c# winform 创建文件，把值写入文件，读取文件里的值，修改文件的值，对文件的创建，写入，修改...

创建文件和读取文件的值

#region 判断文件是否存在，不存在则创建，否则读取值显示到窗体

public FormMain()
{
	InitializeComponent();

	//ReadFile(Application.StartupPath + "\\AlarmSet.txt");

	//也是判断文件是否存在
	//System.IO.DirectoryInfo info = new System.IO.DirectoryInfo(Application.StartupPath + "\\AlarmSet.txt");
	//MessageBox.Show(info.Exists.ToString());

	//MessageBox.Show(Application.StartupPath + "\\AlarmSet.txt");

	//判断文件是否存在
	if (!File.Exists(Application.StartupPath + "\\AlarmSet.txt"))
	{
		//File.Create(Application.StartupPath + "\\AlarmSet.txt");//创建该文件

		FileStream fs1 = new FileStream(Application.StartupPath + "\\AlarmSet.txt", FileMode.Create, FileAccess.Write);//创建写入文件 
		StreamWriter sw = new StreamWriter(fs1);
		sw.WriteLine("[runtype]");//开始写入值
		sw.WriteLine("type=1");

		sw.WriteLine("\r\n");

		sw.WriteLine("--报警设置 PPWS 号牌匹配位数 PPWZ 匹配位置 0前匹配 1后匹配");
		sw.WriteLine("[Alarm]");
		sw.WriteLine("PPWZ=0");
		sw.WriteLine("PPWS=8");

		sw.WriteLine("\r\n");

		sw.WriteLine("[Server]");
		sw.WriteLine("ListenPort=2005");

		sw.WriteLine("\r\n");

		sw.WriteLine("[Form]");
		sw.WriteLine("PPWZ=0");

		sw.Close();
		fs1.Close();

	}

	//读取文件值并显示到窗体 
	FileStream fs = new FileStream(Application.StartupPath + "\\AlarmSet.txt", FileMode.Open, FileAccess.ReadWrite);
	StreamReader sr = new StreamReader(fs);
	string line = sr.ReadLine();
	int curLine = 0;
	while (line != null)
	{
		if (++curLine == 7 && line.Equals("PPWZ=0"))//文件第7行并且值为PPWZ=0的时候设置单选钮选中前匹配
		{
			radioButton1.Checked = true;
			radioButton2.Checked = false;
			//MessageBox.Show("前");	
		}
		else if (curLine == 8 && line.Equals("PPWZ=1"))//文件第8行并且值为PPWZ=1的时候设置单选钮选中后匹配
		{
			radioButton2.Checked = true;
			radioButton1.Checked = false;
			//MessageBox.Show("后");
		}

		if (curLine == 8)//文件第8行
		{
			textBox1.Text = line.Substring(line.LastIndexOf("=") + 1);//截取=号后边的值
		}

		//MessageBox.Show("第" + (++curLine).ToString() + "行:   " + line);
		//Console.WriteLine("第" + (++curLine).ToString() + "行:   " + line);
		line = sr.ReadLine();
	}
	sr.Close();
	fs.Close();
}

#endregion

修改文件的值

#region 保存设置 按钮 按下

private void button6_Click(object sender, EventArgs e)
{
	if(radioButton1.Checked == true )
	{
		EditFile(7, "PPWZ=0", Application.StartupPath + "\\AlarmSet.txt");
		EditFile(8, "PPWS=" + textBox1.Text, Application.StartupPath + "\\AlarmSet.txt");
	}

	if (radioButton2.Checked == true)
	{
		EditFile(7, "PPWZ=1", Application.StartupPath + "\\AlarmSet.txt");
		EditFile(8, "PPWS=" + textBox1.Text, Application.StartupPath + "\\AlarmSet.txt");
	}
}

#endregion


#region 设置匹配

public static void EditFile(int curLine, string newLineValue, string patch)
{
	FileStream fs = new FileStream(patch, FileMode.Open, FileAccess.Read);
	StreamReader sr = new StreamReader(fs, Encoding.GetEncoding("utf-8"));//解决写入文件乱码
	string line = sr.ReadLine();
	StringBuilder sb = new StringBuilder();
	for (int i = 1; line != null; i++)
	{
		sb.Append(line + "\r\n");
		if (i != curLine - 1)
			line = sr.ReadLine();
		else
		{
			sr.ReadLine();
			line = newLineValue;
		}
	}
	sr.Close();
	fs.Close();
	FileStream fs1 = new FileStream(patch, FileMode.Open, FileAccess.Write);
	StreamWriter sw = new StreamWriter(fs1);
	sw.Write(sb.ToString());
	sw.Close();
	fs.Close();
}

#endregion

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