在ASP.NET Core Blazor WebAssembly应用程序中,当您尝试使用FetchData组件与SQL Server数据库通信时会遇到一些问题。具体来说,您可能会遇到无法从数据库获取数据的情况。
此问题是由于组件中的使用了默认情况下不支持远程请求的HttpClient。为了解决这个问题,您应该使用一个HttpClientHandler。以下代码示例显示如何配置Teleport.HttpClientHandler:
在程序包管理器控制台中安装Teleport.HttpClientHandler:
Install-Package Teleport.HttpClientHandler -Version 1.2.1
在FetchData.razor文件中添加以下代码:
@page "/fetchdata"
@using System.Net.Http
@using System.Collections.Generic
@using System.Threading.Tasks
@using Microsoft.AspNetCore.Components
@using Newtonsoft.Json
@using Teleport.HttpClientHandler
Weather forecast
This component demonstrates fetching data from the server and displaying it.
@if (forecasts == null)
{
Loading...
}
else
{
Date
Temp. (C)
Temp. (F)
Summary
@foreach (var forecast in forecasts)
{
@forecast.Date.ToShortDateString()
@forecast.TemperatureC
@forecast.TemperatureF
@forecast.Summary
}
}
@code {
private WeatherForecast[] forecasts;
private HttpClient httpClient;
protected override async Task OnInitializedAsync()
{
await base.OnInitializedAsync();
var handler = new TeleportHandler();
httpClient = new HttpClient(handler)
{
BaseAddress = new Uri("https://localhost:44374")
};
forecasts = await httpClient.GetJson