NULL 值同时通过 ZA34A6659BCEAE779F28185E75Z7 将 JSON 数据传递给 controller

Question

Trying to pass following JSON from View to Controller

{
    "allselected": false,
    "selectedIds": ["", "all"],
    "targetControl": "Studieniva",
    "targetSource": "studienivalist",
    "dependency": [{
        "name": "ShopNo",
        "selectedvalues": "311"
    }, {
        "name": "Institution",
        "selectedvalues": ["all", "UIO"]   // THIS IS COMING AS NULL AT CONTROLLER  . OCCURS ONLY WHEN MULTIPLE ITEMS UNDER dependency
    }]
}

Javascript code for sending request is like below (trying to make multiple requests at the same time and based on the response of each request loading some dropdowns )

        var targetcontrols_array = targetControl.split(',');
        var targetsource_array = targetSource.split(',');
        const arrOfPromises = targetcontrols_array.map(function(item, index) {
            var control_name = item;
            var source = targetsource_array[index];
            var request_data = JSON.stringify({ allselected: allselected_flag, selectedIds: selectedvalues, targetControl: control_name, targetSource: source, dependency: dependencyOptions });
            console.log("req:"+request_data); //SAMPLE JSON ADDED On TOP
            return new Promise((resolve) => {
                $.ajax({
                    url: action_url,
                    type: 'POST',
                    traditional: true,
                    async: false,
                    data: request_data,
                    contentType: "application/json; charset=utf-8",
                    dataType: 'json',
                    success: function (response) {
                       //process response
                    }
                })
            });
        });
        Promise.all(arrOfPromises); 

MVC controller action is like below

 [HttpPost]
 public JsonResult CascadingDropDown(DynamicFormSelectModel model)
 {
     model.dependency  values are not coming correctly . Observing that the value of SelectedValues is NULL in some cases
     ( OCCURS ONLY WHEN MULTIPLE ITEMS UNDER dependency )
 }

public class DynamicFormSelectModel
{
    public bool allselected { get; set; }
    public string[] selectedIds { set; get; }
    public string targetSource { set; get; }
    public string targetControl { set; get; }
    public List<DynamicFormDependencyOptions> dependency { set; get; }

}
public class DynamicFormDependencyOptions
{
    public string Name { get; set; }
    public string SelectedValues { get; set; }
}

While trying to read the request model.dependency values, sometimes getting NULL, even if values are passed from View (Example attached JSON passing 2 values "name": "Institution", "selectedvalues": ["all", "UIO"], but in controller i am getting NULL . OCCURS mostly WHEN MULTIPLE ITEMS are present under dependency property and no idea why its coming as NULL

Answer 1

    public class DynamicFormDependencyOptions
{
    public string Name { get; set; }
    public string SelectedValues { get; set; }
}

change it to

public class DynamicFormDependencyOptions
    {
        public string Name { get; set; }
        public string[] SelectedValues { get; set; }
    }

this code has the SelectedValues as string object but the data is in string Array form make SelectedValues a string Array and You'll get it.... and change your following code accordingly to parse the string array like you are doing for selectedIds .