根据HTML规范,HTML中的select标签没有readonly属性,只有disabled属性。所以如果你想让用户不改变下拉菜单,你必须使用disabled。

唯一的问题是禁用的HTML表单输入不会包含在POST / get数据中。

什么是最好的方法来模拟一个选择标签的只读属性,仍然得到POST数据?


当前回答

摘自https://stackoverflow.com/a/71086058/18183749

如果你不能使用'disabled'属性(因为它会擦除值的 input at POST),并注意到html属性'readonly'只工作 在文本区域和一些输入(文本,密码,搜索,据我所见), 最后,如果你不想重复你所有的 您可能会发现,带有隐藏输入逻辑的选择、复选框和单选 下面的函数或任何他的内部逻辑你喜欢:

addReadOnlyToFormElements = function (idElement) {
    
        // html readonly don't work on input of type checkbox and radio, neither on select. So, a safe trick is to disable the non-selected items
        $('#' + idElement + ' select>option:not([selected])').prop('disabled',true);
    
        // and, on the selected ones, to mimic readOnly appearance
        $('#' + idElement + ' select').css('background-color','#eee');
    }

没有什么比删除这些只读更容易的了

removeReadOnlyFromFormElements = function (idElement) {

    // Remove the disabled attribut on non-selected 
    $('#' + idElement + ' select>option:not([selected])').prop('disabled',false);

    // Remove readOnly appearance on selected ones
    $('#' + idElement + ' select').css('background-color','');
}

其他回答

根据格兰特·瓦格纳的建议;下面是一个jQuery代码片段,它使用处理函数而不是直接使用onXXX属性:

var readonlySelect = function(selector, makeReadonly) {

    $(selector).filter("select").each(function(i){
        var select = $(this);

        //remove any existing readonly handler
        if(this.readonlyFn) select.unbind("change", this.readonlyFn);
        if(this.readonlyIndex) this.readonlyIndex = null;

        if(makeReadonly) {
            this.readonlyIndex = this.selectedIndex;
            this.readonlyFn = function(){
                this.selectedIndex = this.readonlyIndex;
            };
            select.bind("change", this.readonlyFn);
        }
    });

};
    var selectedOpt;//initialize var
    var newIdForHidden;//initialize var
    $('.disabledOnEdit').focusin(function(){
        selectedOpt = $(this).find(":selected").val();
        newIdForHidden = $(this).attr('id')+'Hidden';
        //alert(selectedOpt+','+newIdForHidden);
        $(this).append('');
        $(this).find('input.hiddenSelectedOpt').attr('id',newIdForHidden).val(selectedOpt);
    });
    $('.disabledOnEdit').focusout(function(){
        var oldSelectedValue=$(this).find('input.hiddenSelectedOpt').val();
        $(this).val(oldSelectedValue);
    });

当您计划将选择设置为只读时,请将选择设置为禁用,然后在提交表单之前删除禁用属性。

// global variable to store original event/handler for save button
var form_save_button_func = null;

// function to get jQuery object for save button
function get_form_button_by_id(button_id) {
    return jQuery("input[type=button]#"+button_id);
}

// alter value of disabled element
function set_disabled_elem_value(elem_id, value)  {
    jQuery("#"+elem_id).removeAttr("disabled");
    jQuery("#"+elem_id).val(value);
    jQuery("#"+elem_id).attr('disabled','disabled');
}

function set_form_bottom_button_save_custom_code_generic(msg) {
    // save original event/handler that was either declared
    // through javascript or html onclick attribute
    // in a global variable
    form_save_button_func = get_form_button_by_id('BtnSave').prop('onclick'); // jQuery 1.6
    //form_save_button_func = get_form_button_by_id('BtnSave').prop('onclick'); // jQuery 1.7

    // unbind original event/handler (can use any of following statements below)
    get_form_button_by_value('BtnSave').unbind('click');
    get_form_button_by_value('BtnSave').removeAttr('onclick');

    // alternate save code which also calls original event/handler stored in global variable
    get_form_button_by_value('BtnSave').click(function(event){
        event.preventDefault();
        var confirm_result = confirm(msg);
        if (confirm_result) {
            if (jQuery("form.anyForm").find('input[type=text], textarea, select').filter(".disabled-form-elem").length > 0) {
                jQuery("form.anyForm").find('input[type=text], textarea, select').filter(".disabled-form-elem").removeAttr("disabled");
            }

            // disallow further editing of fields once save operation is underway
            // by making them readonly
            // you can also disallow form editing by showing a large transparent
            // div over form such as loading animation with "Saving" message text
            jQuery("form.anyForm").find('input[type=text], textarea, select').attr('ReadOnly','True');

            // now execute original event/handler
            form_save_button_func();
        }
    });
}

$(document).ready(function() {
    // if you want to define save button code in javascript then define it now

    // code below for record update
    set_form_bottom_button_save_custom_code_generic("Do you really want to update this record?");
    // code below for new record
    //set_form_bottom_button_save_custom_code_generic("Do you really want to create this new record?");

    // start disabling elements on form load by also adding a class to identify disabled elements
    jQuery("input[type=text]#phone").addClass('disabled-form-elem').attr('disabled','disabled');
    jQuery("input[type=text]#fax").addClass('disabled-form-elem').attr('disabled','disabled');
    jQuery("select#country").addClass('disabled-form-elem').attr('disabled','disabled');
    jQuery("textarea#address").addClass('disabled-form-elem').attr('disabled','disabled');

    set_disabled_elem_value('phone', '123121231');
    set_disabled_elem_value('fax', '123123123');
    set_disabled_elem_value('country', 'Pakistan');
    set_disabled_elem_value('address', 'address');

}); // end of $(document).ready function

摘自https://stackoverflow.com/a/71086058/18183749

如果你不能使用'disabled'属性(因为它会擦除值的 input at POST),并注意到html属性'readonly'只工作 在文本区域和一些输入(文本,密码,搜索,据我所见), 最后,如果你不想重复你所有的 您可能会发现,带有隐藏输入逻辑的选择、复选框和单选 下面的函数或任何他的内部逻辑你喜欢:

addReadOnlyToFormElements = function (idElement) {
    
        // html readonly don't work on input of type checkbox and radio, neither on select. So, a safe trick is to disable the non-selected items
        $('#' + idElement + ' select>option:not([selected])').prop('disabled',true);
    
        // and, on the selected ones, to mimic readOnly appearance
        $('#' + idElement + ' select').css('background-color','#eee');
    }

没有什么比删除这些只读更容易的了

removeReadOnlyFromFormElements = function (idElement) {

    // Remove the disabled attribut on non-selected 
    $('#' + idElement + ' select>option:not([selected])').prop('disabled',false);

    // Remove readOnly appearance on selected ones
    $('#' + idElement + ' select').css('background-color','');
}

我知道这不会帮助每个人(如果你只是客户端),但会帮助一些全栈和控制后端以及前端的人。

如果用户没有编辑字段的特权,我只返回下拉列表的当前选择。

以下是我的后端控制器:

        #region Prepare Action Priviledges
        editAuditVM.ExtAuditEditRoleMatrixVM = new ExtAuditEditRoleMatrixVM
        {
            CanEditAcn = _extAuditEditRoleMatrixHelper.CanEditAcn(user, audit),
            CanEditSensitiveDesignation = _extAuditEditRoleMatrixHelper.CanEditSensitiveDesignation(user, audit),
            CanEditTitle = _extAuditEditRoleMatrixHelper.CanEditTitle(),
            CanEditAuditScope = _extAuditEditRoleMatrixHelper.CanEditAuditScope(user, audit)
        };
        #endregion


        #region Prepare SelectLists for Drop Downs
        #region AuditScope List
        IQueryable<SelectListItem> auditScopes = _auditTypesRepo.AuditTypes
            .Where(at => at.AuditTypeClassCode.ToLower() == "e")
            .Select(at => new SelectListItem
            { Text = at.AuditTypeText, Value = at.AuditTypeID.ToString() });
        // Cannot make a select readonly on client side.
        //  So only return currently selected option.
        if (!editAuditVM.ExtAuditEditRoleMatrixVM.CanEditAuditScope)
        {
            auditScopes = auditScopes
                .Where(ascopeId => ascopeId.Value == editAuditVM.ExternalAudit.AuditTypeID.ToString());
        }
        #endregion
        #endregion