c# - 需要比较从单独的 foreach 循环产生的值

Question

我有两个foreach循环，每个循环遍历一个文本文件，只获取前两列的所有值的值(文本文件中有两列以上，用“|”分隔) ) 并将其放入字符串中。我想比较这些 foreach 循环的结果(Response.Write 语句输出的值)以查看字符串是否等效。任何想法/建议表示赞赏。

protected void Page_Load(object sender, EventArgs e)
{
    string textFile1 = @"C:\Test\Test1.txt";
    string textFile2 = @"C:\Test\Test2.txt";
    string[] textFile1Lines = System.IO.File.ReadAllLines(textFile1);
    string[] textFile2Lines = System.IO.File.ReadAllLines(textFile2);
    char[] delimiterChars = { '|' };

    foreach (string line in textFile1Lines)
    {
        string[] words = line.Split(delimiterChars);
        string column1And2 = words[0] + words[1];
        Response.Write(column1And2);
    }

    foreach (string line in textFile2Lines)
    {
        string[] words = line.Split(delimiterChars);
        string column1And2 = words[0] + words[1];
        Response.Write(column1And2);
    }
}

Answer 1

比较输出的一种方法是随时存储字符串，然后使用 SequenceEqual 比较结果。 .由于这两个循环是相同的，请考虑从中创建一个静态方法:

// Make the extraction its own method
private static IEnumerable<string> ExtractFirstTwoColumns(string fileName) {
    return System.IO.File.ReadLines(fileName).Select(
         line => {
              string[] words = line.Split(delimiterChars);
              return words[0] + words[1];
         }
    );
}

protected void Page_Load(object sender, EventArgs e)
    // Use extraction to do both comparisons and to write
    var extracted1 = ExtractFirstTwoColumns(@"C:\Test\Test1.txt").ToList();
    var extracted2 = ExtractFirstTwoColumns(@"C:\Test\Test2.txt").ToList();
    // Write the content to the response
    foreach (var s in extracted1) {
        Response.Write(s);
    }
    foreach (var s in extracted2) {
        Response.Write(s);
    }
    // Do the comparison
    if (extracted1.SequenceEqual(extracted2)) {
        Console.Error.WriteLine("First two columns are different.");
    }
}