fix(app): webview Preference is given to the page background color

src/platforms/app-plus/service/api/plugin/uts.js

-import { isPlainObject, hasOwn, extend, capitalize, isString } from 'uni-shared';
-
+import { isPlainObject, hasOwn, extend, capitalize, isStr as isString } from 'uni-shared';
+
 let callbackId = 1;
 let proxy;
 const callbacks = {};
@@ -279,6 +279,6 @@ function requireUTSPlugin(name) {
         console.error(`${name} is not found`);
     }
     return define;
-}
-
-export { initUTSClassName, initUTSIndexClassName, initUTSPackageName, initUTSProxyClass, initUTSProxyFunction, normalizeArg, registerUTSInterface, registerUTSPlugin, requireUTSPlugin };
+}
+
+export { initUTSClassName, initUTSIndexClassName, initUTSPackageName, initUTSProxyClass, initUTSProxyFunction, normalizeArg, registerUTSInterface, registerUTSPlugin, requireUTSPlugin };

src/platforms/app-plus/service/framework/webview/parser/webview-style-parser.js

@@ -44,13 +44,15 @@ export function parseWebviewStyle (id, path, _routeOptions = {}) {
     }
   })
 
-  const backgroundColor = routeOptions.window.backgroundColor
+  let backgroundColor = routeOptions.window.backgroundColor
   if (
     /^#[a-z0-9]{6}$/i.test(backgroundColor) ||
     backgroundColor === 'transparent'
   ) {
     if (!webviewStyle.background) {
       webviewStyle.background = backgroundColor
+    } else {
+      backgroundColor = webviewStyle.background
     }
     if (!webviewStyle.backgroundColorTop) {
       webviewStyle.backgroundColorTop = backgroundColor