MVVM WPF网络摄像头不起作用..? [英] MVVM WPF Webcam Not Working..?

问题描述

我正在一个项目上，需要通过mvvm模式流式传输视频.我在代码中获取了视频.但是我无法以mvvm模式中获取视频.

在xaml中用于按钮和图像控制:-

i am working on a project and need to stream video through mvvm pattern.i got video in code behind.but i can''t get video in mvvm pattern.

in xaml for button and image control :-

<Button Command="{Binding StartCommand}"  Content="Start" Grid.Row="4" Height="38"      Margin="9" Name="btnwebcamstart"  Width="{StaticResource btnWidth}"/>

<Image Source="{Binding Source=Imagevideo}"   Margin="9" Name="patientvideo" Stretch="Fill"  Width="120" Grid.RowSpan="2" Height="104" Grid.Row="1" />

我只是制作一个图片属性:

i just make one image property:

public Image Imagevideo
       {
           get
           {
               return imagevideo;
           }
           set
           {
               imagevideo = value;
               OnPropertyChaged("Imagevideo");
           }
       }

WebCam是一个.cs文件.
在构造函数中，我写道:-

WebCam is a .cs file .
in constructor i write:-

WebCam webcam=new webcam();
   webcam.InitializeWebCam(ref  Imagevideo);
   this.StartCommand = new DelegateCommand<object>(this.patientvideostart);
   }
   public void InitializeWebCam(ref System.Windows.Controls.Image ImageControl)
       {
           webcam = new WebCamCapture();
           webcam.FrameNumber = ((ulong)(0ul));
           webcam.TimeToCapture_milliseconds = FrameNumber;
           webcam.ImageCaptured += new WebCamCapture.WebCamEventHandler(webcam_ImageCaptured);
           _FrameImage = ImageControl;
       }
     void webcam_ImageCaptured(object source, WebcamEventArgs e)
       {
           _FrameImage.Source = LoadBitmap((System.Drawing.Bitmap)e.WebCamImage);
       }
    public static BitmapSource LoadBitmap(System.Drawing.Bitmap source)
       {

           ip = source.GetHbitmap();

           bs = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(ip, IntPtr.Zero, System.Windows.Int32Rect.Empty,

               System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());

           DeleteObject(ip);

           return bs;

       }

我只是从.cs文件调用一个启动方法

i just call one start method from .cs file

public void patientvideostart(object parameter)
       {

           webcam.Start();
       }

//webcam.InitializeWebCam(ref  Imagevideo);

在"ref imagevideo"后面的代码中是一个图像控件.我更改为属性"ref Imagevideo".因此在这里，我得到了错误.
属性，索引器或动态成员访问不能作为out或ref参数传递"

我如何才能在mvvm.advance中获得视频流.谢谢.

in code behind "ref imagevideo" is a image control .i changed to a property"ref Imagevideo".so in here i got the error.
"A property,indexer or dynamic member access may not be passed as an out or ref parameter"

what i can do for getting the video streaming in mvvm.advance thanks..

<pre lang="c#">

推荐答案

错误非常明显-您无法将属性传递给方法的ref参数.

您需要临时设置:

Hi,

The error is pretty clear - you can''t pass a property to a ref parameter of a method.

You need to make a temporary:

var circle = painting.Circles[mutationIndex];
MutatePosition(ref circle, painting.Width, painting.Height);
painting.Circles[mutationIndex] = circle;

话虽这么说，可变结构通常不是一个好主意.您可能要考虑使它成为类而不是结构.

请看以下CP文章:将YouTube API 1.9.0.0与MVVM-Light-Toolkit一起使用 [

That being said, mutable structs are often a bad idea. You might want to consider making this a class instead of a struct.

Have a look at the following CP article: Using YouTube API 1.9.0.0 with MVVM-Light-Toolkit[^] - it might shed some light on the issue.

Kind regards,

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