在/Writing中读取( C# )文件

Question

我最近想跟踪HTTPWebRequest上传进度。因此，我从一个简单文本文件的缓冲读取开始，开始很小。然后我发现一个简单的任务

File.ReadAllText("text.txt");

变成了下面的样子，所有的溪流，读者，作家等等。或者什么东西可以被移除？另外，下面的代码不起作用。也许我做错了什么，如何在缓冲区中读取(我猜写也会类似)，这样我就可以跟踪进度，假设流不是本地的。WebRequest

byte[] buffer = new byte[2560]; // 20KB Buffer, btw, how should I decide the buffer size?
int bytesRead = 0, read = 0;
FileStream inStream = new FileStream("./text.txt", FileMode.Open, FileAccess.Read);
MemoryStream outStream = new MemoryStream();
BinaryWriter outWriter = new BinaryWriter(outStream);

// I am getting "Offset and length were out of bounds for the array or count is greater than the number of elements from index to the end of the source collection."
// inStream.Length = Length = 9335092
// bytesRead = 2560
// buffer.Length = 2560
while ((read = inStream.Read(buffer, bytesRead, buffer.Length)) > 0)
{
    outWriter.Write(buffer);
    //outStream.Write(buffer, bytesRead, buffer.Length);
    bytesRead += read;
    Debug.WriteLine("Progress: " + bytesRead / inStream.Length * 100 + "%");
}
outWriter.Flush();

txtLog.Text = outStream.ToString(); 

更新:解决方案

byte[] buffer = new byte[2560];
int bytesRead = 0, read = 0;
FileStream inStream = File.OpenRead("text.txt");
MemoryStream outStream = new MemoryStream();

while ((read = inStream.Read(buffer, 0, buffer.Length)) > 0)
{
    outStream.Write(buffer, 0, buffer.Length);
    bytesRead += read;
    Debug.WriteLine((double)bytesRead / inStream.Length * 100);
}

inStream.Close();
outStream.Close();

Answer 1

很可能是

outWriter.Write(buffer,0,read);

Answer 2

由于您似乎在阅读文本(尽管我可能错了)，如果您逐个字符地阅读而不是调用标准的read ()，那么您的程序可能会简单得多：

BinaryReader reader = new BinaryReader(File.Open("./text.txt", FileMode.Open));
MemoryStream outStream = new MemoryStream();
StreamWriter outWriter = new StreamWriter(outStream);

while (Reader.BaseStream.Position < Reader.BaseStream.Length)
{
    outWriter.Write(reader.ReadChar());
    Debug.WriteLine("Progress: " + ((double)reader.BaseStream.Position) / (double)(reader.BaseStream.Length) + "%");
}
outWriter.Close();
txtLog.Text = outStream.ToString();

Answer 3

因为您只需要检查上传操作的进度，所以可以使用fileinfo对象检查文件的大小。

在FileInfo类中，有一个名为length的属性，它返回文件大小(以字节为单位)。不确定写入文件时是否给出了当前大小。但我认为值得一试，因为它比你所用的方法更简单、更有效