[Blazor] Slow startup and navigation when debugging

[daniel-p-tech]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Hi,

After migrating my project from .NET 6 to .NET 7, there is a noticeably slower startup time of the app in Debug environment. Navigation back to the previous page using the browser back button is occasionally also much slower - sometimes there is up to a 3 second delay before the navigation event fires. As far as I can tell there is no problem with the published app.

Thank you!

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

.NET 7

Anything else?

Microsoft Visual Studio Community 2022 (64-bit), Version 17.4.3

[surayya-MS]

Thanks for contacting us. Please let us know whether this is Blazor WebAssembly.

Hi @daniel-p-tech. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[daniel-p-tech]

This is Blazor WASM.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

Tagging subscribers to 'arch-wasm': @lewing
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Hi,

After migrating my project from .NET 6 to .NET 7, there is a noticeably slower startup time of the app in Debug environment. Navigation back to the previous page using the browser back button is occasionally also much slower - sometimes there is up to a 3 second delay before the navigation event fires. As far as I can tell there is no problem with the published app.

Thank you!

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

.NET 7

Anything else?

Microsoft Visual Studio Community 2022 (64-bit), Version 17.4.3

Author:	daniel-p-tech
Assignees:	-
Labels:	arch-wasm
Milestone:	-

Tagging subscribers to this area: @thaystg
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Hi,

After migrating my project from .NET 6 to .NET 7, there is a noticeably slower startup time of the app in Debug environment. Navigation back to the previous page using the browser back button is occasionally also much slower - sometimes there is up to a 3 second delay before the navigation event fires. As far as I can tell there is no problem with the published app.

Thank you!

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

.NET 7

Anything else?

Microsoft Visual Studio Community 2022 (64-bit), Version 17.4.3

Author:	daniel-p-tech
Assignees:	-
Labels:	arch-wasm, area-Debugger-mono
Milestone:	-

[FOtto28]

Have the same problem with Blazor WASM since upgrade from .net 6 to .net 7

[dev-jlb]

Same issue here. The initial startup time for a sample app went from ~25s to 55s. In the output it gets to "Loaded xx.xx MB resources from cache" and then pauses for a long duration. At least with my app, I narrowed it down to Microsoft.AspNetCore.Components.WebAssembly.DevServer. If I use one of the 6.x versions, everything is fine, but when I update it to 7.0.x I see the slow behavior.

I'm not an expert on browser dev tools, but if I check the Network tab, it looks like it is getting stuck here for 15+s: browserLinkSignalR/connect?transport=webSockets&connectionToken=xxxxxxxxxxx