Object cannot be cast from DBNull to other types error shown?

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Hi,
My code is this i dono what's my error, Please help me.

C#

decimal getTotalValue(GridView view, int listSourceRowIndex)
    {
        decimal unitPrice = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "Each"));  //Object cannot be cast from DBNull to other types
        decimal quantity = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "Quantity"));
        decimal discount = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "TaxPercentage"));
        return unitPrice * quantity * (1 - discount);
    }

    private void gridView1_CustomUnboundColumnData(object sender, DevExpress.XtraGrid.Views.Base.CustomColumnDataEventArgs e)
    {
        GridView view = sender as GridView;
        if (e.Column.FieldName == "Totalototal" && e.IsGetData) e.Value =
          getTotalValue(view, e.ListSourceRowIndex);
    }

Thanks in advance.

Posted 22-Nov-13 1:19am

srihari1904

Updated 26-Sep-16 1:20am

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5 solutions

Solution 2

you copyed the code from there, right?

http://documentation.devexpress.com/#WindowsForms/CustomDocument1477[^]

but please check if you may add something like ".Value" or ".ToString" behind the request.
Like following:

C#

decimal unitPrice = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "Each").Value);

i have no possebilitys tp create a project which contains a GridView right now.
so i just have to guess.

Posted 22-Nov-13 1:35am

Nooa

Updated 22-Nov-13 1:36am

v2

Solution 5

C#

I'm thinking that your output parameter is coming back with a DBNull value. Add a check for that like this

C#

var outputParam = dataAccCom.GetParameterValue(IDbCmd, "op_Id");
if(!(outputParam is DBNull))
     DataTO.Id = Convert.ToInt64(outputParam);

Posted 26-Sep-16 1:20am

Member 12390161

Updated 26-Sep-16 1:21am

v2

Comments

[no name] 26-Sep-16 7:27am

Very well done. The question was asked and answered 3 years ago but those really valuable worthless internet points have you answering anyway.

Solution 4

check your stored procedure and

set variable as set @conducted=0

alter procedure dbo.usp_Batch

(

@batchid int,

@sturegno int,

@intresult int output,

@total int output,

@conducted int output,

@attendent int output

)

as

BEGIN

declare @lec varchar(max)

declare @sql nvarchar(max),@sql1 nvarchar(max),@sql2 nvarchar(max)

declare @out1 nvarchar(max),@out2 nvarchar(max),@out3 nvarchar(max)
set @total=0
set @conducted=0
set @attendent=0

set @intresult=1

Posted 18-Jul-14 20:23pm

shashi keshar

Updated 18-Jul-14 20:24pm

v2

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OriginalGriff · Accepted Answer · 2013-11-22T01:26:00

The error is pretty explicit: "Object cannot be cast from DBNull to other types"
Your database field can (and does) contain SQL NULL values - and when they are returned via a query, the value is a specific code which represents this in a way that your code can check and use: DBNull.Value
There are good reasons why this is not just null - mainly to do with being able to tell the difference between a missing parameter and a null DB value - but if your DB table can contain nulls, then you need to check the returned value to ensure it is not DBNull.Value before you attempt to cast it, as nulls can't be turned into valid objects.

Karthik_Mahalingam · Accepted Answer · 2013-11-22T01:36:00

Solution 3

Try this....

C#

string value =  view.GetListSourceRowCellValue(listSourceRowIndex, "Each") +"" ;
           decimal unitPrice;
           decimal.TryParse(value, out unitPrice);

Posted 22-Nov-13 1:36am

Karthik_Mahalingam