解决方法
在github上的线程中有一个描述。引用(
https://github.com/ivaynberg/select2/issues/195#issuecomment-13489140通过
MortadaAK)，它允许您选择ctrl a上的所有内容
$(document).on("keypress",".select2-input",function(event){
if (event.ctrlKey || event.MetaKey) {
var id =$(this).parents("div[class*='select2-container']").attr("id").replace("s2id_","");
var element =$("#"+id);
if (event.which == 97){
var selected = [];
element.find("option").each(function(i,e){
selected[selected.length]=$(e).attr("value");
});
element.select2("val",selected);
} else if (event.which == 100){
element.select2("val","");
}
}
});
