适配iOS读取沙盒文件，iOS使用webView 读取沙盒文件时需要在路径前添加file://

lib/pages/read_web/controller.dart

@@ -696,9 +696,13 @@ class ReadController extends FullLifeCycleController with GetSingleTickerProvide
     await file.writeAsString(htmlStr);
 
     localHtml5Path = writeFilePath;
+    String url = writeFilePath;
+    if(Platform.isIOS){
+      url = 'file://$writeFilePath';
+    }
     webViewController.loadUrl(urlRequest: URLRequest(
       // url: Uri.parse(writeFilePath),
-        url: WebUri.uri(Uri.parse(writeFilePath))
+        url: WebUri.uri(Uri.parse(url))
     ));
 
     final result = await SqlManager.updateReadHistoryByBookId(int.parse(bookId), int.parse(chapterId));