用數組中的值替換子字符串

Question

我有一個像這樣的字符串：

string source = hello{1}from{2}my{3}world

像這樣的數組：

var valArray = new[] { "Val0", "Val1", "Val2", "Val3" };

我想用數組中的適當值替換“ {index}”子字符串。

我已經寫了代碼，但是看起來很丑

var valArray = new[] { "Val0", "Val1", "Val2", "Val3" };
var source = "hello{1}from{2}my{3}world";
var substr = source;
string pattern = $"{Regex.Escape(start)}{".+?"}{Regex.Escape(end)}";

foreach (Match m in Regex.Matches(source, pattern))
{
    var value = m.Groups[0].Value;
    var ind = Convert.ToInt32(m.Groups[0].Value.TrimStart(start.ToCharArray()).TrimEnd(end.ToCharArray()));
    substr = substr.Replace(value, valArray[ind]);
}
return substr;

任何提示如何解決這個問題？

謝謝！

Answer 1

我認為您正在尋找String.Format ：

string result = string.Format(source, valArray); // "helloVal1fromVal2myVal3world"

請記住，它是從0開始索引，而不是從1開始。

Answer 2

使用Regex.Replace(string input, string pattern, MatchEvaluator evaluator)

var valArray = new[] { "Val0", "Val1", "Val2", "Val3" };
var source = "hello{1}from{2}my{3}world";

string result = Regex.Replace(
    source,
    "{(?<index>\\d+)}",
    match => valArray[int.Parse(match.Groups["index"].Value)]);

Answer 3

[Test]
public void SO_36103066()
{
    string[] valArray = new[] { "Val0", "Val1", "Val2", "Val3" };
    //prefix array with another value so works from index {1}
    string[] parameters = new string[1] { null }.Concat(valArray).ToArray(); 
    string result = string.Format("hello{1}from{2}my{3}world", parameters);
    Assert.AreEqual("helloVal0fromVal1myVal2world", result);
}