查找一段字符串中相同元素出现的次数

 1   System.IO.StreamReader sr = new System.IO.StreamReader(aHtmlFilePath);
 2                 var htmlText = sr.ReadToEnd();
 3                 if (htmlText.Contains("img"))
 4                 {
 5                     string text = "";
 6                     int index = 0;
 7                     int count = 0;
 8                     int startindex, endindex;
 9                     while ((index=htmlText.IndexOf(text,index))!=-1)
10                     {
11                         count++;
12                         startindex = index + 12;
13                         endindex = htmlText.IndexOf("", index);
14                         pictures.Add(htmlText.Substring(startindex, endindex - startindex));
15                         index = index + text.Length;
16                     }
17                 }
18                 sr.Dispose();
19                 sr.Close();

 1   if (wWriteText.ToString().Contains("src"))
 2                 {
 3                     string text = "";
 4                     string bitmap = "Bitmap";
 5                     string result = string.Empty;
 6                     int index = 0;
 7                     int count = 0;
 8                     int startindex = 0;
 9                     if (wWriteText.ToString().Contains(bitmap))
10                         result = System.Text.RegularExpressions.Regex.Replace(wWriteText.ToString(), bitmap, "");
11                     wWriteText.Clear();
12                     wWriteText.Append(result);
13 
14                     while ((index = wWriteText.ToString().IndexOf(text, index)) != -1)
15                     {
16                         startindex = wWriteText.ToString().IndexOf(text,index);
17                         wWriteText.Insert(startindex, pictures[count].ToString());
18                         index = index + text.Length + pictures[count].Length;
19                         count++;
20                     }
21                 }

 1   if (wWriteText.ToString().Contains("src"))
 2                 {
 3                     string text = "";
 4                     string bitmap = "Bitmap";
 5                     string result = string.Empty;
 6                     int index = 0;
 7                     int count = 0;
 8                     int startindex = 0;
 9                     if (wWriteText.ToString().Contains(bitmap))
10                         result = System.Text.RegularExpressions.Regex.Replace(wWriteText.ToString(), bitmap, "");
11                     wWriteText.Clear();
12                     wWriteText.Append(result);
13 
14                     while ((index = wWriteText.ToString().IndexOf(text, index)) != -1)
15                     {
16                         startindex = wWriteText.ToString().IndexOf(text,index);
17                         wWriteText.Insert(startindex, pictures[count].ToString());
18                         index = index + text.Length + pictures[count].Length;
19                         count++;
20                         if (pictures.Count == 1)
21                             break;
22                     }
23                 }