after clicking on this method, there is no selection condition box like iOS. Why is this so? There is no problem with ios

function uploadBox(flag){

            if(mui.os.plus || mui.os.android || mui.os.iphone ){
                debugger
                var a = [{
                    title: ""
                }, {
                    title: ""
                }];
                
            plus.nativeUI.actionSheet({
                    title: "",
                    cancel: "",
                    buttons: a
                }, function(b) {
                    switch (b.index) {
                        case 0:
                            break;
                        case 1:
                            getImage(flag);
                            break;
                        case 2:
                            galleryImg(flag);
                            break;
                        default:
                            break;
                    }
                })
            }
        }