Question

string.Format定义的详尽列表为

public static String Format(IFormatProvider provider,String format, params object[] args);
public static String Format(String format, params object[] args);
public static String Format(String format, object arg0, object arg1, object arg2);
public static String Format(String format, object arg0);
public static String Format(String format, object arg0, object arg1);

和以下代码

using System;

public class Program
{
    public static void Main()
    {
        var myFormat = "(0:'{0}';1:'{1}')";
        var myParams = new object[] {"arg1", "arg2"};       

        var myString = MyTest(myFormat, myParams);

        Console.WriteLine(myString);
    }

    public static string MyTest(string format, params object[] args)
    {
        string myFirstArg = "arg0";
        var result = string.Format(format, myFirstArg, args);
        return result;
    }
}

会给予

(0:'arg0';1:'System.Object[]')

现在的问题是如何将arg0中的myParams包括进来，以便输出

(0:'arg0';1:'arg1';2:'arg2')

PS。（假设myFormat = "(0:'{0}';1:'{1}';2:'{2}')";）

Answer 1

您可以使用LINQ：

public static string MyTest(string format, params object[] args)
{
    string myFirstArg = "arg0";
    var result = String.Format(format, (new[] { myFirstArg }).Union(args).ToArray());
    return result;
}

Answer 2

您必须创建一个以arg0作为第一个元素的数组。试试这个：

using System.Linq;
public static string MyTest(string format, params object[] args) {
    var newarr = new object[] { "arg0" };
    newarr.Concat(args);
    var result = string.Format(format, newarr);
    return result;
}

Answer 3

我将 Prepend 扩展方法用于此类任务：

class Program
{
    static void Main()
    {
        string myFirstArg = "arg0";
        var format = "(0:'{0}';1:'{1}';2:'{2}')";
        var args = new object[] { "arg1", "arg2" };
        var result = string.Format(format, args.Prepend(myFirstArg).ToArray());
    }
}
public static class IEnumerableExtensions
{
    public static IEnumerable<T> Prepend<T>(this IEnumerable<T> collection, T element)
    {
        yield return element;
        foreach (var e in collection) yield return e;
    }
}

在“参数”（C＃）中包含另一个参数

3 个答案: