通过单击按钮从文本框复制内容

it is such that I have a textbox where I have some content in, and when I click the button clicks then it copies the content that is in textbox by itself, it should not be such that you have to run your mouse over to copy it. it just has to be like that when you click on the button that copies the it themselves.it is such that I have a textbox where I have s