C# 如何使用木偶手来获得表演的价值。时间来源？

使用PuppeterSharep，我尝试使用下面的C代码获取

performance.timeOrigin

值：

JToken performanceTimeOriginString = await _page.EvaluateFunctionAsync("JSON.stringify(performance.timeOrigin);").ConfigureAwait(false);

我已经在JavaScript控制台中验证了这一点：

但是，当我运行上面的PuppeterSharp代码时，我得到以下异常：

System.AggregateException: One or more errors occurred. (Evaluation failed: SyntaxError: Unexpected token ';') ---> PuppeteerSharp.EvaluationFailedException: Evaluation failed: SyntaxError: Unexpected token ';'
at PuppeteerSharp.ExecutionContext.ExecuteEvaluationAsync(String method, Object args)
at PuppeteerSharp.ExecutionContext.RemoteObjectTaskToObject[T](Task`1 remote)
at PuppeteerSharp.DOMWorld.EvaluateFunctionAsync[T](String script, Object[] args)
--- End of inner exception stack trace ---

它告诉我删除分号（非常奇怪），所以我尝试了一下，但得到了下面的例外

System.AggregateException: One or more errors occurred. (Protocol error (Runtime.callFunctionOn): Given expression does not evaluate to a function) ---> PuppeteerSharp.EvaluationFailedException: Protocol error (Runtime.callFunctionOn): Given expression does not evaluate to a function ---> PuppeteerSharp.MessageException: Protocol error (Runtime.callFunctionOn): Given expression does not evaluate to a function
at PuppeteerSharp.CDPSession.SendAsync(String method, Object args, Boolean waitForCallback)
at PuppeteerSharp.CDPSession.SendAsync[T](String method, Object args)
at PuppeteerSharp.ExecutionContext.ExecuteEvaluationAsync(String method, Object args)
--- End of inner exception stack trace ---

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我如何使用PuppeterSharep来获取性能值。timeOrigin？您应该使用

EvaluateExpressionAsync

_page.EvaluateExpressionAsync("JSON.stringify(performance.timeOrigin)").ConfigureAwait(false);

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您应该使用

EvaluateExpressionAsync

_page.EvaluateExpressionAsync("JSON.stringify(performance.timeOrigin)").ConfigureAwait(false);