feat: 添加图标大小限制和无缓存请求头，优化 WebView 加载逻辑

android/app/src/main/kotlin/io/openim/flutter/openim/MainActivity.kt

@@ -24,6 +24,7 @@ class MainActivity : FlutterActivity() {
     private val CHANNEL = "io.openim.flutter.openim/apk_info"
     private val SHELL_BRANDING_CHANNEL = "io.openim.flutter.im_webview_app/shell_branding"
     private val TAG = "MainActivity"
+    private val MAX_BRANDING_ICON_SIZE = 192
 
     override fun onCreate(savedInstanceState: android.os.Bundle?) {
         // 华为/荣耀/OPPO 等国产设备：在任意网络请求之前同步安装 Conscrypt，修复 SSL 握手失败（无 GMS 时系统 SSL 实现不完整）
@@ -115,13 +116,27 @@ class MainActivity : FlutterActivity() {
 
     private fun getCurrentAppIconDataUrl(): String {
         val icon = packageManager.getApplicationIcon(packageName)
-        val bitmap = drawableToBitmap(icon)
+        val bitmap = resizeBitmap(drawableToBitmap(icon), MAX_BRANDING_ICON_SIZE)
         val output = ByteArrayOutputStream()
         bitmap.compress(Bitmap.CompressFormat.PNG, 100, output)
         val base64 = Base64.encodeToString(output.toByteArray(), Base64.NO_WRAP)
         return "data:image/png;base64,$base64"
     }
 
+    private fun resizeBitmap(bitmap: Bitmap, maxSize: Int): Bitmap {
+        val width = bitmap.width
+        val height = bitmap.height
+        val longestSide = maxOf(width, height)
+        if (longestSide <= maxSize) {
+            return bitmap
+        }
+
+        val scale = maxSize.toFloat() / longestSide.toFloat()
+        val scaledWidth = (width * scale).toInt().coerceAtLeast(1)
+        val scaledHeight = (height * scale).toInt().coerceAtLeast(1)
+        return Bitmap.createScaledBitmap(bitmap, scaledWidth, scaledHeight, true)
+    }
+
     private fun drawableToBitmap(drawable: Drawable): Bitmap {
         if (drawable is BitmapDrawable && drawable.bitmap != null) {
             return drawable.bitmap

lib/main.dart

@@ -15,6 +15,11 @@ const _shellBackground = Color(0xFFF8FBFF);
 const _shellAccent = Color(0xFF0089FF);
 const _shellSubText = Color(0xFF8E9AB0);
 const _resumeCoverDuration = Duration(milliseconds: 700);
+const _noCacheHeaders = {
+  'Cache-Control': 'no-cache, no-store, max-age=0, must-revalidate',
+  'Pragma': 'no-cache',
+  'Expires': '0',
+};
 const _shellBrandingChannel =
     MethodChannel('io.openim.flutter.im_webview_app/shell_branding');
 const _shellMediaPermissionBridgeScript = r'''
@@ -221,7 +226,8 @@ class _H5ShellPageState extends State<H5ShellPage> with WidgetsBindingObserver {
       appName: widget.shellBranding.appName,
       appLogo: widget.shellBranding.appLogo,
     );
-    _controller = _buildController()..loadRequest(Uri.parse(_homeUrl));
+    _controller = _buildController();
+    unawaited(_loadHome());
   }
 
   @override
@@ -439,6 +445,27 @@ class _H5ShellPageState extends State<H5ShellPage> with WidgetsBindingObserver {
     return _runJavaScriptSafely(_stopWebMediaScript);
   }
 
+  Future<void> _loadHome() async {
+    if (mounted) {
+      setState(() {
+        _loadError = null;
+        _progress = 0;
+        _showShellCover = true;
+      });
+    }
+
+    try {
+      await _controller.clearCache();
+    } catch (_) {
+      // Some WebView implementations can reject cache operations during setup.
+    }
+
+    await _controller.loadRequest(
+      Uri.parse(_homeUrl),
+      headers: _noCacheHeaders,
+    );
+  }
+
   Future<NavigationDecision> _handleNavigationRequest(
     NavigationRequest request,
   ) async {
@@ -568,7 +595,7 @@ class _H5ShellPageState extends State<H5ShellPage> with WidgetsBindingObserver {
               if (_loadError != null)
                 _ErrorPanel(
                   message: _loadError!,
-                  onRetry: () => _controller.loadRequest(Uri.parse(_homeUrl)),
+                  onRetry: () => unawaited(_loadHome()),
                 ),
             ],
           ),