在 ToString() 之前检查 null [英] Checking for null before ToString()

问题描述

这是场景...

if (entry.Properties["something"].Value != null)
  attribs.something = entry.Properties["something"].Value.ToString();

虽然有效且工作正常，但对我来说这看起来很难看.如果我在执行 ToString() 之前没有检查空值，那么如果该属性为空值，它就会抛出异常.有没有更好的方法来处理这种情况?

While effective and working correctly, this looks ugly to me. If I don't check for a null before performing the ToString() then it throws an exception if the property was null. Is there a better way to handle this scenario?

非常感谢！

推荐答案

8 年后更新(哇！)以涵盖 c#6 的空条件运算符:

Update 8 years later (wow!) to cover c# 6's null-conditional operator:

var value = maybeNull?.ToString() ?? String.Empty;

其他方法:

object defaultValue = "default";
attribs.something = (entry.Properties["something"].Value ?? defaultValue).ToString()

我也用过这个，虽然不是很聪明但很方便:

I've also used this, which isn't terribly clever but convenient:

public static string ToSafeString(this object obj)
{
    return (obj ?? string.Empty).ToString();
}

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