Question

如何在字符串中的字符前找到10个字符？例如;

string abcd = "asdsdasdasdasdasdasasdasasdssXsdasdsadas";

如何在X之前找到10个字符？

Answer 1

string searchWithinThis = "asdsdasdasdasdasdasasdasasdssXsdasdsadas";
string searchForThis = "X";

int firstCharacter = searchWithinThis.IndexOf(searchForThis);

if (firstCharacter < 0) {
  Console.WriteLine("Character {0} not found", searchForThis);
} else {
  Console.WriteLine("First occurrence: {0}", firstCharacter);
}

如果你想要X之前的10个字符，包括X：

int tenCharactersBefore = Math.Max(firstCharacter - 10, 0);

string result = searchWithinThis.SubString(tenCharactersBefore, 10)
Console.WriteLine("The ten characters before are {0}", result);

如果你想要X之前的10个字符的字符串，不包括X：

int tenCharactersBefore = Math.Max(firstCharacter - 11, 0);

string result = searchWithinThis.SubString(tenCharactersBefore, 10)
Console.WriteLine("The ten characters before are {0}", result);

如果您只想要X之前10个字符的字符：

int tenCharactersBefore = Math.Max(firstCharacter - 10, 0);

string result = searchWithinThis.SubString(tenCharactersBefore, 1)
Console.WriteLine("The ten characters before are {0}", result);

Answer 2

您可以使用String.Substring和String.IndexOf等方法;

string abcd = "asdsdasdasdasdasdasasdasasdssXsdasdsadas";
Console.WriteLine(abcd.Substring(abcd.IndexOf("X") - 10, 10));

基本，你得到X的索引并用该位置减去10，之后，你得到从该位置开始的子串并得到10之后的人物。

当然，您应首先检查X的索引是否大于10。因为如果它小于10，你应该检查;

if(abcd.IndexOf("X") < 10)
    Console.WriteLine(abcd.Substring(0, abcd.IndexOf("X")));
else
    Console.WriteLine(abcd.Substring(abcd.IndexOf("X") - 10, 10));

输出将是;

asdasasdss

这是DEMO。

Answer 3

 string result=string.Empty;
 string abcd = "asdsdasdasdasdasdasasdasasdssXsdasdsadas";

    int indexOfStringToSearch = abcd.IndexOf("X");
    if(indexOfStringToSearch!=-1)
      { 
        if(indexOfStringToSearch -10 >0)
            result = abcd.Substring(indexOfStringToSearch-10,10);
        else
            result = abcd.Substring(0,indexOfStringToSearch-1);
     }

Answer 4

如果只有一个'X'字符：

试试这个：

string abcd = "asdsdasdasdasdasdasasdasasdssXsdasdsadas";
string[] words = s.Split('X');
Console.WriteLine(words[0].substring(words[0].length-10,10));

或多个

string abcd = "asdsdasdasdasdasdasasdasasdssXsdasdsadas";
string[] words = s.Split('X');
for(int i=0;i<words.length; i++)
{
   Console.WriteLine(word[i].substring(word[i].length-10,10));
}

在角色前找到10个字符

4 个答案: