点击按钮实现复制指定文本

<script>
function copyMyText() {
     //select the element with the id "copyMe", must be a text box
     var textToCopy = document.getElementById("copyMe");
     //select the text in the text box
     textToCopy.select();
     //copy the text to the clipboard
     document.execCommand("copy");
}
</script>

<script>
function CopyClassText(){
     //select the element with ID = "CopyMeID", can be a div, p, or a span, possibly others
     var textToCopy = document.getElementById("CopyMeID");
 
     //you can target the same element using querySelector() as well
     //example below:
     //var textToCopy = document.querySelector('.CopyMeClass');
 
     //check and see if the user had a text selection range
     var currentRange;
     if(document.getSelection().rangeCount > 0)
     ;{
          //the user has a text selection range, store it
          currentRange = document.getSelection().getRangeAt(0);
          //remove the current selection
          window.getSelection().removeRange(currentRange);
     }
     else
     {
          //they didn't have anything selected
          currentRange = false;
     }
 
     //create a selection range
     var CopyRange = document.createRange();
     //choose the element we want to select the text of
     CopyRange.selectNode(textToCopy);
     //select the text inside the range
     window.getSelection().addRange(CopyRange);
     //copy the text to the clipboard
     document.execCommand("copy");
 
     //remove our selection range
     window.getSelection().removeRange(CopyRange);
 
     //return the old selection range
     if(currentRange)
     {
          window.getSelection().addRange(currentRange);
     }
}
</script>

<script>
function AdvancedCopy(){
     //the text that is to be copied to the clipboard
     var theText = '这段文字会被复制到剪贴板';
 
     //create our hidden div element
     var hiddenCopy = document.createElement('div');
     //set the innerHTML of the div
     hiddenCopy.innerHTML = theText;
     //set the position to be absolute and off the screen
     hiddenCopy.style.position = 'absolute';
     hiddenCopy.style.left = '-9999px';
 
     //check and see if the user had a text selection range
     var currentRange;
     if(document.getSelection().rangeCount > 0)
     {
          //the user has a text selection range, store it
          currentRange = document.getSelection().getRangeAt(0);
          //remove the current selection
          window.getSelection().removeRange(currentRange);
     }
     else
     {
          //they didn't have anything selected
          currentRange = false;
     }
 
     //append the div to the body
     document.body.appendChild(hiddenCopy);
     //create a selection range
     var CopyRange = document.createRange();
     //set the copy range to be the hidden div
     CopyRange.selectNode(hiddenCopy);
     //add the copy range
     window.getSelection().addRange(CopyRange);
 
     //since not all browsers support this, use a try block
     try
     {
          //copy the text
          document.execCommand('copy');
     }
     catch(err)
     {
          window.alert("Your Browser Doesn't support this! Error : " + err);
     }
     //remove the selection range (Chrome throws a warning if we don't.)
     window.getSelection().removeRange(CopyRange);
     //remove the hidden div
     document.body.removeChild(hiddenCopy);
 
     //return the old selection range
     if(currentRange)
     {
          window.getSelection().addRange(currentRange);
     }
}
</script>