Question

我试图使用Tomas Petricek在这个网站上写的解决方案，但不是用于字符串而是用于图像。不幸的是，它不起作用。这是我的代码：

型号：

let ChartModelCumulativePerformance =
   let numMths                  = 60
   let trackOfDates numMths     = firstDate.AddMonths(numMths)
   let trackHF                  = [for x in 0 .. 59 ->(trackOfDates x, HFReturns.[x])]
   let trackBchk                = [for x in 0 .. 59 ->(trackOfDates x, BchkReturns.[x])]
   Chart.Line(trackHF,Name="Hedge Fund") |> ignore
   Chart.Line(trackBchk,Name="Benchmark") |> ignore
   let myChart =  Chart.Combine(
   [Chart.Line(trackHF,Name="Hedge Fund")
    Chart.Line(trackBchk,Name="Benchmark")])
   myChart.CopyAsBitmap()
member this.CreateCumulativePerformanceGraph() = ChartModelCumulativePerformance

控制器：

 let dataChart = res.CreateCumulativePerformanceGraph()
 let (?<-) (viewData:ViewDataDictionary) (name:string) (value: Image) = viewData.Add(name, value)
 this.ViewData?chartCumulative <- dataChart
 this.View("HFAnalysis") :> ActionResult

查看

<img src =@ViewBag.chartCumulative height="80" width="80"/ alt="" />

或

<img src =@ViewData["chartCumulative"] height="80" width="80"/ alt="" />

否则，你知道其他方法吗？提前感谢您的帮助

Answer 1

最终你有一个HTML问题，而不是这里的F＃问题。

如果要将图像数据直接放入src标记的img属性中，则必须将其转换为base-64字符串，然后根据相应的元数据为其添加前缀。到Data URI standard。

我会将您的位图转换为PNG（缩小文件大小），然后获取图像的字节数组并将其传递给Convert.ToBase64String。最终你会得到这样的东西：

<img width="80" height="80" src="data:image/png;base64,R0lGODlhEAAQAMQAAORHHOVSKudfOulrSOp3WOyDZu6QdvCchPGolfO0o/XBs/fNwfjZ0frl3/zy7////wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAkAABAALAAAAAAQABAAAAVVICSOZGlCQAosJ6mu7fiyZeKqNKToQGDsM8hBADgUXoGAiqhSvp5QAnQKGIgUhwFUYLCVDFCrKUE1lBavAViFIDlTImbKC5Gm2hB0SlBCBMQiB0UjIQA7" />

Answer 2

非常感谢Joel !!!! 这是有兴趣的人的代码：

型号：

 let ChartModelCumulativePerformance =
   //... code for building a Chart
   let myChart      = myChart.CopyAsBitmap()
   let ms           = new MemoryStream()
   let tempVar      = myChart.Save(ms,Imaging.ImageFormat.Png)
   let imageData    = ms.ToArray()
   let imageBase64  = Convert.ToBase64String(imageData)
   String.Format("data:image/png;base64,{0}", imageBase64)

控制器：

let dataChart = res.CreateCumulativePerformanceGraph()
let (?<-) (viewData:ViewDataDictionary) (name:string) (value: String) = viewData.Add(name, value)
this.ViewData?chartCumulative <- dataChart
  this.View("HFAnalysis") :> ActionResult

查看：

F＃在ViewBag动态对象上设置属性（传递图像）

2 个答案: