C＃检查文本文件是否包含内容

Question

I am building a C# WPF Browser App (my C# skills are quite rusty).

I have a button that I want to have change color depending on if a text document has anything in it. IE: Color is Green if there is any text in it, or Red if it is empty.

Can someone please push me off in the right direction. Thank you.

Answer 1

Take a look at System.IO.FileInfo

FileInfo f = new FileInfo( "<file path>" );
if( f.Length > 0 ) 
  // Color button green
else 
  // Color button red

Note that if you keep f around and plan to check it again later, you will have to call f.Refresh() to ensure it has the latest information.

Answer 2

Clearly I am very late on this one, but my answer turned into a big blog post.

Here is a full solution using FileSystemWatcher and all the WPF bells and whistles

Hopefully you get some use out of it.

Answer 3

button.Color = (new FileInfo("foo.bar")).Length == 0 ? Color.Red : Color.Green;