Json post到asp.net核心剃须刀页面模型返回空
Json post到asp.net核心剃须刀页面模型返回空
提问于 2020-10-22 03:14:50
尝试了大量的解决方案，并在网上修复，但没有进展，做了调查研究，我需要你们的帮助，伙计们。
这是我的Js脚本，用于将学生成绩推送到页面模型，当我检查学生成绩时，它有值。
<script>
if (btnTakeScore) {
btnTakeScore.onclick = function (e) {
e.preventDefault();
var rows = document.querySelectorAll('tbody tr');
let studentScores = [];
for (let i = 0; i < rows.length; i++) {
let studentId = rows[i].getAttribute('studentId');
studentScores.push({
studentId: studentId,
sessionId: cboSession.value,
termId: cboTerms.value,
classId: cboClass.value,
subjectScores: []
})
let tds = rows[i].querySelectorAll('td input[type="number"]');
for (let j = 0; j < tds.length; j++) {
// Simulate missing score instead of a 0;
let ctrl = tds[j];
if (ctrl.value !== '') {
studentScores[i].subjectScores.push({
studentId: studentId,
subjectId: tds[j].getAttribute('subjectId'),
score: ctrl.value,
scoreTypeId: cboScoreType.value
});
}
}
}
// call server here to post the data
//const serverUrl = 'https://localhost:44301/api/SaveStudentScores';
const serverUrl = '@Url.Page("/Teacher/StudentScore")?handler=SaveScore';
let r = new XMLHttpRequest();
r.open('post', serverUrl);
r.setRequestHeader('content-Type', 'application/json');
r.setRequestHeader("XSRF-TOKEN",
$('input:hidden[name="__RequestVerificationToken"]').val());
r.send(JSON.stringify(studentScores));
r.onload = function () {
if (r.status === 200) {
var res = JSON.parse(this.responseText);
if (res.status === true) {
alert(res.message);
// clear the fields.
var inputs = document.querySelectorAll('table#scoreEntry input[type="number"]');
inputs.forEach(d => d.value = '0'); // reset the scores to Zero
}
}
}
}
}
<script>这是我的PageModel OnPost。当它来到这里时，分数值变为空。
public async Task<JsonResult> OnPostSaveScore([FromBody]IEnumerable<StudentScoreContainer> scores)
{
try
{
// Code to push date to the database
}
return new JsonResult(new { status = true, messsage = "Student(s) score saved!" });
}
catch (Exception ex)
{
return new JsonResult(new { status = false, message = ex.Message });
}
}
public struct StudentScoreContainer
{
public int studentId { get; set; }
public int classId { get; set; }
public int sessionId { get; set; }
public int termId { get; set; }
public int scoreTypeId { get; set; }
public IEnumerable<SubjectScoreContainer> subjectScores { get; set; }
}
public struct SubjectScoreContainer
{
public int studentId { get; set; }
public int subjectId { get; set; }
public int score { get; set; }
}这是我的Html代码
<div class="card-body">
<div class="row">
<div class="col-sm-2">
<div class="form-group">
<label>Class Room<span class="text-danger">*
</span></label>
<select id="classRoom" class="select" form="searchForm" required="required" asp-items="@(new SelectList(Model.Classess, "Class.Id","Class.Name"))">
<option value="">Select ClassRoom</option>
</select>
</div>
</div>
<div class="col-sm-2">
<div class="form-group">
<label>Session<span class="text-danger">*</span></label>
<select id="session" class="select" required="required" asp-items="@(new SelectList(Model.Sessions, "Id","Name"))">
<option value="">Select Session</option>
</select>
</div>
</div>
<div class="col-sm-2">
<div class="form-group">
<label>Term<span class="text-danger">*</span></label>
<select id="term" class="select" required="required" asp-items="@(new SelectList(Model.Terms, "Id","Name"))">
<option value="">Select Term</option>
</select>
</div>
</div>
<div class="col-sm-2">
<div class="form-group">
<label>Score Types<span class="text-danger">*</span></label>
<select id="cboScoreType" class="select" required="required" asp-items="@(new SelectList(Model.ScoreTypes, "Id","Name"))">
<option value="">Select ScoreType</option>
</select>
</div>
</div>
<div class="col-md-3">
<label></label>
<p></p>
<button id="btnSearch" type="submit" class="btn btn-success btn-block"> Search </button>
</div>
</div>
<div class="row">
<div class="col-lg-12">
<div class="table-responsive">
<table class="table table-striped custom-table table-nowrap mb-0" id="studentList">
<thead>
<tr>
<th>Student</th>
@foreach (var s in Model.SubjectsByTeacher)
{
<th style="text-align:center">@s.Subject.Name</th>
}
</tr>
</thead>
<tbody>
@foreach (var student in Model.Students)
{
<tr studentId="@student.StudentID">
<td>@(student.FirstName.Trim() + " " + student.LastName.Trim())</td>
@foreach (var subject in Model.SubjectsByTeacher)
{
<td style="text-align:center"><input type="number" min="0" max="100" class="form-control" studentId="@student.StudentID" subjectId="@subject.Subject.Id" /></td>
}
</tr>
}
</tbody>
</table>
<br />
</div>
</div>
<div>
</div>
</div>
<div class="row">
<div class="col-md-12">
<div class="form-group">
<button id="btnTakeScore" class="btn btn-primary">
<i class="fa fa-pen"></i> <b>Take Scores</b>
</button>
</div>
</div>
</div>
</div>我非常感谢你的帮助。
回答 1
Stack Overflow用户
回答已采纳
发布于 2020-10-23 10:44:20
根据js和剃刀页面代码，我发现您直接读取getAttribute值并将其发布到页面方法中。
因为studentId和其他属性都是int类型，但是从html代码中得到的值是字符串。这就是为什么页面模型不能很好地绑定值的原因。
我建议您可以在js中将rows[i].getAttribute('studentId')转换为int。
如下所示：
因为我没有完整的js代码和pagemodel类，所以我只创建一个测试js模型来测试它。
您可以尝试按照下面的代码替换您所拥有的js代码。
studentScores：
studentScores.push({
studentId: +studentId,
sessionId: +cboSession.value,
termId: +cboTerms.value,
classId: +cboClass.value,
subjectScores: []
})subjectScores：
studentScores[i].subjectScores.push({
studentId: +studentId,
subjectId: +tds[j].getAttribute('subjectId'),
score: +ctrl.value,
scoreTypeId: +cboScoreType.value
});作为@Joseph的评论，我们也可以使用NewtonsoftJson而不是System.Text.Json来报道这个问题。
更多细节，请参阅以下代码：
从url下面安装Microsoft.AspNetCore.Mvc.NewtonsoftJson：
https://www.nuget.org/packages/Microsoft.AspNetCore.Mvc.NewtonsoftJson
将以下代码添加到startup.cs配置服务方法中：
services.AddRazorPages().AddNewtonsoftJson();页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/64474750
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