从Asp.net Core读取数据到Angular 7

Question

Good day,

I've been doing some self study in Angular 7 and Asp.net core web api.

And now i want to read the result from asp.net core and show in in Angular 7.

This is the code from Asp.net Core

[HttpPost("DataCorrection")]
        public  IActionResult DataCorrection([FromBody] DataCorrectionDto data)
        {
            try
            {
                var request =  Request;
                var values =   _dataCorrection.GetDateRange(data.StartDate, data.EndDate);

                return Ok(values);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.WriteLine(ex.StackTrace);
                throw ex;
            }
        }

The method GetDateRange returns a List of DataCorrection Model

And this is my angular code

     import { Component, OnInit } from '@angular/core';
import { FormGroup, FormControl,  } from '@angular/forms';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-data-correction',
  templateUrl: './data-correction.component.html',
  styleUrls: ['./data-correction.component.css']
})
export class DataCorrectionComponent implements OnInit {
  list: any[];
  selectedDate = new Date();
  form = new FormGroup({
    StartDate: new FormControl(),
    EndDate: new FormControl()
  });

  constructor(private http: HttpClient) { }
  ngOnInit() {
  }

  onSubmit() {
    this.http.post('http://localhost:5000/api/DataCorrection/DataCorrection', this.form.value)
    .toPromise()
    .then(res => {
      this.list = res as any[];
      console.log('Called');
      });
  }

}

And this is the Html Code

<form [formGroup]="form" (ngSubmit)="onSubmit()">
    <!-- <input formControlName="first" [(ngModel)]="value"> -->
    <mat-form-field>
      <input matInput formControlName="StartDate"  [matDatepicker]="StartDate" placeholder="Start date">
      <mat-datepicker-toggle matSuffix [for]="StartDate"></mat-datepicker-toggle>
      <mat-datepicker #StartDate  ></mat-datepicker>
    </mat-form-field>

    <mat-form-field>
        <input matInput formControlName="EndDate"   [matDatepicker]="EndDate" placeholder="End date">
        <mat-datepicker-toggle matSuffix [for]="EndDate"></mat-datepicker-toggle>
        <mat-datepicker #EndDate  ></mat-datepicker>
      </mat-form-field>
    <div class="form-group">
      <button class="btn btn-primary">Submit</button>
  </div>
  </form>

  <tr *ngFor="let pd of list">
      <td >{{pd.ActualLogin}}</td>
      <td >{{pd.ActualLogout}}</td>
      <td >{{pd.ShiftLogin}}</td>
      <td>
        <i class="far fa-trash-alt fa-lg text-danger" ></i>
      </td>
    </tr>

And now how can i read it properly so that i can load it in a table.

With the code above. It doesn't even populate the table. But it calls the console.log

I tried searching for a solution for hours now. But i'm lost. I don't understand the tutorials and i can't make it work.

This is the response from my web api. I read it from the response tab in the chrome web browser

{"emp_Id":963,"actualLogin":"05:00:11","actualLogout":"05:01:00","shiftLogin":"05:00:00","shiftLogout":"13:00:00","date":"2019-04-03T00:00:00Z"}

This data is what i want to be populated in the table

Thank you.

Answer 1

I don't think this was the problem,

there is spell mistake in your template, pd.ActualLogin but actually in JSON response it is spelled as actualLogin . Change your template to

   <tr *ngFor="let pd of list">
      <td >{{pd.actualLogin}}</td>
      <td >{{pd.actualLogout}}</td>
      <td >{{pd.shiftLogin}}</td>
      <td>
        <i class="far fa-trash-alt fa-lg text-danger" ></i>
      </td>
    </tr>

Answer 2

Save the result in some variable

example

this.http.post('http://localhost:5000/api/DataCorrection/DataCorrection', this.form.value)
    .toPromise()
    .then(res => {
      result = res;
      console.log('Res ' + res);
    });

And try displaying in UI

example

<div>{{result|json}}</div>

This will display result in json format

Note: use ngFor to display result in table based of your output format

Answer 3

You are doing a cross domain request because your api and Angular app are being served on different ports. You can either add a cors header to accept all domains on your api (not recommended) or you can setup a proxy.config.json file so that your api calls are redirected to the same port as your Angular app.

{
  "/api/*": {
    "target": "http://localhost:5000/api/",
    "pathRewrite": {
      "^/api": ""
    },
    "changeOrigin": true,
    "secure": false,
    "logLevel": "debug"
  }
}

And in your Angular use /api/DataCorrection/DataCorrection instead of http://localhost:5000/api/DataCorrection/DataCorrection

Then serve with

ng serve --proxy-config proxy.config.json