大约有 45,000 项符合查询结果（耗时：0.0494秒） [XML]
How to do ToString for a possibly null object?
...
C# 6.0 Edit:
With C# 6.0 we can now have a succinct, cast-free version of the orignal method:
string s = myObj?.ToString() ?? "";
Or even using interpolation:
string s = $"{myObj}";
Original Answer:
string s = (myObj ?? String.Empty...
Handling Dialogs in WPF with MVVM
...can be interesting. I can expose an ICommand that when the view invokes it, a dialog can appear.
23 Answers
...
How do I correctly detect orientation change using Phonegap on iOS?
...
This is what I do:
function doOnOrientationChange() {
switch(window.orientation) {
case -90: case 90:
alert('landscape');
break;
default:
alert('portrait');
break;
}
}
window.addEventListener('orientationchange', doO...
How do I resolve git saying “Commit your changes or stash them before you can merge”?
I made some updates on my local machine, pushed them to a remote repository, and now I'm trying to pull the changes to the server and I get the message;
...
Setting up connection string in ASP.NET to SQL SERVER
...
You can also use this, it's simpler. The only thing you need to set is "YourDataBaseName".
<connectionStrings>
<add name="ConnStringDb1" connectionString="Data Source=localhost;Initial Catalog=YourDataBaseName;Integrated Security=Tr...
Getting Chrome to accept self-signed localhost certificate
...certificate for the localhost CN. Firefox accepts this certificate after initially complaining about it, as expected. Chrome and IE, however, refuse to accept it, even after adding the certificate to the system certificate store under Trusted Roots. Even though the certificate is listed as correctly...
Checking if sys.argv[x] is defined
...cept and testing len(sys.argv) isn't all that significant. They're both a bit hackish compared to argparse.
This occurs to me, though -- as a sort of low-budget argparse:
arg_names = ['command', 'x', 'y', 'operation', 'option']
args = dict(zip(arg_names, sys.argv))
You could even use it to gener...
How to use JavaScript regex over multiple lines?
I'd want the PRE block be picked up, even though it spans over newline characters. I thought the 'm' flag does it. Does not.
...
jquery - return value using ajax result on success
I have a small problem with jquery $.ajax() function.
9 Answers
9
...
Difference between Covariance & Contra-variance
... are properties of a mapping function that associates one member of a set with another. More specifically, a mapping can be covariant or contravariant with respect to a relation on that set.
Consider the following two subsets of the set of all C# types. First:
{ Animal,
Tiger,
Fruit,
Bana...