c# - 填充字符数组或字符串——寻找更好的方法

Question

<分区>

Answer 1

我喜欢这个问题:)

这是我的做法。真的很期待其他人，因为这真的很有趣:)

public class Program
{
    public static void Main(string[] args)
    {
        PrintHourGlass(25);
    }

    /// <summary>
    /// Prints an hour glass starting at the given offset
    /// </summary>
    /// <param name="indent">The starting offset</param>
    static void PrintHourGlass(int indent)
    {
        PrintAsteriks(indent, 5); // offset = indent, print 5 *          [I]*****
        PrintAsteriks(indent + 1, 3); // offset = indent + 1, print 3 *  [I] ***
        PrintAsteriks(indent + 2, 1); // offset = indent +3, print 1 *   [I]  *
        PrintAsteriks(indent + 1, 3); // offset = indent + 1, print 3 *  [I] ***
        PrintAsteriks(indent, 5); // offset = indent, print 5 *          [I]*****
    }

    /// <summary>
    /// Prints given number of * characters starting from the given offset
    /// </summary>
    /// <param name="indent">The starting offset</param>
    /// <param name="asterisks">The number of * characters to print</param>
    static void PrintAsteriks(int indent, int asterisks)
    {
        // Check starters guide to string.Format here:
        // https://msdn.microsoft.com/en-us/library/system.string.format(v=vs.110).aspx#Starting

        // string format uses a template and allows you to pass in and format arguments as you like.
        // The template below evaluates to {0,25}{1} for indent = 25 and asteriks = 5
        // which means,
        // print argument 0 (first parameter), no extra formatting, pad the output to 25 characters
        // print argument 1, no formatting
        string formatString = "{0," + indent + "}{1}";

        // Console.WriteLine method uses string.Format internally
        // Below, for the template, argument 0 is null
        //     (since we want to print only 25 characters, the padding.
        //     The value could have been "" instead of null)
        // Argument 1 is a string of * characters, with the length specified by asteriks parameter
        Console.WriteLine(formatString, null, new string('*', asterisks));

        // Therefore, it outputs 25 linear white spaces, then 5 * characters.
    }
}