如何检查此文件名是否在c#中创建[重复]

Question

我正在尝试创建一个方法来检查是否创建了此文件 (todayfile.txt)，如果没有，我需要它来创建它。这是我的想法：

private void ReadWater()
    {
        try
        {
            StreamReader inputFile;

            // I want to check if there is a file named ( Todayfile.txt )

            if (// if this file ( Todayfile.txt) is founded)
            {
                // Do this
            }

            else // if there is no file in this nmae ( Todayfile.text )
            {
                // create a new file 
            }

        }
        catch (Exception ex)
        {

        }

    }

Answer 1

您可以使用System.IO.File 类来检查和创建文件。

以下示例演示如何使用File 类检查文件是否存在，并根据结果创建新文件并写入，或打开现有文件并从中读取。

private void ReadWater()
{
    string path = "Todayfile.txt";
    // if there is no file in this name ( Todayfile.txt )
    if(!System.IO.File.Exists(path)) {
        // Create a file to write to.
        using (StreamWriter sw = File.CreateText(path)) {
            sw.WriteLine("Hello");
            sw.WriteLine("And");
            sw.WriteLine("Welcome");
        }
    }
    //at this point file should exist.

    // Open the file to read from.
    using (StreamReader sr = File.OpenText(path)) {
        string s = "";
        while ((s = sr.ReadLine()) != null) {
            Console.WriteLine(s);
        }
    } 
}

查看上面提供的链接以获得System.IO.File 类及其方法的更详细说明。