ASP.NET 2.0和ObjectDataBinding [英] ASP.NET 2.0 and ObjectDataBinding
问题描述
我正在做一个ASP.NET 2.0项目,我有一个BAL和DAL层。我是
将数据集从DAL传递给BAL。 BAL正在将泛型传回
到演示文稿中。一切正常,但是,我注意到我的
代码在BAL中做了类似的问题:
List< JobSummary> jobSummary = new List< JobSummary>();
foreach(ds.Tables [0] .Rows中的DataRow行)
{
jobSummary.Add(new JobSummaryClass((Int32)row [" JobNum"],
(DateTime)row [" StartDate"],(DateTime)row [" EndDate"] ));
}
返回jobSummary
我在上面的jobSummary.Add()上收到了一个INvalidCastException。我注意到在某些行上,我的EndTime为空。我暂时修复了这个
,将代码包含在try / catch中,而不是重新抛出异常。但是
然后跳过这条记录。
如何解决这个问题有什么选择?
你可以使用
if(row [" StartDate"]!= DBNull.Value)
{
//
}
或
if(!row.IsNull(" StartDate"))
{
//
}
HTH
埃尔顿王
" dm1608"写道:
我正在做一个ASP.NET 2.0项目,我有一个BAL和DAL层。我将DataSet从DAL传递给BAL。 BAL正在将泛型传递回演示文稿。一切正常,但是,我注意到我的
代码在BAL中做了类似的问题:
List< JobSummary> jobSummary = new List< JobSummary>();
foreach(ds.Tables [0] .Rows中的DataRow行)
{jobSummary.Add(new JobSummaryClass((Int32) )row [" JobNum"],
(DateTime)row [" StartDate"],(DateTime)row [" EndDate"]));
}
return jobSummary
我在上面的jobSummary.Add()上收到了一个INvalidCastException。我注意到在某些行上,我的EndTime为空。我暂时修复了这个
,将代码放在try / catch中,而不是重新抛出异常。但是
然后跳过这条记录。
如何解决这个问题有什么选择?
< blockquote>但我需要为EndTime DateTime变量赋值NULL,以便
填充我的集合以供显示。我如何解决这个问题?
" Elton W" <埃尔**** @ discussions.microsoft.com>在消息中写道
新闻:EA ********************************** @ microsof t.com ...
你可以使用
if(row [" StartDate"]!= DBNull.Value)
{
/ /
或
if(!row.IsNull(" StartDate"))
{
//
}
HTH
Elton Wang
" dm1608"写道:
我正在做一个ASP.NET 2.0项目,我有一个BAL和DAL层。我将DataSet从DAL传递给BAL。 BAL正在将仿制品传回给演示文稿。一切正常,但是,我注意到我的
代码在BAL中做了类似的问题:
List< JobSummary> jobSummary = new List< JobSummary>();
foreach(ds.Tables [0] .Rows中的DataRow行)
{jobSummary.Add(new JobSummaryClass((Int32) )row [" JobNum"],
(DateTime)row [" StartDate"],(DateTime)row [" EndDate"]));
}
return jobSummary
我在上面的jobSummary.Add()上收到了一个INvalidCastException。我注意到在某些行上,我的EndTime为空。我暂时修复了
这个
把代码放在try / catch中,而不是重新抛出异常。
但是
然后就会跳过这条记录。
<如何解决这个问题我有哪些选择?
>但是我需要为EndTime DateTime变量赋值NULL,以便填充我的集合以供显示。我如何解决这个问题?
如何使用Nullable DateTime? - 如果
值为DBNull,则不要指定任何内容。
class JobSummaryItem
{
// ...
公共日期时间?结束时间
{
得到{...}
}
}
I''m doing an ASP.NET 2.0 project where I have a BAL and DAL layer. I''m
passing a DataSet from the DAL to the BAL. The BAL is passing generics back
to the presentation. All works fine, however, I noticed a problem with my
code that does something like this in the BAL:
List<JobSummary> jobSummary = new List<JobSummary>();
foreach (DataRow row in ds.Tables[0].Rows)
{
jobSummary.Add(new JobSummaryClass((Int32)row["JobNum"],
(DateTime)row["StartDate"],(DateTime)row["EndDate"]));
}
return jobSummary
I''m receiving an INvalidCastException on my jobSummary.Add() above. I
noticed that on some rows, my EndTime is null. I''m temporarily fixed this
by enclosing the code in a try/catch and not rethrowing the exception. But
then this record is skipped.
What are my options with how to fix this?
You can use
if (row["StartDate"] != DBNull.Value)
{
//
}
or
if (!row.IsNull("StartDate"))
{
//
}
HTH
Elton Wang
"dm1608" wrote:
I''m doing an ASP.NET 2.0 project where I have a BAL and DAL layer. I''m
passing a DataSet from the DAL to the BAL. The BAL is passing generics back
to the presentation. All works fine, however, I noticed a problem with my
code that does something like this in the BAL:
List<JobSummary> jobSummary = new List<JobSummary>();
foreach (DataRow row in ds.Tables[0].Rows)
{
jobSummary.Add(new JobSummaryClass((Int32)row["JobNum"],
(DateTime)row["StartDate"],(DateTime)row["EndDate"]));
}
return jobSummary
I''m receiving an INvalidCastException on my jobSummary.Add() above. I
noticed that on some rows, my EndTime is null. I''m temporarily fixed this
by enclosing the code in a try/catch and not rethrowing the exception. But
then this record is skipped.
What are my options with how to fix this?
But I need to assign NULL to the EndTime DateTime variable in order to
populate my collection for display. How do I get around this?
"Elton W" <El****@discussions.microsoft.com> wrote in message
news:EA**********************************@microsof t.com...You can use
if (row["StartDate"] != DBNull.Value)
{
//
}
or
if (!row.IsNull("StartDate"))
{
//
}
HTH
Elton Wang
"dm1608" wrote:I''m doing an ASP.NET 2.0 project where I have a BAL and DAL layer. I''m
passing a DataSet from the DAL to the BAL. The BAL is passing generics
back
to the presentation. All works fine, however, I noticed a problem with
my
code that does something like this in the BAL:
List<JobSummary> jobSummary = new List<JobSummary>();
foreach (DataRow row in ds.Tables[0].Rows)
{
jobSummary.Add(new JobSummaryClass((Int32)row["JobNum"],
(DateTime)row["StartDate"],(DateTime)row["EndDate"]));
}
return jobSummary
I''m receiving an INvalidCastException on my jobSummary.Add() above. I
noticed that on some rows, my EndTime is null. I''m temporarily fixed
this
by enclosing the code in a try/catch and not rethrowing the exception.
But
then this record is skipped.
What are my options with how to fix this?
> But I need to assign NULL to the EndTime DateTime variable in order topopulate my collection for display. How do I get around this?
How about using a Nullable DateTime? - and then don''t assign anything if the
value is DBNull.
class JobSummaryItem
{
// ...
public DateTime? EndTime
{
get { ... }
}
}
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