[Windows] WebView2 Initialization Failed: HRESULT(0x80070005) Access Denied (composeApp:run)

[Oriental-Serenity]

When running the project with ./gradlew :composeApp:run on Windows, the application crashes immediately during WebView2 component initialization with a permission denied error (HRESULT 0x80070005). This blocks the core functionality of the WebView component in the app.

Steps to Reproduce
Environment: Windows 11
Execute command: gradlew :composeApp:run

Exception in thread "AWT-EventQueue-0" io.github.kdroidfilter.webview.wry.WebViewException$WryException: v1=WebView2 error: WindowsError(Error { code: HRESULT(0x80070005), message: " Access Denied." })
at io.github.kdroidfilter.webview.wry.FfiConverterTypeWebViewError.read-MhnMXUE(composewebview_wry.jvm.kt:2058)
at io.github.kdroidfilter.webview.wry.FfiConverterTypeWebViewError.read-MhnMXUE(composewebview_wry.jvm.kt:2047)
at io.github.kdroidfilter.webview.wry.FfiConverter.liftFromRustBuffer(composewebview_wry.jvm.kt:222)
at io.github.kdroidfilter.webview.wry.Composewebview_wry_jvmKt.createWebview-R4QgNNg(composewebview_wry.jvm.kt:2798)
at io.github.kdroidfilter.webview.wry.NativeBindings.createWebview-gnehgXw(WryWebViewPanel.kt:706)
at io.github.kdroidfilter.webview.wry.WryWebViewPanel.createIfNeeded(WryWebViewPanel.kt:351)

[Oriental-Serenity]

I have analyzed and fixed the WebView2 permission error issue on Windows. Below is the solution:

Problem Cause

WebView2 encounters a permission error (HRESULT: 0x80070005, "Access Denied") when attempting to create or access files on Windows. This occurs because the WebView dataDirectory is null by default, causing WebView2 to try storing data in a directory without write permissions.

Fix Solution

I modified the file demo-shared/src/commonMain/kotlin/io/github/kdroidfilter/webview/demo/App.kt and set a writable temporary directory as the dataDirectory for WebView2:

1. Modify WebViewState initialization: When creating WebViewState, set a unique path based on the system temporary directory for desktopWebSettings.dataDirectory.
2. Add necessary imports: Add the import for java.io.File to support file path operations.

Specific Changes

• File: demo-shared/src/commonMain/kotlin/io/github/kdroidfilter/webview/demo/App.kt
• Changes:
  • Added to the WebViewState initialization block:

    // Set a writable data directory to avoid WebView2 permission errors on Windows
    desktopWebSettings.dataDirectory = System.getProperty("java.io.tmpdir")?.let {
        it + File.separator + "composewebview" + File.separator + System.currentTimeMillis()
    }

  • Added import:

    import java.io.File

How It Works

This fix resolves the issue in the following ways:

1. Uses System.getProperty("java.io.tmpdir") to get the system temporary directory, which all users have write permissions for.
2. Creates a unique subdirectory under the temp directory (using a timestamp to ensure uniqueness).
3. Sets this directory as WebView2's data directory, ensuring WebView2 can safely store its data.