c# - 使用 ASP.net C# 读取文本文件和操作数据

Question

我需要的是测试按日期分组的每一行并计算其中找到的特定模式的数量。在这个例子中找到并计算“D;”每个日期

示例

My expected output to be displayed into textbox

01 - 3

02 - 0

3 - 4

现在，我开始的只是读取文本文件，只显示文本文件中的行数。

 protected void btnRead_Click(object sender, EventArgs e)
    {
        string text = String.Empty;
        int i = 0;
        using (StreamReader stRead = new StreamReader(FileUpload1.PostedFile.InputStream))
        {

            //to write textfile content         
            while (!stRead.EndOfStream)
            {
                //ListBox1.Items.Add(stRead.ReadLine());

                text += stRead.ReadLine() + Environment.NewLine;


                i++;
            }
        }

        TextBox1.Text = text;
        //Label1.Text = i.ToString();
        Label1.Text =  this.TextBox1.Text.Split(new Char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries).Length.ToString();
        //populateListBox();


    }

只是一个关于如何开始的简单想法将是一个很大的帮助。谢谢

Answer 1

你可以使用正则表达式

string test = "D; sjhjsd  D; sdsdjks D;";
MatchCollection collection = Regex.Matches(test, @"[D;]+");
var x= collection.Count;

结果:3

此编辑展示了如何实现上面的 Regex 来计算每个读取的行

protected void btnRead_Click(object sender, EventArgs e)
{
    string text = String.Empty;
    int i = 0;
    int countedChars;
    using (StreamReader stRead = new StreamReader(FileUpload1.PostedFile.InputStream))
    {

        //to write textfile content         
        while (!stRead.EndOfStream)
        {
            var readedLine = stRead.ReadLine() 
            //ListBox1.Items.Add(readedLine );

            if (!string.IsNullOrWhiteSpace(readedLine))
            {
                MatchCollection collection = Regex.Matches(readedLine, @"D;");
                countedChars = collection.Count;
                text += readedLine.Substring(0, readedLine.IndexOf(' ')) +" - "+countedChars + Environment.NewLine;
            }

            i++;
        }
     }

    TextBox1.Text = text;
    //Label1.Text = i.ToString();
    Label1.Text =  this.TextBox1.Text.Split(new Char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries).Length.ToString();
    //populateListBox();


}