C#读写txt文件的方法

#region 写入TXT文本文件

/// <summary>
/// StreamWriter写入文本文件
/// </summary>
public void StreamWriterWrite()
{
//文件路径
string filePath = AppDomain.CurrentDomain.BaseDirectory;    // Server.MapPath("~/UploadFiles/");

//文件不存在则创建
if (!System.IO.Directory.Exists(filePath))
{
System.IO.Directory.CreateDirectory(filePath);
}
filePath = AppDomain.CurrentDomain.BaseDirectory + DateTime.Today.ToString("yyyMMdd") + ".txt";

#region 另一种方式
////FileMode.Append,FileAccess.Write追加文件
//FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate);
//StreamWriter sw = new StreamWriter(fs);

#endregion

StreamWriter sw = new StreamWriter(filePath, true);
//Write直接追加文件末尾，不换行;WriteLine直接追加文件末尾，换行
sw.WriteLine("测试StreamWriter写入TXT文件" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:ffff"));

//清空缓冲区、关闭流
sw.Flush();
sw.Close();

//直接追加到文件
//using (System.IO.StreamWriter sw = System.IO.File.AppendText(filePath))
//{
//    sw.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:ffff"));
//}

}

/// <summary>
/// FileStream写入文本文件
/// </summary>
public void FileStreamWrite()
{
//文件路径
string filePath = AppDomain.CurrentDomain.BaseDirectory;    // Server.MapPath("~/UploadFiles/");

//文件不存在则创建
if (!System.IO.Directory.Exists(filePath))
{
System.IO.Directory.CreateDirectory(filePath);
}
filePath = AppDomain.CurrentDomain.BaseDirectory + DateTime.Today.ToString("yyyMMdd") + ".txt";

//1.该方法写入字符数组换行显示
string[] arrFile = { "first line", "second line", "third line", "第四行" };
System.IO.File.AppendAllLines(filePath, arrFile, System.Text.Encoding.Default);

//2.字符串写入文本
string strTest = "该例子测试一个字符串写入文本文件。";
System.IO.File.AppendAllText(filePath, strTest, System.Text.Encoding.Default);

//3.FileMode.Append,FileAccess.Write追加文件
FileStream fs = new FileStream(filePath, FileMode.Append,FileAccess.Write);
byte[] data = System.Text.Encoding.Default.GetBytes("测试FileStream写入TXT文件" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:ffff"));
fs.Write(data, 0, data.Length);
//清空缓冲区、关闭流
fs.Flush();
fs.Close();
}

#endregion