Question

我需要从Firestore数据库中获取所有数据。我遵循这种方式，https://stackoverflow.com/a/55865045/9139407

$('li.nav-item').click(function() {

    id = $(this).data('id');
    name = $(this).data('name');
    rate = $(this).data('rate');
    value = $(this).data('value');

    $('#' + id + '_name').empty();
    $('#' + id + '_rate').empty();
    $('#' + id + '_rate').attr('data-item-rate', 0);

    if(value != 0) {
        value_sign = '$' + value;

        $('#' + id + '_name').html('<strong>' + name + '</strong>');
        $('#' + id + '_rate').html(value_sign);
        $('#' + id + '_rate').attr('data-item-rate', value);
    }

    updateTotal();
});

// Update the total
function updateTotal() {

    var total = 0;

    $('p[data-item-rate]').each(function() {
        total += isNaN(parseInt($(this).data('item-rate'))) ? 0 : parseInt($(this).data('item-rate'));
    });

    total = total + ' $';

    $('#total_estimate').html(total);
}

错误消息是：

未处理的异常：类型'Future '不是类型的子类型 'Future <摄影>'

摄影模型课

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="col-lg-8">
    <div class="row">
        <div class="col-lg-6">
            <h2>Photos gallery</h2>
        </div>
        <div class="col-lg-6">
            <ul class="nav nav-tabs-outline">
                <li class="nav-item" data-id="gallery" data-name="Photos gallery" data-rate="No" data-value="0">
                    <a class="nav-link active" data-toggle="tab" href="#">
                    No
                    </a>
                </li>
                <li class="nav-item" data-id="gallery" data-name="Galerie photos" data-rate="Yes" data-value="300">
                    <a class="nav-link " data-toggle="tab" href="#">
                    Yes
                    <span class="badge badge-secondary">+ 300 $</span>
                    </a>
                </li>
            </ul>
        </div>
    </div>
    <hr>
    <div class="row">
        <div class="col-lg-6">
            <h2>Contact form</h2>
        </div>
        <div class="col-lg-6">
            <ul class="nav nav-tabs-outline">
                <li class="nav-item" data-id="contact-form" data-name="Contact form" data-rate="No" data-value="0">
                    <a class="nav-link active" data-toggle="tab" href="#">
                    No
                    </a>
                </li>
                <li class="nav-item" data-id="contact-form" data-name="Formulaire de contact" data-rate="Yes" data-value="250">
                    <a class="nav-link " data-toggle="tab" href="#">
                    Yes
                    <span class="badge badge-secondary">+ 250 $</span>
                    </a>
                </li>
            </ul>
        </div>
    </div>
    <hr>
    <div class="row">
        <div class="col-lg-6">
            <h2>Newsletter</h2>
        </div>
        <div class="col-lg-6">
            <ul class="nav nav-tabs-outline">
                <li class="nav-item" data-id="newsletter" data-name="Abonnement infolettre" data-rate="No" data-value="0">
                    <a class="nav-link active" data-toggle="tab" href="#">
                    No
                    </a>
                </li>
                <li class="nav-item" data-id="newsletter" data-name="Abonnement infolettre" data-rate="Yes" data-value="250">
                    <a class="nav-link " data-toggle="tab" href="#">
                    Yes
                    <span class="badge badge-secondary">+ 250 $</span>
                    </a>
                </li>
            </ul>
        </div>
    </div>
    <hr>
</div>



<div class="col-lg-4">
    <div class="cart-price">
        <div class="flexbox">
            <div>
                <p id="gallery_name"></p>
                <p id="gallery_rate" data-item-rate="0"></p>
                <hr />
                <p id="contact-form_name"></p>
                <p id="contact-form_rate" data-item-rate="0"></p>
                <hr />
                <p id="newsletter_name"></p>
                <p id="newsletter_rate" data-item-rate="0"></p>

            </div>
        </div>
        <hr>
        <div class="flexbox">
            <div>
                <p><strong>Total:</strong></p>
            </div>
            <div>
                <p class="fw-600" id="total_estimate">0 $</p>
            </div>
        </div>
    </div>
</div>

下一个问题是，如何将这些数据添加到集团接收器上？

 Future<Photography> getPhotography() {
  Future<Photography> data =  await db
    .collection('photography')
    .document('0yUc5QBGHNNq6WK9CyyF')
    .setData(jsonDecode(jsonEncode(Photography(
  [AllImages(["list"])],
  "image_url",
  "Shanika",
  "image_url",
  "lovely couple",
  "Bhanuka"
))));

return data;
}

像这样？但是错误是，参数类型'Future'不能分配给参数类型'Photography'

import 'package:json_annotation/json_annotation.dart';
part 'Model.g.dart';

@JsonSerializable()
class Photography{
   List<AllImages> all_images;
   String couplePhoto;
   String female;
   String image_url;
   String info;
   String male;

  Photography();

  factory Photography.fromJson(Map<String, dynamic> json) => _$PhotographyFromJson(json);
   Map<String,dynamic> toJson() => _$PhotographyToJson(this);
}

@JsonSerializable()
class AllImages {
  final List<String> imageUrl;

  AllImages(this.imageUrl);

  factory AllImages.fromJson(Map<String, dynamic> json) => _$AllImagesFromJson(json);
  Map<String,dynamic> toJson() => _$AllImagesToJson(this);
}

Answer 1

Document.setData()返回Future<void>-表示将来完成时不会返回任何数据。当然，对于二传手来说这是合理的。这就是为什么您不能将其变成任何东西的原因。目前尚不清楚您打算从哪里获得data。您从一个空（？）Photography开始，对其进行编码，解码并存储，然后期望返回某些内容。什么？原来的空物体？（您可以退还-但我认为那不是您想要的。）

未处理的异常：Firestore上的类型'Future <void>'不是类型'Future <Photography>'的子类型

1 个答案: