C#中，类似于C中常用的spritf函数，是String.Format函数。
最简单的用法举例如下：
string spritfTestStr = String.Format("Test sprintf in C#, number={0:D}, string=\"{1:s}\", float={2:0.000}", 100, "crifan", Math.PI);
//spritfTestStr = Test sprintf in C#, number=100, string="crifan", float=3.142
关于Format函数的更多的示例，可以参考微软官方文档：String.Format Method (String, Object)
关于其他更多不同类型的参数，比如日期，数值，枚举等，如何指定对应的格式，可以参考：
- For more information about the composite formatting feature supported by methods such as Format, AppendFormat, and some overloads of WriteLine, see Composite Formatting.
- For more information about numeric format specifiers, see Standard Numeric Format Strings and Custom Numeric Format Strings.
- For more information about date and time format specifiers, see Standard DateTime Format Strings and Custom DateTime Format Strings.
- For more information about enumeration format specifiers, see Enumeration Format Strings.
- For more information about formatting, see Formatting Types and Formatting Overview.
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| 1.2. C#中关于字符串的处理 |  | 1.2.2. 字符串的中间对齐左右填充的效果 |
