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You don't need to do much to get your GUI to handle the threading issue. Just remember (as it seems you already know), never operate on your GUI from another thread.
That being said, I'd do the following:
1. Create a method in your GUI that is accessable from your thread.
2. Create a delegate that matches the signature of the method in step 1.
3. Use the GUI's ability to determine whether it needs invocation on its own thread within the method on the GUI.
4. Check out this 3 part article on MSDN
http://msdn.microsoft.com/library/en-us/dnforms/html/winforms06112002.asp[^]
private delegate void MyUIDelegate (string yourString, int yourInt);
protected void MyGUIMethod(string testString, int testInt)
{
if(this.InvokeRequired)
{
MyUIDelegate myDelegate = new MyUIDelegate (_taskPayne_MyGUIMethod);
this.Invoke(myDelegate , new object[]{ testString, testInt});
}
else
{
... your code here
}
}
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I'm looking for a way to do the following:
class BaseClass
{
public enum Action
{
NO_ACTION
}
protected virtual bool ValidateAction(Action a)
{
return true;
}
}
class DerivedClass : BaseClass
{
public new enum Action
{
ACTION1,
ACTION2
}
protected override bool ValidateAction(Action a)
{
}
}
The above doesn't work because by declaring my enum Action as new in the derived class I've created a totally new type; thus the compiler complains that I shouldn't be trying to override ValidateAction in DerivedClass.
Basically I want to avoid having to use protected bool ValidateAction(int) as my function prototype, thereby avoiding having to cast my enum values to ints all the time to make the call to ValidateAction. Also, this would allow me to call ValidateAction from BaseClass and be sure that my virtual method in DerivedClass gets called.
Is there an obvious way of doing this that I am missing? Deriving from System.Enum to create an Action base class would do the trick, but I've read somewhere that this is poor practice. Any other suggestions?
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By definition an enumeration is not subject to change. Here's a definition right off of MSDN.
"Constants provide a convenient way to set and refer to values that are not expected to change."
Your enum should define all actions that the base and all sub classes can perform. Your sub class doesn't have to handle all the actions, but it does need to use the same enumeration.
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Does anyone know how to create a global mouse hook for the navigation buttons on a 5 button mouse?
I can do a global mouse hook but I only get left,right,middle and one of the XButtons. I need to catch XButton1 and XButton2 separately.
Anyone?
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 I have a Data Table from a Data Set that populates a DataGrid...Good but...
I need to test and iterate through each file name that is stored as a string in the last of three columns (c# Win App) from the Data Table, and see if it exists in a Directory. If not print text to a text file stating "xyz.pdf -- does not exist in directory".
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you've listed a requirement. What's the question?
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I don't know how to go about doing it in c# win app code
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i have in my Employees table a filed that hold the start date of worker
and i nedd to get a message when the worker get 7 month of work
i try to do this :
while (reader.Read())
{
DateTime dt = (DateTime)(reader["Sdate"]);
//DateTime dt2 = new DateTime(dt.Year, dt.Month, dt.Day);
DateTime tomorrow = DateTime.Today.AddDays(360);
TimeSpan Diff = tomorrow - dt;
if (dt > tomorrow && dt < tomorrow)
this.listBox1.Items.Add("העובד " + reader["Fname"].ToString() + " ת.ז" + reader["ID"].ToString() + " נכנס ל 7 חודשי עבודה ");
and its dosent work where is ths problem ?
thanks alllooottt ....
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For one thing, your if statement will never evaluate to true. You're checking the following:
if (dt > tomorrow && dt < tomorrow)
You can never have a date that is greater and less than another date at the same time. Plug in a test value:
if("1/2/2005" > "1/1/2005" && "1/2/2005" < "1/1/2005).... They can't both be true.
Also, if you're trying to check for 7 months why are you adding 360 days? Shouldn't you use
DateTime.Today.AddMonths(7)
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so what do i need to do to make this work ?
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You should really try debugging on your own. It's a good exercise in problem solving. *ALSO NOTE* I'm providing this for reference, without warranty of any kind since I'm totally unclear on your overall goal.
DateTime dt = (DateTime)(reader["Sdate"]);
DateTime dtSevenMonths = DateTime.Today.AddMonths(-7);
if (dt < dtSevenMonths)
{
this.listBox1.Items.Add(......);
}
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i think u solved it  ))
thankssss its semmes to work fine now ....
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Hello:
From a class I want clean a place holder contained in a web form.
I’m using this code:
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace WUC_CreDes
{
public class Class1
{
public static bool Hay_PostBack()
{
WUC_CreDes.WebForm1 parent1 = (WUC_CreDes.WebForm1) this.Page;
parent1.Example.Controls.Clear();
return false;
}
}
}
Where “Example” is my place holder within the web form.
When I compile my Project it’s sending me this error: “Keyword ‘this’ is not valid in a static property, a static method or as startup of static field”.
Does somebody has some idea about how can I attain it?
Thanks you in advance.
Greetings.
A.L.
El hombre que tiene amigos debe mostrarse amigo...
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Finally I attained it thus:
In WebForm1 I did:
bool que = WUC_CreDes.Class1.Hay_PostBack(this);
And in my class I did:
public static bool Hay_PostBack(WUC_CreDes.WebForm1 parent1)
{
parent1.Example.Controls.Clear();
return false;
}
But now I need do same from a WUC, if I do:
bool que = WUC_CreDes.Class1.Hay_PostBack(this);
I understand I need replace 'this' with web form's name, here WebForm1.aspx
Somebody know how can I do to attain it?
El hombre que tiene amigos debe mostrarse amigo...
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If I use: bool que = WUC_CreDes.Class1.Hay_PostBack(this.Page); it's sending me an error when I compile: Argument '1': it's not possible convert from 'System.Web.UI.Page' to 'WUC_CreDess.WebForm1'
May be I'm coding something wrongly but what?
El hombre que tiene amigos debe mostrarse amigo...
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i already did in VB few month ago, and i want to do the same in C#. the function insert in DB the info i get in excel and works well.
' example in VB
public function myFunction(byval LastName as string, byval FirstName as string, optional Email as string="NA", optional PhoneNbr as long=0)
end function
// now how can i do the same in C#?
i can do with polymorphiste but if some function have 20 argument, i need 400 different functions to do the equivalent of vb?
the missing value work, but i need to put all the argument in object type.
Fardoche
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If all ur optional parameters are the same type, u can use the 'params' keyword. U could use it even if they weren't the same type, but u would need to use an object array which u dont want.
Otherwise, the only solution is to overload ur 400 different functions, C# does not support optional parameters.
params[^]
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i am not aware of c# and i have to create one project on c#
so any one can give me a small project of c# with database conectivity. so i can get the idea about my project.
if any one have a project for customizing a printing document then please give me that project
Dipesh Patel
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Hi,
I have a procedure that takes the bill of material for a part
and gets all the routing for each component in the bill.
I would like to create a gant chart in Microsoft Project to show the
time line for creating each component required. I have been
looking all over the place for information on using C# with
Microsoft Project but with not much luck.
Any advice would be great
Thanks
Will
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I want to use a base class to enforce that any children must implement a property and that property must be static and exist at the child class level NOT the base class. The compiler will not allow abstract statics , does anyone know of an elegant work around ?
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Abstract & static would be an oxymoron, something cannot be both as an abstract member implies that a derived class will implement. If it were static there would be no derived class.
Im not sure I personally understand what you are trying to achieve.
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Hi all.
I'm trying to read in the date and time from a binary file that was created using mfc. The cTime class was used to create the time stamp. I'm using a TimeSpan object and a DateTime object in order to get the date and time that was saved in the binary file. i.e.
public Count(BinaryReader read)
{
TimeSpan span = TimeSpan.FromSeconds(read.ReadUInt32());
TimeStamp = new DateTime(span.Ticks);
CountNumber = read.ReadUInt32();
}
The date and time returned ends up coming out as 18/02/0035 16:00:01 which is obviously incorrect as this is old data not future data
I looked at the number of ticks returned in span.Ticks compared to the current number of ticks (at roughly 15:22 today)
632460649505030970 - Today
10771200010000000 - Returned from the file.
As you can see there is a big difference and im pretty sure this data is only a year old at the most.
If anyone knows what i'm doing wrong it would be greatly appreciated.
Cheers
Kev
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