Question

Trying to convert some VB to C#... (learning C#, too). I have some code that loops through files in a directory and retrieves their file information. I have this originally in VB, but am trying to learn C#, and the online convertors don t give me code that will pass .net 2.0.

Here is the error: Type and identifier are both required in a foreach statement

这里,我有:

DirectoryInfo dirInfo = new DirectoryInfo(currentDir);
FileInfo[] files = null;
files = dirInfo.GetFiles();

FileInfo f = default(FileInfo);
foreach (f in files) {  ...
}

I tried putting foreach(FileInfo f... but it gives me a different error: A local variable named f cannot be declared in this scope because it would give a different meaning to f , which is already used in a parent or current scope to denote something else

我如何确定这一点?

Answer 1

DirectoryInfo dirInfo = new DirectoryInfo(currentDir);
FileInfo[] files = null;
files = dirInfo.GetFiles();

// I removed the declaration of f here to prevent the name collision.
foreach (FileInfo f in files)
{  ...
}

这里是一部更简单的法典:

DirectoryInfo dirInfo = new DirectoryInfo(currentDir);
foreach (FileInfo f in dirInfo.GetFiles())
{
}

Answer 2

这里,它希望你再犯:

FileInfo f = default(FileInfo);
foreach (f in files) {  ...
}

你们正在 lo子外面界定 f,然后试图在 lo体内加以界定。

如果你需要缺省,则尝试:

FileInfo f = default(FileInfo);
foreach (FileInfo file in files)
    {
         relevant code here
    }

否则删除宣布变数“f”的声明

Answer 3

您应提供体内使用的变量类型。您将采用<代码>FileInfo。但是,如果是C# 3.0或之后,你只能写上var<>/code>,汇编者将照发:



foreach (FileInfo f in files) 
{  
   // ...
}


http://msdn.microsoft.com/en-us/library/a664754%28v=vs.71%29.aspx”rel=“nofollow”>。

完整的解决办法(现在不需要先入代变数和档案系列):

DirectoryInfo dir = new DirectoryInfo(currentDir);
foreach (FileInfo file in dir.GetFiles()) 
{
   // use file  
}

Answer 4

这一工作应当:

        DirectoryInfo dirInfo = new DirectoryInfo(currentDir);
        FileInfo[] files = null;
        files = dirInfo.GetFiles();
        foreach (FileInfo f in files)
        {
        }

Edit:

我认为,这将更清洁:

        foreach (FileInfo f in new DirectoryInfo(currentDir).GetFiles())
            {
            }

友情链接