页码显示在第一页

Question

我使用 unsplash api 创建了一个图像搜索网站，并添加了分页功能。问题是当我搜索图像时，所有页码都在第一页。假设有 2000 页的搜索结果，那么所有的页码按钮都显示在第一页。但是，当我单击任何页码时，一切正常。我也希望在第一页中，页码正常显示，如prev, 1,2,....5,next。我已将page=1 赋予fetchPosts 函数。然而，这似乎并不能解决问题。此外，它在网站的初始加载时也能正常工作。当您搜索某些内容时，问题就会出现。我该如何解决这个问题？

import React, { Component } from "react";
import Pagination from "./Pagination";
import List from "./List";
import "./styles.css";
import axios from "axios";

const LOAD_STATE = {
  SUCCESS: "SUCCESS",
  ERROR: "ERROR",
  LOADING: "LOADING"
};

const appId =
  "22b7b54287910389edfae878f576488bbc5b540a46daa0d2833ba858ce03b143";
const BASE_URL = "https://api.unsplash.com/photos?page=1";

export default class App extends Component {
  constructor() {
    super();
    this.handleChange = this.handleChange.bind(this);
    this.fetchPhotos = this.fetchPhotos.bind(this);
    this.state = {
      photos: [],
      totalPhotos: 0,
      perPage: 5,
      currentPage: 1,
      loadState: LOAD_STATE.LOADING,
      search: ""
    };
  }
  handleChange(e) {
    this.setState({ search: e.target.value });
  }

  componentDidMount() {
    this.fetchPhotos(this.state.currentPage);
  }

  fetchPhotos(page = 1) {
    var self = this;
    const { search, perPage } = this.state;
    const url1 = `https://api.unsplash.com/photos?page=${page}&client_id=${appId}`;
    const url2 =
      `https://api.unsplash.com/search/photos?page=${page}&query=` +
      search +
      "&client_id=" +
      appId;
    const url = search ? url2 : url1;

    if (search) {
      const options = {
        params: {
          page: page,
          per_page: perPage,
          order_by: "popularity"
        }
      };

      this.setState({ loadState: LOAD_STATE.LOADING });
      axios
        .get(url, options)
        .then(response => {
          this.setState({
            photos: response.data.results,
            totalPhotos: parseInt(response.headers["x-total"]),
            currentPage: page,
            loadState: LOAD_STATE.SUCCESS
          });
        })
        .catch(() => {
          this.setState({ loadState: LOAD_STATE.ERROR });
        });
    } else {
      const options = {
        params: {
          client_id: appId,
          page: page,
          per_page: perPage,
          order_by: "popularity"
        }
      };

      this.setState({ loadState: LOAD_STATE.LOADING });
      axios
        .get(url, options)
        .then(response => {
          self.setState({
            photos: response.data,
            totalPhotos: parseInt(response.headers["x-total"]),
            currentPage: page,
            loadState: LOAD_STATE.SUCCESS
          });
        })
        .catch(() => {
          this.setState({ loadState: LOAD_STATE.ERROR });
        });
    }
  }

  render() {
    return (
      <div className="app">
        <input
          onChange={this.handleChange}
          type="text"
          name="search"
          placeholder="Enter query"
        />
        <button type="submit" onClick={this.fetchPhotos} className="button">
          Submit
        </button>
        <Pagination
          current={this.state.currentPage}
          total={this.state.totalPhotos}
          perPage={this.state.perPage}
          onPageChanged={this.fetchPhotos.bind(this)}
        />
        {this.state.loadState === LOAD_STATE.LOADING ? (
          <div className="loader" />
        ) : (
          <List data={this.state.photos} />
        )}
      </div>
    );
  }
}

分页

import React, { Component } from "react";

export default class Pagination extends Component {
  pages() {
    var pages = [];
    for (var i = this.rangeStart(); i <= this.rangeEnd(); i++) {
      pages.push(i);
    }
    return pages;
  }

  rangeStart() {
    var start = this.props.current - this.props.pageRange;
    return start > 0 ? start : 1;
  }

  rangeEnd() {
    var end = this.props.current + this.props.pageRange;
    var totalPages = this.totalPages();
    return end < totalPages ? end : totalPages;
  }

  totalPages() {
    return Math.ceil(this.props.total / this.props.perPage);
  }

  nextPage() {
    return this.props.current + 1;
  }

  prevPage() {
    return this.props.current - 1;
  }

  hasFirst() {
    return this.rangeStart() !== 1;
  }

  hasLast() {
    return this.rangeEnd() < this.totalPages();
  }

  hasPrev() {
    return this.props.current > 1;
  }

  hasNext() {
    return this.props.current < this.totalPages();
  }

  changePage(page) {
    this.props.onPageChanged(page);
  }

  render() {
    return (
      <div className="pagination">
        <div className="pagination__left">
          <a
            href="#"
            className={!this.hasPrev() ? "hidden" : ""}
            onClick={e => this.changePage(this.prevPage())}
          >
            Prev
          </a>
        </div>

        <div className="pagination__mid">
          <ul>
            <li className={!this.hasFirst() ? "hidden" : ""}>
              <a href="#" onClick={e => this.changePage(1)}>
                1
              </a>
            </li>
            <li className={!this.hasFirst() ? "hidden" : ""}>...</li>
            {this.pages().map((page, index) => {
              return (
                <li key={index}>
                  <a
                    href="#"
                    onClick={e => this.changePage(page)}
                    className={this.props.current == page ? "current" : ""}
                  >
                    {page}
                  </a>
                </li>
              );
            })}
            <li className={!this.hasLast() ? "hidden" : ""}>...</li>
            <li className={!this.hasLast() ? "hidden" : ""}>
              <a href="#" onClick={e => this.changePage(this.totalPages())}>
                {this.totalPages()}
              </a>
            </li>
          </ul>
        </div>

        <div className="pagination__right">
          <a
            href="#"
            className={!this.hasNext() ? "hidden" : ""}
            onClick={e => this.changePage(this.nextPage())}
          >
            Next
          </a>
        </div>
      </div>
    );
  }
}

Pagination.defaultProps = {
  pageRange: 2
};

Answer 1

问题是你使用fetchPhotos函数有两种不同的方式

  onClick={this.fetchPhotos}

在此情景中，您不传递页码，而是传递事件，因此它无法知道您在哪个页面。将其更改为此，它应该可以工作。 我想对于每个提交按钮，它应该默认为第一页。

<button
  type="submit"
  onClick={() => this.fetchPhotos(1)}
  className="button"
>