C# File类常用方法

File 类

　　提供用于创建、复制、删除、移动和打开文件的静态方法，并协助创建 FileStream 对象。　　

　1. File.Exists ——  确定指定的文件是否存在。

　　　public static bool Exists(string path)

string curFile = @"c:\temp\test.txt";
Console.WriteLine(File.Exists(curFile) ? "File exists." : "File does not exist.");

　2. File.AppendAllText 方法 —— 将指定的字符串追加到文件中，如果文件还不存在则创建该文件。

　　　public static void AppendAllText(string path,string contents)

using System;
using System.IO;
using System.Text;

class Test
{
    public static void Main()
    {
        string path = @"c:\temp\MyTest.txt";

        // This text is added only once to the file.
        if (!File.Exists(path))
        {
            // Create a file to write to.
            string createText = "Hello and Welcome" + Environment.NewLine;
            File.WriteAllText(path, createText);
        }

        // This text is always added, making the file longer over time
        // if it is not deleted.
        string appendText = "This is extra text" + Environment.NewLine;
        File.AppendAllText(path, appendText);

        // Open the file to read from.
        string readText = File.ReadAllText(path);
        Console.WriteLine(readText);
    }
}

View Code

　　void public static void AppendAllText(string path,string contents,Encoding encoding)

using System;
using System.IO;
using System.Text;

class Test
{
    public static void Main()
    {
        string path = @"c:\temp\MyTest.txt";

        // This text is added only once to the file.
        if (!File.Exists(path))
        {
            // Create a file to write to.
            string createText = "Hello and Welcome" + Environment.NewLine;
            File.WriteAllText(path, createText, Encoding.UTF8);
        }

        // This text is always added, making the file longer over time
        // if it is not deleted.
        string appendText = "This is extra text" + Environment.NewLine;
        File.AppendAllText(path, appendText, Encoding.UTF8);

        // Open the file to read from.
        string readText = File.ReadAllText(path);
        Console.WriteLine(readText);
    }
}

View Code