Javascriptselection的兼容性写法介绍_基础知识

var txt = "";
if (window.getSelection) {
txt = window.getSelection();
} else if (window.document.getSelection) {
txt = window.document.getSelection();
} else if (window.document.selection) {
txt = window.document.selection.createRange().text;
}
return txt;
}