计算目录中的图像文件

Question

我正在尝试枚举和导入文件夹中的多个图像文件。我当前用于计算图像的代码如下 -

Dim fullpath As String
fullpath = TxtPath.Text + "\"


Dim FileDirectory As New IO.DirectoryInfo(fullpath)
Dim FileJpg As IO.FileInfo() = FileDirectory.GetFiles("*.jpg")
Dim FileJpeg As IO.FileInfo() = FileDirectory.GetFiles("*.jpeg")
Dim FileGif As IO.FileInfo() = FileDirectory.GetFiles("*.gif")
Dim FileBmp As IO.FileInfo() = FileDirectory.GetFiles("*.bmp")
Dim FilePng As IO.FileInfo() = FileDirectory.GetFiles("*.png")

Dim count As Integer = 0

For Each File As IO.FileInfo In FileJpg
    count += 1
Next
For Each File As IO.FileInfo In FileJpeg
    count += 1
Next
For Each File As IO.FileInfo In FileGif
    count += 1
Next
For Each File As IO.FileInfo In FileBmp
    count += 1
Next
For Each File As IO.FileInfo In FilePng
    count += 1
Next

有没有更有效的方法在一个 For 循环中执行此操作，而不是 5 个单独的循环 - 您可以将一组文件扩展名发送到 GetFiles 吗？

我还计划使用此代码将这些图像导入数据库，因此在那里使用一个循环也会更有效率。

谢谢！

Answer 1

不是最好的解决方案，但我现在没有时间使用 LINQ。试试这个：

Dim extensions As New List(Of String)
extensions.Add("*.png")
' And so on, until all are in...

Dim fileCount As Integer
For i As Integer = 0 To extensions.Count - 1
  fileCount += Directory.GetFiles(txtPath.Text, extensions(i), SearchOption.AllDirectories).Length
Next

Answer 2

自从我研究 VB.NET 以来已经有一段时间了，但是在 C# 中你可以这样做：

    static void Main(string[] args)
    {
        string filePath = @"I:\Archive\2009.12.21c";

        List<string> extensions = new List<string>{
            ".jpg",
            ".jpeg",
            ".png",
        };

        string[] countImages = System.IO.Directory.GetFiles(filePath);

        foreach (string file in countImages)
        {
            if (extensions.Contains(System.IO.Path.GetExtension(file).ToLowerInvariant()))
            {
                //This is where you can add to your count for found files
            }
        }
    }

这些都是 .NET 类，应该很容易转换回 VB.NET。

---

编辑@Trade

@Trade OK，能够做到。运行你的代码（转换为 C#）和我的代码，我的 6 个循环然后是你的，然后是你的 6 个，然后是我的。你的 6 次，然后是 6 次穿过我的，然后翻转它们（所有这些都是为了确保不是 JIT 预热），结果：与我使用的方法相比，差异超过了一个数量级：

例子：你的是 enum2，我的是 enum1

Found 37 with dir enum1 in 609
Found 37 with dir enum1 in 469
Found 37 with dir enum1 in 462
Found 37 with dir enum1 in 455
Found 37 with dir enum1 in 448
Found 37 with dir enum1 in 406
Found 37 with dir enum2 in 6314
Found 37 with dir enum2 in 6888
Found 37 with dir enum2 in 5439
Found 37 with dir enum2 in 5614
Found 37 with dir enum2 in 5824
Found 37 with dir enum2 in 6342

这是您的方法的转换代码：

private static void enum2(string filePath, List<string> extensions)
{
    System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
    sw.Start();
    int countCount = 0;
    for (int i = 0; i < extensions.Count(); i++)
    {
        string curExt = extensions[i];
        countCount += System.IO.Directory.GetFiles(filePath, "*" +
            curExt, System.IO.SearchOption.TopDirectoryOnly).Length;
    }
    sw.Stop();

    Console.WriteLine("Found {0} with dir enum2 in {1}",
        countCount, sw.ElapsedTicks.ToString());
}