利用Visual Basic.NET编写一个能够模拟WORD程序中“查找并替换”功能的程序。

程序功能解释：用户先在某一文本框中输入一篇短文的内容，然后单击某一命令按钮时，将显示另一窗口，让用户输入“要查找的内容”和“要替换成的内容”，程序能根据用户输入的“要查找的内容”和“要替换成的内容”从已输入的短文内容中进行查找，当找到时，被找到的内容以反相显示（即呈选中状态），然后出现提示对话框，询问用户是否替换，如果回答“是”，则对其进行替换；如果回答“否”，则不替换。重复以上过程，直到全部内容查找完毕。

查找和替换工作完成时，将已找到的次数和替换的次数显示出来-Written in Visual Basic.NET one can simulate WORD program " Find and replace"　function of the program. The program features explained: when the user first in the contents of a text box, enter an essay, and then click a command button will display another window, allowing users to input' re looking for and was asked to replace the content , the program can be entered by the user to find content and was asked to be replaced by the " have entered the short to find, when found, was found to reverse video (ie, was selected ), and then prompted the dialog box asks the user whether to replace, if the answer is " yes" , then replace it　If the answer is " No" , not replace. Repeat the above process until the entire contents of the lookup is completed. Find and replace the work is completed, it will find the number and the number of substitutions