Question

我有这段代码，我将按顺序运行以下代码。

我将始终在开头创建一个新的文本文件。然后对于代码的第2和第3部分，我只需要附加文本文件“checksnapshot”我如何使用streamwriter来做到这一点？

//1
using (StreamReader sr = new StreamReader("C:\\Work\\labtoolssnapshot.txt")) ;
{
    string contents = sr.ReadToEnd();
    using (StreamWriter sw = new StreamWriter("C:\\Work\\checksnapshot.properties"))
    {
        if (contents.Contains(args[0]))
        {
            sw.WriteLine("SASE= 1");
        }
        else
        {
            sw.WriteLine("SASE= 0");
        }
    }
}

//2
using (StreamReader sr = new StreamReader("C:\\Work\\analyzercommonsnapshot.txt")) ;
{
    string contents = sr.ReadToEnd();
    using (StreamWriter sw = new StreamWriter("C:\\Work\\checksnapshot.properties"))
    {
        if (contents.Contains(args[0]))
        {
            sw.WriteLine("Analyzer= 1");
        }
        else
        {
            sw.WriteLine("Analyzer= 0");
        }
    }
}

//3
using (StreamReader sr = new StreamReader("C:\\Work\\mobilesnapshot.txt")) ;
{
    string contents = sr.ReadToEnd();
    using (StreamWriter sw = new StreamWriter("C:\\Work\\checksnapshot.properties"))
    {
        if (contents.Contains(args[0]))
        {
            sw.WriteLine("mobile= 1");
        }
        else
        {
            sw.WriteLine("mobile= 0");
        }
    }
}

Answer 1

这样做怎么样，

new StreamWriter("C:\\Work\\checksnapshot.properties",true)

true表示文件存在时附加。

Answer 2

使用StreamWriter的正确构造函数：

new StreamWriter(someFile, true)

将打开someFile并附加。

Answer 3

使用FileStream代替StreamWriter：

using (FileStream fs = new FileStream("C:\\Work\\checksnapshot.properties",FileMode.OpenOrCreate,FileAccess.Append))
{
    StreamWriter writer = new StreamWriter(fs);
    writer.Write(whatever);
}

注意：我只在.NET 4中使用过它

Answer 4

我不知道为什么你的代码不起作用，但为什么不使用内置方法：

string contents = File.ReadAllText("C:\\Work\\labtoolssnapshot.txt");
string contents2 = File.ReadAllText("C:\\Work\\analyzercommonsnapshot.txt");
string contents3 = File.ReadAllText("C:\\Work\\mobilesnapshot.txt");
string outFile = "C:\\Work\\checksnapshot.properties";
//1 
if (contents.Contains(args[0]))
{
    File.WriteAllText(outFile,"SASE=1");
}
else
{
    File.WriteAllText(outFile,"SASE=0");
}
//2 
if (contents2.Contains(args[0]))
{
    File.AppendAllText(outFile,"Analyzer= 1");
}
else
{
    File.AppendAllText(outFile,"Analyzer= 0");
}

//3
if (contents3.Contains(args[0]))
{
    File.AppendAllText(outFile,"mobile= 1");
}
else
{
    File.AppendAllText(outFile,"mobile= 0");
}

或者，在一个更懒的代码中：

var contents = File.ReadAllText("C:\\Work\\labtoolssnapshot.txt");
var contents2 = File.ReadAllText("C:\\Work\\analyzercommonsnapshot.txt");
var contents3 = File.ReadAllText("C:\\Work\\mobilesnapshot.txt");
var outFile = "C:\\Work\\checksnapshot.properties";

File.WriteAllText(outfile, string.Format(
@"SASE= {0}
Analyzer= {1}
mobile= {2}
",
    contents.Contains(args[0]) ? "1" : "0",
    contents2.Contains(args[0]) ? "1" : "0",
    contents3.Contains(args[0]) ? "1" : "0"
    ));

使用streamwriter附加文本文件

4 个答案: