如何在C# Windows中获取文件大小、文件名和文件扩展名？

Question

我是一名新手，正在学习C#.net。请问如何在Windows系统中使用C#获取文件大小、文件名和文件扩展名？

我正在使用C#中的打开文件对话框，但只能获取文件路径，不知道如何获取文件名和大小。

以下是我的代码：

openFileDialog1.ShowDialog();

openFileDialog1.Title = "Select The File";
openFileDialog1.InitialDirectory = "C:";
openFileDialog1.Multiselect = false;
openFileDialog1.CheckFileExists = false;

if (openFileDialog1.FileName != "")
 {
  txtfilepath1.Text = openFileDialog1.FileName;
  var fileInfo = new FileInfo(openFileDialog1.FileName);
  lblfilesize1.Text = Convert.ToString(openFileDialog1.FileName.Length);  

  lblfilesize=
  lblfilename=    
 }

- Guru G

Answer 1

• 文件大小 FileInfo.Length
• 文件名称 FileInfo.Name
• 文件扩展名 FileInfo.Extension

您不需要使用其他类，因为您已经在使用 FileInfo。

- Muhammad Hasan Khan

Answer 2

您可以使用FileInfo类。文件信息

using System;
using System.IO;

class Program
{
    static void Main()
    {
    // The name of the file
    const string fileName = "test.txt";

    // Create new FileInfo object and get the Length.
    FileInfo f = new FileInfo(fileName);
    long s1 = f.Length;

    // Change something with the file. Just for demo.
    File.AppendAllText(fileName, " More characters.");

    // Create another FileInfo object and get the Length.
    FileInfo f2 = new FileInfo(fileName);
    long s2 = f2.Length;

    // Print out the length of the file before and after.
    Console.WriteLine("Before and after: " + s1.ToString() +
        " " + s2.ToString());

    // Get the difference between the two sizes.
    long change = s2 - s1;
    Console.WriteLine("Size increase: " + change.ToString());
    }
}

关于扩展名，您可以使用Path.GetExtension()函数。

- Ravi Gadag

Answer 3

http://msdn.microsoft.com/en-us/library/system.io.fileinfo.aspx

- Derek Beattie