为了更好地理解tabindex元素是如何工作的，完成公认的回答:

The tabindex global attribute is an integer indicating if the element can take input focus (is focusable), if it should participate to sequential keyboard navigation, and if so, at what position. It can take several values:   -a negative value means that the element should be focusable, but should not be reachable via sequential keyboard navigation;   -0 means that the element should be focusable and reachable via sequential keyboard navigation, but its relative order is defined by the platform convention;   -a positive value means should be focusable and reachable via sequential keyboard navigation; its relative order is defined by the value of the attribute: the sequential follow the increasing number of the tabindex. If several elements share the same tabindex, their relative order follows their relative position in the document.

来自:Mozilla开发人员网络

如果你使用stisla并使用firemodal:

$('#modal-create-promo').click(()=>{
    setTimeout(()=>{
        $('#fire-modal-1').removeAttr('tabindex');
    });
});

    $("#modal-create-promo").fireModal({
    ...
});

这是我的工作

如果你的iPad键盘在点击select2输入时隐藏了引导模式，你可以通过在select2输入初始化后添加以下规则来解决这个问题:

if (navigator.userAgent.match(/iPhone|iPad|iPod/i)) {
   var styleEl = document.createElement('style'), styleSheet;
   document.head.appendChild(styleEl);
   styleSheet = styleEl.sheet;
   styleSheet.insertRule(".modal { position:absolute; bottom:auto; }", 0);
   document.body.scrollTop = 0; // Only for Safari
}

摘自https://github.com/angular-ui/bootstrap/issues/1812#issuecomment-135119475

编辑:如果你的选项没有正确显示，你需要在初始化select2时使用dropdownParent属性:

$(".select2").select2({
    dropdownParent: $("#YOURMODALID")
});

祝你好运

基于@pymarco的答案，我写了这个解决方案，它不是完美的，但解决了select2焦点问题，并保持制表符序列在模态内工作

    $.fn.modal.Constructor.prototype.enforceFocus = function () {
        $(document)
        .off('focusin.bs.modal') // guard against infinite focus loop
        .on('focusin.bs.modal', $.proxy(function (e) {
            if (this.$element[0] !== e.target && !this.$element.has(e.target).length && !$(e.target).closest('.select2-dropdown').length) {
                this.$element.trigger('focus')
            }
        }, this))
    }

$("#IlceId").select2({
    allowClear: true,
    multiple: false,
    dropdownParent: $("#IlceId").parent(),
    escapeMarkup: function (m) {
        return m;
    },
});

这段代码正在工作。谢谢你！

.select2-close-mask{
    z-index: 2099;
}
.select2-dropdown{
    z-index: 3051;
}

这是我使用select2 4.0.0的解决方案。只需要覆盖select2.css导入下面的css。 请确保z指数大于对话框或模态。我只是在默认值上加了2000。因为我的对话框的z-index是1000。