这可能与您正在寻找的内容类似，它不强制设置类别，但不允许用户提交新帖子，除非至少选择了一个类别

此解决方案需要jQuery，但只需稍加修改即可移植到普通JavaScript

//intercept the "update" or "publish" button
$("#post").submit(function(e){
    //grab the GET query (just to be sure we are editing a post, not a page)   
    var split = location.search.replace(\'?\', \'\').split(\'&\').map(function(val){
        return val.split(\'=\');
    });


    //check GET value for "post" and "edit" variables
    if(split[0][0] == \'post\' && split[1][0] == \'action\' && split[1][1] == \'edit\' ){

        //get the category checkboxes
        var categories = $(\'input[name=post_category\\\\[\\\\]]\');

        //flag to check if at least one category is selected
        var atLeastOneChecked = false;

        //iterate over the category checkboxes
        for (var i = 0; i < categories.length; i++) {

            //if we find one selected and is not the 0 cat let return true and have 
            //the form submitted
            if(categories[i].checked == true && !(categories[i].value == 0)){
                return true;
            }
        }

        //else, let your users know they must select a category
        alert("You Must Select at least one of your visible categories");
        return false;
    }
    return true;
});

没有上下文很难说出你在说什么，但听起来你只是想在默认情况下将新帖子分配到特定类别？

如果这是真的，那么只需转到“设置>>编写”，并将“默认帖子类别”更改为创建新帖子时希望选择的任何类别。

如果这不是你想做的，那么我想我们需要更多的背景，更好地描述你想做什么。