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You can define your own Status type (class or struct). It could have whatever public fields (or better properties) you like.
You would instantiate such type like any other. Maybe so:
public Status RunReport() {
...
Status status=new Status(true);
return status;
}
However, seeing you are thinking "Exception", why not use real exceptions, i.e. return results when all goes well, and throw an Exception when something goes wrong, so the caller can catch that Exception?
Goalie35 wrote: Status.Exception (boolean)
Status.Exception.Message (string)
That is not possible. Either Exception is a boolean and it hasn't subfields; or it is a composite type (with fields/properties Message, StackTrace, etc.) and then it doesn't have an overall boolean value.
I would suggest you return to your C# book and read the chapters on classes, and Exceptions.
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It is actually possible (but note, OP, this is a flight of intellectual fancy and don't do this in real code):
class MyExceptionThing {
public string Message { get; set; }
public string StackTrace { get; set; }
public static implicit operator bool(MyExceptionThing thing) { return Message != null; }
}
class Status {
public MyExceptionThing Exception { get; private set; }
}
Custom implicit cast operators can cover a multitude of sins!
I too recommend that you do what Luc says here and expose an actual Exception (i.e. System.Exception, something that you can use throw on) if you want that information available in a status object. There is precedent for this in the Task Parallel Library and BackgroundWorker. Then you can check for
if(status.Exception != null){ ... }
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Thanks Bob. I didn't know that, however I never felt a need for it either. I don't think I'll ever use it...
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if you had a status object with an Exception field, then you'd test for an exception as follows:
if (status.Exception != null)
{
...
}
alternatively, you could have a "computed" property Success as follows
public class Status
{
...
public Exception Exception { get; set; }
...
public bool Success { get { return Exception == null; } }
...
}
then use it as follows:
if (status.Success)
{
...
}
If your actions inspire others to dream more, learn more, do more and become more, you are a leader.-John Q. Adams
You must accept one of two basic premises: Either we are alone in the universe, or we are not alone in the universe. And either way, the implications are staggering.-Wernher von Braun
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.-Albert Einstein
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ToBick wrote: if any .net control is available to compare pictures like it is done with the following Flash-Control:
Your example shows two pictures side by side. I do not see a "comparison".
ToBick wrote: If not - how would you realize this in C#?
I'd load two images in two panels.
Please explain a bit more what needs be compared (picture size, colors, what?), who should do the comparison (the computer, or the user? Your example implies that the user is going to compare them by looking at them) and what the result should be like.
Bastard Programmer from Hell 
if you can't read my code, try converting it here[^]
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Hi,
what i'd like to do is shown also in the following link:
http://www.spiegel.de/panorama/vorher-nachher-grafik-so-verheerend-war-der-tsunami-a-750653.html[^]
Basically, i want to put two pictures above each other and have a "slider" which i can move with the mouse to the left or the right - the part left to the slider belongs to picture No. 1 and the part right to the slider belongs to picture No. 2
Thereby, i can compare a picture which shows the same object before and after a modification.
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A SplitContainer[^] control. Drop two Panels onto it, and draw the appropriate part of the image manually.
--that would assume WinForms, not WPF or web; what UI are you targetting?
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Winforms - so i'll try it like that. However i'm not sure if the width of the split-container slider is not a little bit too high - what do you think how the performance would be (size of both pictures is < 100kb) if i just use one picture box in which i draw the picture depending on the mouse position - i could also just create a line from bottom to top at where the mouse pointer is to seperate it + show an icon as a handle...
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I think performance will largely depend on the bitmaps used, their dimensions and their depth. I think the performance would be quite well, it's not a very heavy task cpu-wise.
The width of the slider can be set using a property, and a PictureBox doesn't add much over a Panel. You'd still have to draw it yourself, and, after a mousemove, invalidate and repaint the affected part - not the entire bitmap.
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Your biggest performance hit will come with the algorithm that you use to generate the "after" image. That's where most of the computation will occur.
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There is no direct API available for this.
However, some articles like this[^] could come to your aid - do a search on the internet and you will find more blogs that could help you.
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Hello there. I have a class which is designed to have only one instance. I instantiate this class in the main dialog. Then in one of my tabs, I try to get this class' object but it stated
Object reference not set to an Instance of an object
Here is what I am trying to far.
public class SingleClass
{
public SingleClass SingleObj {get;set;}
public MainDlg MainDlgObj {get;set;}
public SingleClass(ref MainDlg main)
{
SingleObj = this;
MainDlgObj = main;
}
}
public class MainDlg
{
SingleClass sc;
public MainDlg()
{
var MainDlgObj = this;
sc = new SingleClass(ref MainDlgObj);
}
public void ShowMessage()
{
MessageBox.Show("Hello From MainDlg");
}
}
Now in one of my tabs in this main dialog, I am trying to call this ShowMessage() method via SingleClass like this but it gives the said error
public class Tab1
{
SingleClass sc;
public void Function_InTab()
{
sc.SingleObj.MainDlgObj.ShowMessage();
}
}
The code compiles well but it fails at runtime with the said error. How can I show ShowMessage() here? Thanks for any input.
This world is going to explode due to international politics, SOON.
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Without using static, your classes here must be instantiated. I must say though, that your hierarchy is a complete mess. You need to do a rewrite of this - you might possibly want to consider something like this:
public interface IMessage
{
void ShowMesage();
}
public class MainDialog : IMessage
{
public MainDialog() {}
public void ShowMessage()
{
MessageBox.Show("Hello");
}
}
public static class SingleObj
{
public static void ShowMessage<T>() where T : IMessage, new()
{
T dialog = new T();
dialog.ShowMessage();
}
}
public class Tab1
{
public void Function_InTab()
{
SingleObj.ShowMessage<MainDialog>();
}
}In this code sample, you can see the use of the static modifier to make ShowMessage single instance. More importantly, you can see that we have used generics with constraints to get a somewhat more pleasing design for the case where we simply want to show a message. You can extend and adapt this as to cater for more complex designs, but bear in mind that a single instance class can often be considered to be a code smell - make sure you use it wisely.
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AmbiguousName wrote: I have a class which is designed to have only one instance.
Why not simply use a static class?
KISS.
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Eddy Vluggen wrote: Why not simply use a static class?
I would love to but in my current environment, they are considered plague 
This world is going to explode due to international politics, SOON.
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AmbiguousName wrote: I would love to but in my current environment, they are considered plague
..may I ask "why"?
Singletons are so common that the Framework provides a built-in version. I seriously like to hear any argument on not using them. Enlighten me, why do you take the long road when there's a well documented shortcut that has been specially built for that purpose?
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Well I myself like static stuff very much. But the only answer I am provided is that: debugging becomes very tough. Two things are considered plague here.
1 - Static stuff
2 - extern
Experience speaks for itself. May they are right in their decisions. But at the moment I want to do this without static.
This world is going to explode due to international politics, SOON.
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AmbiguousName wrote: But at the moment I want to do this without static.
I'll shut up then
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Static can be abused and lead to very bad programming practices which is probably why they are considered bad.
However, a corectly implemented Singleton[^] is a special use case that fits your situation perfectly so should be used IMO.
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Thank you for the link. This was really informative for me.
This world is going to explode due to international politics, SOON.
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Singletons are just static classes hidden behind a layer of obfuscation. They are worse
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BobJanova wrote: Singletons are just static classes hidden behind a layer of obfuscation
Would you care to expand on this as I'm pretty sure that's incorrect?
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Sure. Access to a true singleton is via a static method (the getter of an Instance property in C#, but it's still a method). By definition, you can only get one instance, so there's only one available area for state storage, and the type of that instance is known at instantiation time.
The only one of those things that is not directly repeatable by a static class is the last, if you have some sort of factory that returns an instance for a singleton based on something else. Even then, you can delegate the methods which have actually changed from static methods. And such a method would normally be indicative that you should be using dependency management instead of manually coded singletons, anyway.
Let's look at a simple example, in pseudo:
singleton class MyClass {
public static singleton Instance { create { return new MyClass() } };
private int nextID = 100;
public int NextValue() { return nextID++; }
}
This can be directly replaced with
static class MyClass {
private static int nextID = 100;
public static int NextValue() { return nextID++; }
}
... that is, by making all methods and state static, and removing the singleton code. This also means that you aren't wasting memory for an object instance that is there simply to wrap methods and application-wide (i.e. static) state.
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Thanks for your reply.
There are a couple of other things that you can do with a singleton that you can't do with a static class...
A singleton, being a class instance, can be passed as a parameter, be inherited from, implement interfaces and probably many other things too.
I take your points (all valid) on board, but I still feel that there is a distinct, and often benificial, difference to a static class.
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