Angular 从 c# 接收到 StatusCode 对象时意外触发 catchError

Question

我有一个正在 C# 后端工作的 API 调用，但 Angular 前端似乎将 C# 回复视为错误。请注意，对象的文本是 'comment added'，表示已发回 200 OK 响应。为什么会触发catchError函数？

C# 方法：

[HttpPost("AddComments")]
public ActionResult<string> AddComment(BillingComments b)
{
    try
    {
        return StatusCode(200, "comment added");
    }
    catch (Exception e)
    {
        return StatusCode(500, "error adding comment");
    }
}

Angular方法：

submitComment(newComment: BillingComments): any {
    return this.http.post('/api/BillingLg/AddComments', newComment)
        .pipe(catchError(this.appSvc.handleError<string>('submitComment', 'comment submitting err')));
}

appSvc.handleError返回的错误：

Service error: submitComment failed Msg: Http failure during parsing for http://localhost:49975/api/BillingLg/AddCommentsStatus: 200Detail: {"error":{},"text":"comment added"}Text: OK & return type specified (failed gracefully)

Answer 1

Angular 默认解析来自 API 的响应到对象，因此默认情况下，它期望 JSON 字符串是 return 来自 [=19] =].

所以你有两个选择，要么 return a JSON 而不是字符串（推荐），比如

return StatusCode(200, "{\"status\": \"comment added\"}");

或者您可以让 HttpClient 期望字符串被 returned:

this.http.post('/api/BillingLg/AddComments', newComment, {responseType: 'text'})
    .pipe(catchError(this.appSvc.handleError<string>('submitComment', 'comment submitting err')));

Angular 从 c# 接收到 StatusCode 对象时意外触发 catchError

Angular catchError firing unexpectedly when received StatusCode object from c#

c#

post

api-design

angular