/// <summary>
/// 使用Razor视图引擎来生成代码文件
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <param name="viewPath"></param>
/// <param name="model"></param>
/// <returns></returns>
private string Render <TModel>(string viewPath, TModel model)
{
DefaultHttpContext httpContext = new DefaultHttpContext {
RequestServices = _serviceProvider
};
ActionContext actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineResult viewResult = _viewEngine.GetView(null, viewPath, false);
if (!viewResult.Success)
{
throw new InvalidOperationException($"找不到视图模板 {viewPath}");
}
ViewDataDictionary viewDictionary = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary())
{
Model = model
};
using (StringWriter writer = new StringWriter())
{
ViewContext viewContext = new ViewContext(
actionContext,
viewResult.View,
viewDictionary,
new TempDataDictionary(actionContext.HttpContext, _tempDataProvider),
writer,
new HtmlHelperOptions()
);
Task render = viewResult.View.RenderAsync(viewContext);
render.Wait();
return(writer.ToString());
}
}
/// <summary>
/// Renderiza uma view como string.
/// </summary>
/// <param name="viewName"></param>
/// <param name="model"></param>
/// <returns></returns>
public async Task <string> RenderToStringAsync(string viewName, object model)
{
var httpContext = new DefaultHttpContext {
RequestServices = serviceProvider
};
var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
using (var sw = new StringWriter())
{
Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineResult viewResult = razorViewEngine.FindView(actionContext, viewName, false);
if (viewResult.View == null)
{
throw new ArgumentNullException($"{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.ToString());
}
}
public static string ToHtml(this ViewResult result, HttpContext httpContext)
{
try
{
IRoutingFeature feature = httpContext.Features.Get <IRoutingFeature>();
RouteData routeData = feature.RouteData;
string viewName = result.ViewName ?? routeData.Values["action"] as string;
ActionContext actionContext = new ActionContext(httpContext, routeData, new ControllerActionDescriptor());
IOptions <MvcViewOptions> options = httpContext.RequestServices.GetRequiredService <IOptions <MvcViewOptions> >();
Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelperOptions htmlHelperOptions = options.Value.HtmlHelperOptions;
Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineResult viewEngineResult = result.ViewEngine?.FindView(actionContext, viewName, true) ?? options.Value.ViewEngines.Select(x => x.FindView(actionContext, viewName, true)).FirstOrDefault(x => x != null);
Microsoft.AspNetCore.Mvc.ViewEngines.IView view = viewEngineResult.View;
StringBuilder builder = new StringBuilder();
using (StringWriter output = new StringWriter(builder))
{
ViewContext viewContext = new ViewContext(actionContext, view, result.ViewData, result.TempData, output, htmlHelperOptions);
view
.RenderAsync(viewContext)
.GetAwaiter()
.GetResult();
}
return(builder.ToString());
}
catch
{
return(string.Empty);
}
}
public async Task <string> GetTemplateHtmlAsStringAsync <T>(string viewName, T model)
{
var httpContext = new DefaultHttpContext()
{
RequestServices = _serviceProvider
};
var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
using var sw = new StringWriter();
Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineResult viewResult = _razorViewEngine.FindView(actionContext, viewName, false);
if (viewResult.View == null)
{
return(string.Empty);
}
var viewDataDictionary = new ViewDataDictionary(
new EmptyModelMetadataProvider(),
new ModelStateDictionary()
)
{
Model = model
};
var viewContext = new ViewContext(
actionContext,
viewResult.View,
viewDataDictionary,
new TempDataDictionary(actionContext.HttpContext, _tempDataProvider),
sw,
new HtmlHelperOptions()
);
await viewResult.View.RenderAsync(viewContext);
return(sw.ToString());
}
/// <summary>
/// Render partial view to string
/// </summary>
/// <param name="viewName">View name</param>
/// <param name="model">Model</param>
/// <returns>Result</returns>
protected virtual string RenderPartialViewToString(string viewName, object model)
{
//get Razor view engine
IRazorViewEngine razorViewEngine = ServiceProviderFactory.ServiceProvider.GetRequiredService <IRazorViewEngine>();
//create action context
ActionContext actionContext = new ActionContext(this.HttpContext, this.RouteData, this.ControllerContext.ActionDescriptor, this.ModelState);
//set view name as action name in case if not passed
if (string.IsNullOrEmpty(viewName))
{
viewName = this.ControllerContext.ActionDescriptor.ActionName;
}
//set model
ViewData.Model = model;
//try to get a view by the name
Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineResult viewResult = razorViewEngine.FindView(actionContext, viewName, false);
if (viewResult.View == null)
{
//or try to get a view by the path
viewResult = razorViewEngine.GetView(null, viewName, false);
if (viewResult.View == null)
{
throw new ArgumentNullException($"{viewName} view was not found");
}
}
using (StringWriter stringWriter = new StringWriter())
{
ViewContext viewContext = new ViewContext(actionContext, viewResult.View, ViewData, TempData, stringWriter, new HtmlHelperOptions());
System.Threading.Tasks.Task t = viewResult.View.RenderAsync(viewContext);
t.Wait();
return(stringWriter.GetStringBuilder().ToString());
}
}
public async Task <string> RenderTemplateAsync <TViewModel>(RouteData routeData,
string viewName, TViewModel viewModel, Dictionary <string, object> additonalViewDictionary = null, bool isMainPage = true) where TViewModel : IViewData
{
var httpContext = new DefaultHttpContext
{
RequestServices = _serviceProvider
};
if (viewModel.RequestPath != null)
{
httpContext.Request.Host = HostString.FromUriComponent(viewModel.RequestPath.Host);
httpContext.Request.Scheme = viewModel.RequestPath.Scheme;
httpContext.Request.PathBase = PathString.FromUriComponent(viewModel.RequestPath.PathBase);
_logger.LogDebug($"RequestPath != null");
_logger.LogTrace($"\tHost: {viewModel.RequestPath.Host} -> {httpContext.Request.Host}");
_logger.LogTrace($"\tScheme: {viewModel.RequestPath.Scheme}");
_logger.LogTrace($"\tPathBase: {viewModel.RequestPath.PathBase} -> {httpContext.Request.PathBase}");
}
var actionDescriptor = new ActionDescriptor
{
RouteValues = routeData.Values.ToDictionary(kv => kv.Key, kv => kv.Value.ToString())
};
var actionContext = new ActionContext(httpContext, routeData, actionDescriptor);
using (var outputWriter = new StringWriter())
{
Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineResult viewResult = null;
if (IsApplicationRelativePath(viewName) || IsRelativePath(viewName))
{
_logger.LogDebug($"Relative path");
#if NETSTANDARD2_0
viewResult = _viewEngine.GetView(_hostingEnvironment.WebRootPath, viewName, isMainPage);
#else
if (_hostingEnvironment is Microsoft.AspNetCore.Hosting.IWebHostEnvironment webHostEnvironment)
{
_logger.LogDebug($"_hostingEnvironment is IWebHostEnvironment -> GetView from WebRootPath: {webHostEnvironment.WebRootPath}");
viewResult = _viewEngine.GetView(webHostEnvironment.WebRootPath, viewName, isMainPage);
}
else
{
_logger.LogDebug($"_hostingEnvironment is IHostEnvironment -> GetView from ContentRootPath: {_hostingEnvironment.ContentRootPath}");
viewResult = _viewEngine.GetView(_hostingEnvironment.ContentRootPath, viewName, isMainPage);
}
#endif
}
else
{
_logger.LogDebug($"Not a relative path");
viewResult = _viewEngine.FindView(actionContext, viewName, isMainPage);
}
var viewDictionary = new ViewDataDictionary <TViewModel>(viewModel.ViewData, viewModel);
if (additonalViewDictionary != null)
{
_logger.LogDebug($"additonalViewDictionary count: {additonalViewDictionary.Count}");
foreach (var kv in additonalViewDictionary)
{
if (!viewDictionary.ContainsKey(kv.Key))
{
viewDictionary.Add(kv);
}
else
{
viewDictionary[kv.Key] = kv.Value;
}
}
}
var tempDataDictionary = new TempDataDictionary(httpContext, _tempDataProvider);
if (!viewResult.Success)
{
_logger.LogError($"Failed to render template {viewName} because it was not found. \r\nThe following locations are searched: \r\n{string.Join("\r\n", viewResult.SearchedLocations) }");
throw new TemplateServiceException($"Failed to render template {viewName} because it was not found. \r\nThe following locations are searched: \r\n{string.Join("\r\n", viewResult.SearchedLocations) }");
}
try
{
var viewContext = new ViewContext(actionContext, viewResult.View, viewDictionary,
tempDataDictionary, outputWriter, new HtmlHelperOptions());
await viewResult.View.RenderAsync(viewContext);
}
catch (Exception ex)
{
_logger.LogError(ex, "Failed to render template due to a razor engine failure");
throw new TemplateServiceException("Failed to render template due to a razor engine failure", ex);
}
await outputWriter.FlushAsync();
return(outputWriter.ToString());
}
}
