渲染视图到字符串:ArgumentOutOfRangeException
作者:互联网
我有一个asp.net核心应用程序,并且有一个名为ViewRenderService的服务,该服务将视图转换为字符串,以便我根据发出的请求呈现某些视图.
ViewRenderService:
public class ViewRenderService : IViewRenderService
{
private readonly IRazorViewEngine _razorViewEngine;
private readonly ITempDataProvider _tempDataProvider;
private readonly IServiceProvider _serviceProvider;
public ViewRenderService(IRazorViewEngine razorViewEngine,
ITempDataProvider tempDataProvider,
IServiceProvider serviceProvider)
{
_razorViewEngine = razorViewEngine;
_tempDataProvider = tempDataProvider;
_serviceProvider = serviceProvider;
}
public async Task<string> RenderToStringAsync(string viewName, object model)
{
var httpContext = new DefaultHttpContext { RequestServices = _serviceProvider };
var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
using (var sw = new StringWriter())
{
var viewResult = _razorViewEngine.GetView(viewName, viewName, false);
if (viewResult.View == null)
{
throw new ArgumentNullException($"{viewName} does not match any available view");
}
var viewDictionary = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary())
{
Model = model
};
var viewContext = new ViewContext(
actionContext,
viewResult.View,
viewDictionary,
new TempDataDictionary(actionContext.HttpContext, _tempDataProvider),
sw,
new HtmlHelperOptions()
);
await viewResult.View.RenderAsync(viewContext);
return sw.GetStringBuilder().ToString();
}
}
}
该行:
await viewResult.View.RenderAsync
抛出
“System.ArgumentOutOfRangeException: Index was out of range. Must be
non-negative and less than the size of the collection.Parameter name:
index”
在某些模型/视图上
视图和模型在以下方面引发异常:
VerifyCodeViewModel:
public class VerifyCodeViewModel
{
[Required (ErrorMessage = "Please enter verification code that was sent via email")]
public string Code { get; set; }
public string ReturnUrl { get; set; }
}
Verify.cshtml
@model VerifyCodeViewModel
<div class="row">
<div class="col s12 m5 l5 push-m3 push-l3 center">
<div class="center">
<br />
<form method="post" asp-action="Verify">
<div class="card">
<div class="card-content">
<div class="red-text text-bold" asp-validation-summary="ModelOnly"></div>
<div class="row">
<div class="col 12 m12 l12">
<h4 class="text-bold header caption-uppercase">Verification Token Required</h4>
</div>
</div>
<div class="row">
<div class="col s12 m12 l12">
<p class="center-align">
An email that contains a token have been sent to you. Please enter token below.
</p>
</div>
</div>
<div class="row">
<div class="input-field col 12 m12 l12">
<i class="mdi-communication-vpn-key prefix"></i>
<input type="text" asp-for="Code" placeholder="Enter token here"/>
<span asp-validation-for="Code"></span>
<span class="text-bold red-text">@ViewBag.Message</span>
</div>
</div>
</div>
<div class="card-action">
<button type="submit" class="btn btn-danger">Verify</button>
</div>
</div>
</form>
</div>
</div>
</div>
@section Scripts {
@{ await Html.RenderPartialAsync("_ValidationScriptsPartial"); }
}
请指导我有关我所缺少的内容,因为它确实适用于某些视图,但不适用于上述视图.
解决方法:
我遇到了同样的问题,并通过检查调用堆栈找到了答案.我这边的问题是:
at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
at System.Collections.Generic.List`1.get_Item(Int32 index)
at Microsoft.AspNetCore.Mvc.Routing.UrlHelper.get_Router()
at Microsoft.AspNetCore.Mvc.Routing.UrlHelper.GetVirtualPathData(String routeName, RouteValueDictionary values)
at Microsoft.AspNetCore.Mvc.Routing.UrlHelper.Action(UrlActionContext actionContext)
因此缺少了路由器,并且通过将代码更改为以下内容解决了此问题:
public class ViewRenderService : IViewRenderService
{
private readonly IRazorViewEngine _razorViewEngine;
private readonly ITempDataProvider _tempDataProvider;
private readonly IServiceProvider _serviceProvider;
private readonly HttpContext _context;
public ViewRenderService(IRazorViewEngine razorViewEngine,
ITempDataProvider tempDataProvider,
IServiceProvider serviceProvider,
IHttpContextAccessor accessor)
{
_razorViewEngine = razorViewEngine;
_tempDataProvider = tempDataProvider;
_serviceProvider = serviceProvider;
_context = accessor.HttpContext;
}
public async Task<string> RenderToStringAsync(string viewName, object model)
{
var actionContext = new ActionContext(_context, new RouteData(), new ActionDescriptor());
using (var sw = new StringWriter())
{
var viewResult = _razorViewEngine.GetView(viewName, viewName, false);
if (viewResult.View == null)
{
throw new ArgumentNullException($"{viewName} does not match any available view");
}
var viewDictionary = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary())
{
Model = model
};
var viewContext = new ViewContext(
actionContext,
viewResult.View,
viewDictionary,
new TempDataDictionary(actionContext.HttpContext, _tempDataProvider),
sw,
new HtmlHelperOptions()
);
viewContext.RouteData = _context.GetRouteData();
await viewResult.View.RenderAsync(viewContext);
return sw.GetStringBuilder().ToString();
}
}
}
实际上帮助将上下文从新的ActionContext更改为注入的上下文.通过更改此设置,然后设置RouteData,可以解决此问题.
viewContext.RouteData = _context.GetRouteData();
标签:razorengine,asp-net-core,asp-net,c,asp-net-mvc 来源: https://codeday.me/bug/20191025/1932531.html