StreamReader区分大小写

本文关键字：大小写 StreamReader | 更新日期: 2023-09-27 18:04:26

我的程序当前读取一个文本文件，并将其与文本框中的值进行比较，然后告诉我有多少匹配，这目前有效。

我的查询是区分大小写的。有没有办法让它不受大写或小写的影响?

下面是我的代码: 
if (!String.IsNullOrEmpty(CustodianEAddress.Text))
{
    for (AddressLength1 = 0; AddressLength1 < Length; AddressLength1++)
    {
        List<string> list1 = new List<string>();
        using (StreamReader reader = new StreamReader(FileLocation))
        {
            string line1;
            //max 500
            string[] LineArray1 = new string[500];
            while ((line1 = reader.ReadLine()) != null)
            {
                list1.Add(line1); // Add to list.
                if (line1.IndexOf(cust1[AddressLength1].ToString()) != -1)
                {
                    count1++;
                    LineArray1[count1] = line1;
                }
            }
            reader.Close();
            using (System.IO.StreamWriter filed = 
               new System.IO.StreamWriter(FileLocation, true))
            {
                filed.WriteLine("");
                filed.WriteLine("The email address " + 
             cust1[AddressLength1].ToString() + " was found " + count1 +
             " times within the recipient's inbox");
            }
            string count1a;
            count1a = count1.ToString();
        }
    }
}
else
{
    MessageBox.Show("Please Enter an Email Address");
}

基本上，我需要将cust1[AddressLength1]中的值与文本文件中数组中的值进行比较

StreamReader区分大小写

String.Compare()接受一个可选参数，该参数允许您指定是否应该区分大小写。

对发布的代码进行编辑

的Compare和Index都接受一个可选的枚举StringComparison。如果选择StringComparison。OrdinalIgnoreCase则忽略case

下面是不检查大小写的比较两个字符串的快速方法:

string a;
string b;
string.Compare(a, b, true);

这里的true是作为ignoreCase参数的值传递的，这意味着大写字母和小写字母将被比较，就好像它们都是相同的大小写。

编辑:

我已经清理了一些代码，并且还添加了比较函数。我在修改的地方添加了注释:

// Not needed: see below.  List<string> list1 = new List<string>();
using (StreamReader reader = new StreamReader(FileLocation))
{
    string line1;
    //max 500
    List<string> LineArray1 = new List<string>();
    while ((line1 = reader.ReadLine()) != null)
    {
        // list1.Add(line1); // Add to list.
        // By adding to the list, then searching it, you are searching the whole list for every single new line - you're searching through the same elements multiple times.
        if (string.Compare(line1, cust1[AddressLength1].ToString(), true) == 0)
        {
            // You can just use LineArray1.Count for this instead. count1++;
            LineArray1.Add(line1);
        }
    }
    // Not needed: using() takes care of this.  reader.Close();
    using (System.IO.StreamWriter filed =
        new System.IO.StreamWriter(FileLocation, true))
    {
        filed.WriteLine(); // You don't need an empty string for a newline.
        filed.WriteLine("The email address " +
        cust1[AddressLength1].ToString() + " was found " + LineArray1.Count +
        " times within the recipient's inbox");
    }
    string count1a;
    count1a = LineArray1.Count.ToString();
}

在比较时，您是否从文件中读取并不重要使用静态字符串比较函数:

public static int Compare(
    string strA,
    string strB,
    bool ignoreCase
)
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