在数组中查找文本

Question

我正在将例程从 C++ 移植到 C#，但很难理解移植失败的原因：

我有一个字符串数组，其中包含我正在尝试删除的内容。

    string[] aryLines = File.ReadAllLines(mstrFilename);

数组包含以下内容：

aryLines = new[]
{
    "<?xml version=\"1.0\" encoding=\"utf-8\"?>",
    "<!--",
    "",
    "  File:\t\tuif.xml, User Interface",
    "  Notes:\tThis file contains the application layout and includes",
    "\t\tfor other files defining the application look and functionality.",
    "",
    "  Node:\t\tuif, Root container node",
    "  Attributes:\tid\t\t: Unique node identifier",
    "\t\tcameras\t\t: Initial camera set-up",
    " \t\tcolor_bg\t: Application background colour:",
    "\t\t\t\t\tAlpha, Red, Green, Blue",
    "\t\theight\t\t: Height of the application container",
    "\t\twidth\t\t: Width of the appplication container\t\t",
    "",
    "  Node:\t\tinclude, Includes another XML file",
    "  Attributes:\tname\t\t: Encoded path to XML file to include",
    "",
    "  History:\t2017/09/11 Created by Simon Platten",
    "// -->"
};

我有一个方法应该删除 cmets，找到第一次出现的 <!-- 和匹配的 -->，然后它将删除中间的所有内容。问题是，虽然它找到了<!--，但它没有找到-->，我不明白为什么。

private static readonly string msrostrCmtClose = "-->";
private static readonly string msrostrCmtOpen = "<!--";

int intOpen = 0;
while((intOpen = Array.IndexOf(aryLines, msrostrCmtOpen, intOpen)) >= 0) 
{
    //Opening marker located, look for closing marker   
    int intClose = Array.IndexOf(aryLines, msrostrCmtClose, intOpen);

    if ( intClose < intOpen ) 
    {
        //Shouldn't get here!
        continue;
    }

    Console.WriteLine(intOpen);
}

上面的套路不完整，但是在调试器中看intClose总是-1，为什么？

Answer 1

这里的问题是Array.IndexOf 将每个元素与您要查找的内容进行比较，除了您要查找的内容实际上不在数组中。数组中的内容是 // --> 而不仅仅是 -->。

你可以做一个像这样的简单函数：

private int IndexOfInArray(string[] array, string elemToFind, int startIndex = 0)
{
    for (int i = startIndex; i < array.Length; i++)
    {
        if (array[i].Contains(elemToFind))
            return i;
    }

    return -1;
}

然后像这样使用它：

int intOpen = 0;
while((intOpen = IndexOfInArray(aryLines, msrostrCmtOpen, intOpen)) >= 0 ) 
{
    //Opening marker located, look for closing marker   
    int intClose = IndexOfInArray(aryLines, msrostrCmtClose, intOpen);
    if (intClose < intOpen) 
    {
        //Shouldn't get here!
        continue;
    }

    Console.WriteLine(intOpen);
}

您可能必须将intOpen 设置为intClose 或只设置intOpen++ 才能永远得到相同的结果。

Answer 2

我现在已经解决了这个问题，感谢 cmets 中的建议，新的解析器看起来像这样：

    string strXML = File.ReadAllText(mstrFilename);

    int intOpen = 0;
    while( (intOpen = strXML.IndexOf(msrostrCmtOpen, intOpen)) >= 0 ) {
    //Opening marker located, look for closing marker   
            int intClose = strXML.IndexOf(msrostrCmtClose, intOpen);

            if ( intClose < intOpen ) {
    //Shouldn't get here!
                continue;
            }
            Console.WriteLine(intOpen);
        }