Hey there! Let's get this sorted for you. The core issue with your current code is that it's grabbing everything from the first -> to just before ->val, but what you actually need is the second-to-last element in that chain—no matter how many elements are in the string.

方法一：用Split分割（推荐，简洁易读） #

Since your string uses a consistent separator ->, the easiest way is to split the string into an array of parts, then pick the element at index length - 2 (arrays are zero-indexed, so this gives us the second-to-last item).

Here's the updated code:

string path = "Value->Value2->Value3->ImportantValue->val";
// Split the string using "->" as the separator
string[] parts = path.Split(new[] {"->"}, StringSplitOptions.None);
// Grab the second-to-last element
string importantValue = parts[parts.Length - 2];

For your example input, this will give you exactly ImportantValue. Even if you add more elements to the front (like A->B->Value->Value2->...->val), this code still works perfectly because it always targets the second-to-last part of the split array.

方法二：用IndexOf定位（适合不想用Split的场景） #

If you prefer to stick with string indexing instead of splitting, you can find the positions of the last two -> separators and extract the text between them:

string path = "Value->Value2->Value3->ImportantValue->val";
// Find the position of the last "->"
int lastSeparator = path.LastIndexOf("->");
// Find the position of the second-to-last "->" (search before the last one)
int secondLastSeparator = path.LastIndexOf("->", lastSeparator - 1);
// Extract the text between these two separators
string importantValue = path.Substring(
    secondLastSeparator + "->".Length,
    lastSeparator - (secondLastSeparator + "->".Length)
);

This works by narrowing down the exact range where your target value sits, avoiding the mistake of starting from the first separator.

Either method will reliably get you the dynamic ImportantValue you need, no matter how long the string grows.

内容的提问来源于stack exchange，提问作者Mysterio