asp.net中如何对文件操作

读取:
private void btnRead_Click(object sender, System.EventArgs e)
{
if(filePath.PostedFile.FileName != "")
{
txtFilePath =filePath.PostedFile.FileName;
fileExtName = txtFilePath.Substring(txtFilePath.LastIndexOf(".")+1,3);

if(fileExtName !="txt" && fileExtName != "TXT")
{
Response.Write("请选择文本文件");
}
else
{
StreamReader fileStream = new StreamReader(txtFilePath,Encoding.Default);
txtContent.Text = fileStream.ReadToEnd();
fileStream.Close();
}
}
}
写入:
private void btnRepaire_Click(object sender, System.EventArgs e)
{
if(filePath.PostedFile.FileName != "")
{
txtFilePath =filePath.PostedFile.FileName;
fileExtName = txtFilePath.Substring(txtFilePath.LastIndexOf(".")+1,3);

if(fileExtName !="txt" && fileExtName != "TXT")
{
Response.Write("请选择文本文件");
}
else
{
StreamWriter fileWrite = new StreamWriter(txtFilePath,false,Encoding.Default);
fileWrite.Write(txtContent.Text);
fileWrite.Close();

}
}
}