Question

我使用c#计算出大量的点（x，y，z），现在想将这些点写进一个记事本文件*.txt。

需要循环写进，但是不能覆盖上一次的数据，应该怎么写程序代码？由于点数据是不同的类别，需要写进文档的时候自己再额外的写进一些标记加以区分，比如写A、B、C，后面跟着数据。谢谢了。

Answer 1

追加写入就行了，键肆方式有很多，比如，至于你怎么区分那就随你的了，比如全用A,x,y,z这种格式，读取的稿指轿时候读出一行后用split切割就行了。

The File class provides three methods to append an existing file.

AppendText
AppendAllText

AppendAllLines
The AppendText method creates a StreamWriter object that appends UTF-8 encoded text to an existing text file.
string fileName = @"C:\Temp\Mahesh.txt";
//示例
int x=3,y=5,z=7;

using (StreamWriter sw =File.AppendText(fileName))
{
sw.WriteLine(string.Format("{0},{1},{2},{3}"逗烂,"A",x,y,z));//示例

sw.WriteLine("--------- Append Text Start ----------");
sw.WriteLine("New author started");
sw.WriteLine("a book on Files Programming ");
sw.WriteLine("using C#");
sw.WriteLine("--------- Append Text End ----------");
}
The AppendAllText method opens a file, appends a specified string to the file and then closes the file. If the file does not exist, this method creates a new file, writes the specified string to the file, and then closes the file.

string fileName = @"C:\Temp\Mahesh.txt";
string appendText = "Append all text method ----";
File.AppendAllText(fileName, appendText);
File.AppendAllText(fileName,"Append some more text");
File.AppendAllText(fileName,"Append all text end");

// Read all text
string readText = File.ReadAllText(fileName);
Console.WriteLine(readText);

The AppendAllLines method appends lines to a file and then closes the file.

// We can read a line from one file and write to other file
string fileName = @"C:\Temp\Mahesh.txt";
string[] lines = File.ReadAllLines(fileName);
// Write all lines to a new file
string outputFileName = @"C:\temp\WriteLinesFile.txt";
File.WriteAllLines(outputFileName, lines);

// Append more lines
string[] moreLines = new string[]{"Line 1 goes here", "Line 2 goes here" };
File.AppendAllLines(outputFileName, moreLines);

// Read all text
string readText = File.ReadAllText(outputFileName);
Console.WriteLine(readText);

追问

亲，你写的是英文注释啊，我理解的不太好，能不能提供一个例子？谢谢

追答

你不用看说明啊，只看代码就行了，第一段就是追加的例子

string fileName = @"C:\Mahesh.txt";//要操作的文件为C盘下的Mahesh.txt
int x=3,y=5,z=7;//示例
using (StreamWriter sw =File.AppendText(fileName))
{
    sw.WriteLine(string.Format("{0},{1},{2},{3}","A",x,y,z));//示例
}

运行之后C盘的Mahesh.txt下就会多出一行A,3,5,7

后面那个是将自定义的一个moreLines数组中的所有数据都添加到文件中

string outputFileName = @"C:\WriteLinesFile.txt";
string[] moreLines = new string[]{"Line 1 goes here", "Line 2 goes here" };
File.AppendAllLines(outputFileName, moreLines);
//之后WriteLinesFile.txt中就会多出两行