为什么我的StreamWriter没有写入.txt文件？

Question

I am try to write a file but it is still empty ...

 FileStream f = new FileStream("HighScore.txt", 
                                FileMode.OpenOrCreate, 
                                FileAccess.ReadWrite);

 StreamWriter streamWriter = new StreamWriter(f);
 streamWriter.WriteLine("aaaaa");

Has anyone encountered this problem and can help me?

Answer 1

You have to Close the writer; since StreamWriter is IDisposable let's do it with a using :

 using(FileStream f = new FileStream("HighScore.txt", 
                                      FileMode.OpenOrCreate, 
                                      FileAccess.ReadWrite)) {
   using(StreamWriter streamWriter = new StreamWriter(f)) {
     streamWriter.WriteLine("aaaaa");
   }
 }

Usually, writers cache the updates and apply them on closing. If you want to apply changes somewhere the middle of the process , call Flush() . In case you want just to write text to the file you can put it easier

File.WriteAllText("HighScore.txt", "aaaaa");

Answer 2

StreamWriter is buffering your data. The buffered data is automatically flushed when full or when closing the connection, you're not doing any of it.

Your situation is the data is too small, and thus not flushed.

Closing the connection will solve the problem.

You have few options.

Manual Flush - Less recommended

Manually add flush when you want to save the data.

steamWriter.Flush()

Closing the connection manually - better, but still not best.

streamWriter.Close();

Disposing the connection - best.

Wrapping the code with using will dispose the resource when the scope {..} is finished, the dispose operation will close the connection and thus flush your data.

using (var f = new FileStream("HighScore.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite))
using (var streamWriter = new StreamWriter(f))
{
    streamWriter.WriteLine("aaaaa");
}