container 接近焦点会发生变化的问题

//自定义复制函数  
function copy() {
    var clipboard = new ClipboardJS('#模态对话框内复制按钮的id', {
        container: document.getElementById('模态对话框id'),
        text: function (trigger) {  
            return '需要被复制的字符串';
        }
    });

    clipboard.on('success', function (e) {
        e.clearSelection();
        document.getElementById("msg").innerHTML = "复制成功";
    });

    clipboard.on('error', function (e) {
        document.getElementById("msg").innerHTML = "复制失败";
    });
}