步骤 4 - 探索 .NET 搜索代码

在前面的课程中，你已将搜索添加到静态 Web 应用。 本课重点介绍了建立集成的必要步骤。 如果你正在寻找有关如何将搜索集成到 Web 应用的速查表，本文便介绍了你需要了解的内容。

Azure SDK Azure.Search.Documents

函数应用使用 Azure SDK 进行 Azure AI 搜索：

• NuGet： Azure.Search.Documents
• 参考文档： 客户端库

函数应用使用资源名称、资源键和索引名称通过 SDK 向基于云的 Azure AI 搜索 API 进行身份验证。 密码存储在静态 Web 应用设置中，并作为环境变量拉取到函数中。

在 local.settings.json 文件中配置机密

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated",
    "SearchApiKey": "",
    "SearchServiceName": "",
    "SearchIndexName": "good-books"
  },
  "Host": {
    "CORS": "*"
  }
}

Azure Function：搜索目录

搜索 API 采用搜索词并搜索搜索索引中的文档，并返回匹配项列表。 通过建议 API，部分字符串在用户键入时将发送到搜索引擎，为搜索索引中的文档建议搜索词（如书籍标题和作者），并返回一个较小的匹配列表。

Azure 函数拉取搜索配置信息并完成查询。

搜索建议器 sg是在批量上传期间使用的 架构文件中 定义的。

using Azure;
using Azure.Core.Serialization;
using Azure.Search.Documents;
using Azure.Search.Documents.Models;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Azure.Functions.Worker.Http;
using Microsoft.Extensions.Logging;
using System.Net;
using System.Text.Json;
using System.Text.Json.Serialization;
using WebSearch.Models;
using SearchFilter = WebSearch.Models.SearchFilter;

namespace WebSearch.Function
{
    public class Search
    {
        private static string searchApiKey = Environment.GetEnvironmentVariable("SearchApiKey", EnvironmentVariableTarget.Process);
        private static string searchServiceName = Environment.GetEnvironmentVariable("SearchServiceName", EnvironmentVariableTarget.Process);
        private static string searchIndexName = Environment.GetEnvironmentVariable("SearchIndexName", EnvironmentVariableTarget.Process) ?? "good-books";

        private readonly ILogger<Lookup> _logger;

        public Search(ILogger<Lookup> logger)
        {
            _logger = logger;
        }

        [Function("search")]
        public async Task<HttpResponseData> RunAsync(
            [HttpTrigger(AuthorizationLevel.Anonymous, "post")] HttpRequestData req, 
            FunctionContext executionContext)
        {
            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            var data = JsonSerializer.Deserialize<RequestBodySearch>(requestBody);

            // Azure AI Search 
            Uri serviceEndpoint = new($"https://{searchServiceName}.search.windows.net/");

            SearchClient searchClient = new(
                serviceEndpoint,
                searchIndexName,
                new AzureKeyCredential(searchApiKey)
            );

            SearchOptions options = new()

            {
                Size = data.Size,
                Skip = data.Skip,
                IncludeTotalCount = true,
                Filter = CreateFilterExpression(data.Filters)
            };
            options.Facets.Add("authors");
            options.Facets.Add("language_code");

            SearchResults<SearchDocument> searchResults = searchClient.Search<SearchDocument>(data.SearchText, options);

            var facetOutput = new Dictionary<string, IList<FacetValue>>();
            foreach (var facetResult in searchResults.Facets)
            {
                facetOutput[facetResult.Key] = facetResult.Value
                           .Select(x => new FacetValue { value = x.Value.ToString(), count = x.Count })

                           .ToList();
            }

            // Data to return 
            var output = new SearchOutput
            {
                Count = searchResults.TotalCount,
                Results = searchResults.GetResults().ToList(),
                Facets = facetOutput
            };
            
            var response = req.CreateResponse(HttpStatusCode.Found);

            // Serialize data
            var serializer = new JsonObjectSerializer(
                new JsonSerializerOptions(JsonSerializerDefaults.Web));
            await response.WriteAsJsonAsync(output, serializer);

            return response;
        }

        public static string CreateFilterExpression(List<SearchFilter> filters)
        {
            if (filters is null or { Count: <= 0 })
            {
                return null;
            }

            List<string> filterExpressions = new();


            List<SearchFilter> authorFilters = filters.Where(f => f.field == "authors").ToList();
            List<SearchFilter> languageFilters = filters.Where(f => f.field == "language_code").ToList();

            List<string> authorFilterValues = authorFilters.Select(f => f.value).ToList();

            if (authorFilterValues.Count > 0)
            {
                string filterStr = string.Join(",", authorFilterValues);
                filterExpressions.Add($"{"authors"}/any(t: search.in(t, '{filterStr}', ','))");
            }

            List<string> languageFilterValues = languageFilters.Select(f => f.value).ToList();
            foreach (var value in languageFilterValues)
            {
                filterExpressions.Add($"language_code eq '{value}'");
            }

            return string.Join(" and ", filterExpressions);
        }
    }
}

客户端：从目录中搜索

使用以下代码在 React 客户端 \client\src\pages\Search\Search.jsx 中调用 Azure 函数以搜索书籍。

import React, { useEffect, useState, Suspense } from 'react';
import fetchInstance from '../../url-fetch';
import CircularProgress from '@mui/material/CircularProgress';
import { useLocation, useNavigate } from "react-router-dom";

import Results from '../../components/Results/Results';
import Pager from '../../components/Pager/Pager';
import Facets from '../../components/Facets/Facets';
import SearchBar from '../../components/SearchBar/SearchBar';

import "./Search.css";

export default function Search() {

  let ___location = useLocation();
  const navigate = useNavigate();

  const [results, setResults] = useState([]);
  const [resultCount, setResultCount] = useState(0);
  const [currentPage, setCurrentPage] = useState(1);
  const [q, setQ] = useState(new URLSearchParams(___location.search).get('q') ?? "*");
  const [top] = useState(new URLSearchParams(___location.search).get('top') ?? 8);
  const [skip, setSkip] = useState(new URLSearchParams(___location.search).get('skip') ?? 0);
  const [filters, setFilters] = useState([]);
  const [facets, setFacets] = useState({});
  const [isLoading, setIsLoading] = useState(true);

  let resultsPerPage = top;

  useEffect(() => {
    setIsLoading(true);
    setSkip((currentPage - 1) * top);

    const body = {
      q: q,
      top: top,
      skip: skip,
      filters: filters
    };

    fetchInstance('/api/search', { body, method: 'POST' })
      .then(response => {
        setResults(response.results);
        setFacets(response.facets);
        setResultCount(response.count);
        setIsLoading(false);
      })
      .catch(error => {
        console.log(error);
        setIsLoading(false);
      });

  }, [q, top, skip, filters, currentPage]);

  // pushing the new search term to history when q is updated
  // allows the back button to work as expected when coming back from the details page
  useEffect(() => {
    navigate('/search?q=' + q);
    setCurrentPage(1);
    setFilters([]);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [q]);


  let postSearchHandler = (searchTerm) => {
    //console.log(searchTerm);
    setQ(searchTerm);
  }


  // filters should be applied across entire result set, 
  // not just within the current page
  const updateFilterHandler = (newFilters) => {

    // Reset paging
    setSkip(0);
    setCurrentPage(1);

    // Set filters
    setFilters(newFilters);
  };

  return (
    <main className="main main--search container-fluid">
      <div className="row">
        <div className="search-bar-column col-md-3">
          <div className="search-bar-column-container">
            <SearchBar postSearchHandler={postSearchHandler} query={q} width={false}></SearchBar>
          </div>
          <Facets facets={facets} filters={filters} setFilters={updateFilterHandler}></Facets>
        </div>
        <div className="search-bar-results">
          {isLoading ? (
            <div className="col-md-9">
              <CircularProgress />
            </div>
          ) : (
            <div className="search-results-container">
              <Results documents={results} top={top} skip={skip} count={resultCount} query={q}></Results>
              <Pager className="pager-style" currentPage={currentPage} resultCount={resultCount} resultsPerPage={resultsPerPage} setCurrentPage={setCurrentPage}></Pager>
            </div>
          )}
        </div>
      </div>
    </main>
  );
}

客户端：来自目录的建议

在 React 应用中，建议函数 API 在 \client\src\components\SearchBar\SearchBar.jsx 被调用，作为 Material UI 的 Autocomplete 组件的一部分。 此组件使用输入文本搜索与输入文本匹配的作者和书籍，然后在下拉列表中的可选项处显示这些可能的匹配项。

import React, { useState, useEffect } from 'react';
import { TextField, Autocomplete, Button, Box } from '@mui/material';
import fetchInstance from '../../url-fetch';
import './SearchBar.css';

export default function SearchBar({ postSearchHandler, query, width }) {
  const [q, setQ] = useState(() => query || '');
  const [suggestions, setSuggestions] = useState([]);

  console.log(`width = ${width}`);

  const search = (value) => {
    console.log(`search: ${value}`);
    postSearchHandler(value);
  };

  useEffect(() => {
    console.log(`useEffect getSuggestions: ${q}`);
    if (q) {

      const body = { q, top: 5, suggester: 'sg' };

      fetchInstance('/api/suggest', { body, method: 'POST' })
      .then(response => {
        setSuggestions(response.suggestions.map(s => s.text));
      })
      .catch(error => {
        console.log(error);
        setSuggestions([]);
      });
    }
  }, [q]);


  const onInputChangeHandler = (event, value) => {
    console.log(`onInputChangeHandler: ${value}`);
    setQ(value);
  };


  const onChangeHandler = (event, value) => {
    console.log(`onChangeHandler: ${value}`);
    setQ(value);
    search(value);
  };

  const onEnterButton = (event) => {
    console.log(`onEnterButton: ${q}`);
    // if enter key is pressed
    if (event.key === 'Enter') {
      search(q);
    }
  };

  return (
    <div
      className={width ? "search-bar search-bar-wide" : "search-bar search-bar-narrow"}
    >
      <Box className="search-bar-box">
        <Autocomplete
          className="autocomplete"
          freeSolo
          value={q}
          options={suggestions}
          onInputChange={onInputChangeHandler}
          onChange={onChangeHandler}
          disableClearable
          renderInput={(params) => (
            <TextField
              {...params}
              id="search-box"
              className="form-control rounded-0"
              placeholder="What are you looking for?"
              onBlur={() => setSuggestions([])}
              onClick={() => setSuggestions([])}
            />
          )}
        />
        <div className="search-button" >
          <Button variant="contained" color="primary" onClick={() => {
            console.log(`search button: ${q}`);
            search(q)
          }
          }>
            Search
          </Button>
        </div>
      </Box>
    </div>
  );
}

Azure Function：获取特定文档

文档查找 API 采用 ID 并从搜索索引返回文档对象。

using Azure;
using Azure.Core.Serialization;
using Azure.Search.Documents;
using Azure.Search.Documents.Models;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Azure.Functions.Worker.Http;
using Microsoft.Extensions.Logging;
using System.Net;
using System.Text.Json;
using WebSearch.Models;

namespace WebSearch.Function
{
    public class Lookup
    {
        private static string searchApiKey = Environment.GetEnvironmentVariable("SearchApiKey", EnvironmentVariableTarget.Process);
        private static string searchServiceName = Environment.GetEnvironmentVariable("SearchServiceName", EnvironmentVariableTarget.Process);
        private static string searchIndexName = Environment.GetEnvironmentVariable("SearchIndexName", EnvironmentVariableTarget.Process) ?? "good-books";

        private readonly ILogger<Lookup> _logger;

        public Lookup(ILogger<Lookup> logger)
        {
            _logger = logger;
        }


        [Function("lookup")]
        public async Task<HttpResponseData> RunAsync(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequestData req, 
            FunctionContext executionContext)
        {

            // Get Document Id
            var query = System.Web.HttpUtility.ParseQueryString(req.Url.Query);
            string documentId = query["id"].ToString();

            // Azure AI Search 
            Uri serviceEndpoint = new($"https://{searchServiceName}.search.windows.net/");

            SearchClient searchClient = new(

                serviceEndpoint,
                searchIndexName,
                new AzureKeyCredential(searchApiKey)
            );

            var getDocumentResponse = await searchClient.GetDocumentAsync<SearchDocument>(documentId);

            // Data to return 
            var output = new LookupOutput
            {
                Document = getDocumentResponse.Value
            };

            var response = req.CreateResponse(HttpStatusCode.Found);

            // Serialize data
            var serializer = new JsonObjectSerializer(
                new JsonSerializerOptions(JsonSerializerDefaults.Web));
            await response.WriteAsJsonAsync(output, serializer);

            return response;
        }
    }
}

客户端：获取特定文档

此函数 API 在 \client\src\pages\Details\Details.jsx 作为组件初始化的一部分在 React 应用程序中调用：

import React, { useState, useEffect } from "react";
import { useParams } from 'react-router-dom';
import Rating from '@mui/material/Rating';
import CircularProgress from '@mui/material/CircularProgress';
import Tabs from '@mui/material/Tabs';
import Tab from '@mui/material/Tab';
import Box from '@mui/material/Box';

import fetchInstance from '../../url-fetch';

import "./Details.css";


function CustomTabPanel(props) {
  const { children, value, index, ...other } = props;

  return (
    <div
      className="tab-panel"
      role="tabpanel"
      hidden={value !== index}
      id={`simple-tabpanel-${index}`}
      aria-labelledby={`simple-tab-${index}`}
      {...other}
       // Ensure it takes full width
    >
      {value === index && <Box className="tab-panel-value">{children}</Box>}
    </div>
  );
}

export default function BasicTabs() {
  const { id } = useParams();
  const [document, setDocument] = useState({});
  const [value, setValue] = React.useState(0);
  const [isLoading, setIsLoading] = useState(true);

  useEffect(() => {
    setIsLoading(true);
    fetchInstance('/api/lookup', { query: { id } })
      .then(response => {
        console.log(JSON.stringify(response))
        const doc = response.document;
        setDocument(doc);
        setIsLoading(false);
      })
      .catch(error => {
        console.log(error);
        setIsLoading(false);
      });

  }, [id]);

  const handleChange = (event, newValue) => {
    setValue(newValue);
  };


  if (isLoading || !id || Object.keys(document).length === 0) {
    return (
      <div className="loading-container">
        <CircularProgress />
        <p>Loading...</p>
      </div>
    );
  }

  return (
    <Box className="details-box-parent">
      <Box className="details-tab-box-header">
        <Tabs value={value} onChange={handleChange} aria-label="book-details-tabs">
          <Tab label="Result" />
          <Tab label="Raw Data" />
        </Tabs>
      </Box>
      <CustomTabPanel value={value} index={0} className="tab-panel box-content">
        <div className="card-body">
          <h5 className="card-title">{document.original_title}</h5>
          <img className="image" src={document.image_url} alt="Book cover"></img>
          <p className="card-text">{document.authors?.join('; ')} - {document.original_publication_year}</p>
          <p className="card-text">ISBN {document.isbn}</p>
          <Rating name="half-rating-read" value={parseInt(document.average_rating)} precision={0.1} readOnly></Rating>
          <p className="card-text">{document.ratings_count} Ratings</p>
        </div>
      </CustomTabPanel>
      <CustomTabPanel value={value} index={1} className="tab-panel">
        <div className="card-body text-left card-text details-custom-tab-panel-json-div" >
          <pre><code>
            {JSON.stringify(document, null, 2)}
          </code></pre>
        </div>
      </CustomTabPanel>
    </Box>
  );
}

支持函数应用的 C# 模型

以下模型用于支持此应用中的函数。

using Azure.Search.Documents.Models;
using System.Text.Json.Serialization;

namespace WebSearch.Models
{
    public class RequestBodyLookUp
    {
        [JsonPropertyName("id")]
        public string Id { get; set; }
    }

    public class RequestBodySuggest
    {
        [JsonPropertyName("q")]
        public string SearchText { get; set; }

        [JsonPropertyName("top")]
        public int Size { get; set; }

        [JsonPropertyName("suggester")]
        public string SuggesterName { get; set; }
    }

    public class RequestBodySearch
    {
        [JsonPropertyName("q")]
        public string SearchText { get; set; }

        [JsonPropertyName("skip")]
        public int Skip { get; set; }

        [JsonPropertyName("top")]
        public int Size { get; set; }

        [JsonPropertyName("filters")]
        public List<SearchFilter> Filters { get; set; }
    }

    public class SearchFilter
    {
        public string field { get; set; }
        public string value { get; set; }
    }

    public class FacetValue
    {
        public string value { get; set; }
        public long? count { get; set; }
    }

    class SearchOutput
    {
        [JsonPropertyName("count")]
        public long? Count { get; set; }
        [JsonPropertyName("results")]
        public List<SearchResult<SearchDocument>> Results { get; set; }
        [JsonPropertyName("facets")]
        public Dictionary<String, IList<FacetValue>> Facets { get; set; }
    }
    class LookupOutput
    {
        [JsonPropertyName("document")]
        public SearchDocument Document { get; set; }
    }
    public class BookModel
    {
        public string id { get; set; }
        public decimal? goodreads_book_id { get; set; }
        public decimal? best_book_id { get; set; }
        public decimal? work_id { get; set; }
        public decimal? books_count { get; set; }
        public string isbn { get; set; }
        public string isbn13 { get; set; }
        public string[] authors { get; set; }
        public decimal? original_publication_year { get; set; }
        public string original_title { get; set; }
        public string title { get; set; }
        public string language_code { get; set; }
        public double? average_rating { get; set; }
        public decimal? ratings_count { get; set; }
        public decimal? work_ratings_count { get; set; }
        public decimal? work_text_reviews_count { get; set; }
        public decimal? ratings_1 { get; set; }
        public decimal? ratings_2 { get; set; }
        public decimal? ratings_3 { get; set; }
        public decimal? ratings_4 { get; set; }
        public decimal? ratings_5 { get; set; }
        public string image_url { get; set; }
        public string small_image_url { get; set; }
    }
}

后续步骤

若要继续了解有关 Azure AI 搜索开发的详细信息，请尝试下一个有关索引的教程：

• 编制 Azure SQL 数据索引