C # Implementation retrieves sample code sharing that is case-insensitive and highlighted

This article mainly describes the C # retrieval of case-insensitive and highlight the details of the relevant information, the need for friends can refer to the following

C # retrieves case insensitive and highlights instances

Today, there is a question: how to highlight a case-insensitive keyword in a Web page

For example: text abcabcabcabcabcabca, keyword BC, in case-insensitive cases, a total of 6 matches.

The ABCABCABCABCABCABCA is displayed in the Web page.

Many people think of the replace function. However, the Replace function in C # does not solve the case of letters.

For example, bc,bc,bc,bc are searched, but not uniformly replaced by a single text

The above text to arrogant cow "Vancan a millet" article-"highlight the case-insensitive keyword--asp."

But his article is written in the ASP version, today I write a C # version, the following talk about the solution.

Workaround: Use IndexOf

IndexOf (String, Int32, StringComparison)

The index of the first occurrence of the specified string in the current string object.

Parameters

Value type: System. String to search for. startindex type: System. Int32 Search start location. Comparisontype type: System. StringComparison One of the enumeration values that specifies the search rule. (OrdinalIgnoreCase: The string is compared by using an ordinal collation and ignoring the case of the string being compared.) ）

Code

///<summary>///Highlight Find keywords. </summary>//<param name= "str" > Text. </param>//<param name= "keyword" > Keywords </param>//<returns> contains highlighted text.     </returns>///<remarks>//1, letters are case-insensitive.    2, CssClass name is called highlight.      </remarks> private String Highlightkeyword (string str, string keyword) {int index;      var startIndex = 0;      Const string highlightbegin = "<span class= ' highlight ' >";      Const string highlightend = "</span>"; var length = highlightbegin.length + keyword.      Length;      var lengthhighlight = length + highlightend.length; while (index = str. INDEXOF (keyword, startIndex, stringcomparison.ordinalignorecase)) >-1) {str = str. Insert (index, Highlightbegin).        Insert (index + length, highlightend);      StartIndex = index + lengthhighlight;    } return str; }