Null Reference Exception on start up

[dan-toadllc]

I'm getting a NullReferenceException error on this line in Form1.Designer.cs:

this.Controls.Add(this.webView21);

I don't see anything that is null.

AB#26932580

[mikemeinz]

@dan-toadllc

I had problem similar (if not the same) as yours. It turned out that the directives in the NuGet package don't specify that the the WebView2Loader.dll should be included. Maybe my solution will help you.

I modified the two Microsoft.Web.WebView2.targets files in the NuGet package so that the ClickOnce (Publish) feature of Visual Studio would copy the WebView2Loader.dll to the AppPublish directory. I changed None to Content and Include to Included. This has been reported as a bug in Issue 228.

Before

<ItemGroup>
    <None Include="$(MSBuildThisFileDirectory)$(EffectivePlatform)\WebView2Loader.dll">
      <Link>%(Filename)%(Extension)</Link>
      <PublishState>Include</PublishState>
      <Visible>False</Visible>
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
  </ItemGroup>

After

  <ItemGroup>
    <Content Include="$(MSBuildThisFileDirectory)$(EffectivePlatform)\WebView2Loader.dll">
      <Link>%(Filename)%(Extension)</Link>
      <PublishState>Included</PublishState>
      <Visible>False</Visible>
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </Content>
  </ItemGroup>

[champnic]

@dan-toadllc Could you try @mikemeinz change above and see if that fixes it? If so, we'll fix this as part of #228.

[champnic]

@dan-toadllc We haven't heard back in a month so I'm closing this for now. If you are still running into this issue please reactivate and we'll take another look. Thanks!

[alexlogiclab]

This is definitely an issue. I am not sure where you make the changes you have suggested mikemeinz....

I really want to use this control but it seems very tricky to get running at the moment. Any help would be greatly appreciated :-)

[mikemeinz]

@alexbitsnz

On my PC, there are two files named Microsoft.Web.WebView2.targets. One of them is in C:\Users\USERNAME\.nuget\packages\microsoft.web.webview2\0.9.538-prerelease\build\native. The other file is in C:\Users\USERNAME\.nuget\packages\microsoft.web.webview2\0.9.538-prerelease\build. I used Windows Explorer Search to find them.

I made the same edit in both files. See Jun 12 post above.

[alexlogiclab]

Thank you Mike, that helped a lot :-)

[champnic]

@alexbitsnz Glad @mikemeinz 's fix helped. We're tracking that issue in #228.