MM-yyyy

And in C# use .ToString("dd-MM-yyyy");

In grid use DataFormatString Property and make sure HTMLEncode="False" set in That column

Best Regards,
Chetan Patel

AspDotNetDev24-Feb-10 22:57

AspDotNetDev

24-Feb-10 22:57

I already know how to do that... you might want to reply to the OP to tell him/her what you've told me. Though, to be honest, I think I gave him/her enough information already.

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