如何避免==空检查？

Question

Here is my code which is used widely in project, and I'm wondering can I refactor this somehow so I might avoid == null checks all the time?

 ActiveCompany = admin.Company == null ? false : admin.Company.Active

Thanks guys

Cheers

Answer 1

You can use the C# 6: Null-conditional Operator

ActiveCompany = admin.Company?.Active == true;

The comparison with true at the end "converts" the bool? to bool . You can also use the null coalescing operator to handle the null value as shown by Keith.

Answer 2

与null条件链接的null合并运算符对于这种情况很有用：-

ActiveCompany =  admin.Company?.Active ?? false

Answer 3

If you find yourself doing this an awful lot, you could write an extension method to simplify the code.

For example, suppose you have these classes:

public sealed class Company
{
    public bool Active { get; set; }
}

public sealed class MyClass
{
    public Company Company;
}

Then you could write an extension method like so:

public static class MyClassExt
{
    public static bool IsActiveCompany(this MyClass myClass)
    {
        return myClass.Company?.Active ?? false;
    }
}

Which would mean you can write code like:

var test = new MyClass();
// ...
bool activeCompany = test.IsActiveCompany();

This doesn't make the code much shorter, but some might think it makes it more readable.