iskm/learnxinyminutes-docs
1
0
Fork 0
mirror of https://github.com/adambard/learnxinyminutes-docs.git synced 2024-12-23 09:41:36 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[CSharp/en]Added exception handling

Browse Source
This commit is contained in:
Laoujin 2015-01-31 23:14:58 +01:00
parent dc34af2b5d
commit 710f9fa03b
1 changed files with 34 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
csharp.html.markdown
View File

@ -462,6 +462,31 @@ on a new line! ""Wow!"", the masses cried";
Func<int, int> square = (x) => x * x; // Last T item is the return value
Console.WriteLine(square(3)); // 9
// ERROR HANDLING - coping with an uncertain world
try
{
var funBike = PennyFarthing.CreateWithGears(6);
// will no longer execute because CreateWithGears throws an exception
string some = "";
if (true) some = null;
some.ToLower(); // throws a NullReferenceException
}
catch (NotSupportedException)
{
Console.WriteLine("Not so much fun now!");
}
catch (Exception ex) // catch all other exceptions
{
throw new ApplicationException("It hit the fan", ex);
// throw; // A rethrow that preserves the callstack
}
// catch { } // catch-all without capturing the Exception
finally
{
// executes after try or catch
}
// DISPOSABLE RESOURCES MANAGEMENT - let you handle unmanaged resources easily.
// Most of objects that access unmanaged resources (file handle, device contexts, etc.)
// implement the IDisposable interface. The using statement takes care of
@ -780,10 +805,17 @@ on a new line! ""Wow!"", the masses cried";
}
set
{
throw new ArgumentException("You can't change gears on a PennyFarthing");
throw new InvalidOperationException("You can't change gears on a PennyFarthing");
}
}
public static PennyFarthing CreateWithGears(int gears)
{
var penny = new PennyFarthing(1, 1);
penny.Gear = gears; // Oops, can't do this!
return penny;
}
public override string Info()
{
string result = "PennyFarthing bicycle ";
@ -842,7 +874,7 @@ on a new line! ""Wow!"", the masses cried";
## Topics Not Covered
* Attributes
* Exceptions, Abstraction
* Abstraction
* ASP.NET (Web Forms/MVC/WebMatrix)
* Winforms
* Windows Presentation Foundation (WPF)