Re: Sleep thread but not current - C# Discussion Boards

Unable to cast object of type 'System.DateTime' to type 'System.String'.

private void StudentsDataGridView_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
// Although we could have the SQL statement return a formatted date,
// this is really a User Interface issue and should be handled here.
//
// Display only Date part of datetime
if ((this.StudentsDataGridView.Columns[e.ColumnIndex].Name == this.TeachersDataSet.Students.BirthDateColumn.ColumnName))
{
if (!(e.Value == DBNull.Value))
{
e.Value = DateTime.Parse((string)e.Value).ToLongDateString(); e.FormattingApplied = true;
}
}

}

Learning to Code

Mo John wrote:
Unable to cast object of type 'System.DateTime' to type 'System.String'

The exception says it all. You don't say what's the problem you're having, but if it is what I suspect, use the debugger and have a look at e.Value.

The need to optimize rises from a bad design.My articles[^]

Oh yeah! The problem: When Iinter the birthdate in the field click save it update the database. When I query the database all the data is present. When I try to access the same field on a click button to get data on the persons it will not convert the field. I get the error message.

Trying format the field so only the date will show and not the time.

Learning to Code

modified on Monday, December 15, 2008 12:54 PM

So have a look at the e.Value with the debugger. Especially, check the datatype.

The need to optimize rises from a bad design.My articles[^]

//Code
System.Threading.Thread.Sleep(1000);
//Code

the System.Threading.Thread.Sleep(1000); blocks the current thread for the timeperiod in param and dont let execute the next code to it, like MessageBox. But i want current thread keep running however the code blocked.

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Xmen wrote:
But i want current thread keep running however the code blocked.

Huh? How would that work?

modified 12-Sep-18 21:01pm.

//code
//code
//code
//
//Sleep 1000   <<stop here for 1000 ms but current thread keep running, mean if i want to move a form then it should
//
//next code
//next code
//

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There is no distinction between "Form moving code" and "other code" for the CPU, it's all the same.

If you have some code that needs to be paused, then you need to put it into a second thread and stop this one instead.

regards

modified 12-Sep-18 21:01pm.

Greeeg wrote:
There is no distinction between "Form moving code" and "other code" for the CPU, it's all the same.

dude, it was just an example

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128 bit encrypted signature, crack if you can

Xmen wrote:
dude, it was just an example

I know, and I also told you what you need to do instead.

modified 12-Sep-18 21:01pm.

Hi,

code is either running or your thread is sleeping; there is no sleepwalking in .NET
Did you have a question of some kind?

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. Confused | :confused:

yes, thats why i asked for assurance

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Luc Pattyn wrote:
there is no sleepwalking in .NET

System.Threading.Thread.Sleepwalk(int milliseconds)[^]

I wonder how that'd be implemented though Big Grin | :-D

modified 12-Sep-18 21:01pm.

Greeeg wrote:
System.Threading.Thread.Sleepwalk(int milliseconds)[^]

what is this ? a link ? or a not available reference ?
WTF | :WTF:

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128 bit encrypted signature, crack if you can

Break the code block that exists before the Sleep call to another method, and execute this on another thread, like others have pointed out, is the only way to accomplish what you are asking for.

Jaime Febres
The worst blog in the world

is there any method to check the precedence of operators

C# Language Specification
7.2.1 Operator precedence and associativity[^].

The need to optimize rises from a bad design.My articles[^]

Just scope your algorithms, and you'll be fine. It's better that way anyway.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

i mean there are two operators such as + and *. is there any logic to check which has higher precedence.

my code is...

char a='+',b='*'
bool result = Higher_Precedence(a,b);

public bool Higher_Precedence(char a , char b)
{
?????..
}

i dont know how to identify the higher precedence

Precedence would probably be language-specific, but generally they all follow the same order. Someone else already provided a link for C#. And no, there's no logical way to determine precedence (in the form of a function, or otherwise).

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Hi,

if you have two operators, say + and *, you can figure out their precedence by comparing the
results of the following expressions:
A= 2 + 3 * 4
B= 2 + (3 * 4)
C= (2 + 3) * 4

if A==B and B!=C then * has higher precedence than +
if A==C and B!=C then + has higher precedence than *

you can generate C# code dynamically, as an example see this article[^].

Hence you can build a method that determines precedence for any pair of operators in C#.
You can apply similar techniques to other languages as long as dynamic code generation is supported.

Warning: you need to pick good constant values to make sure B!=C (all zeroes or all ones would be a very bad choice).

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. Confused | :confused:

Seems like a lot of work when the answer is already very well documented.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

The OP wanted to check, not just read about it... So IMO a little experiment would do.
In a later message he was looking for a method, hence I suggested dynamic code.
If he starts implementing all this, he will learn a thing or two.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. Confused | :confused:

Luc Pattyn wrote:
If he starts implementing all this, he will learn a thing or two.

He'll learn that he's wasting his time. I guess that's a valuable lesson, but only if he remembers it the next time.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

thanks Luc Pattyn thats what i wanted..
thanks a lot Smile | :)