javascript - UWP WebView Javascript "Object doesn' t 支持属性或方法”

Question

我需要在 UWP (Windows 10) WebView 中使用 JavaScript 来调用 C# 方法。我按照有关如何使用 AddWebAllowedObject 的说明进行操作，但是当 JavaScript 调用 C# 函数时，出现此 javascript 错误:

0x800a01b6 - JavaScript runtime error: Object doesn't support property or method 'getAppVersion'

如您在 javascript 中所见，“window.SCObject”是一个有效对象，但“window.SCObject.getAppVersion()”会引发错误!知道为什么吗？

这是我的 C# 代码:

namespace Test
{
    [AllowForWeb]
    public sealed class HtmlCommunicator
    {
        public string getAppVersion()
        {
            PackageVersion version = Package.Current.Id.Version;
            return String.Format("{0}.{1}.{2}.{3}",
                                 version.Major, version.Minor, version.Build, version.Revision);
        }
    }


    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
            this.HtmlWebView.Navigate(new Uri("ms-appx-web:///Assets/HTMLPage1.html"));
        }

        private HtmlCommunicator communicationWinRT = new HtmlCommunicator();
        private void HtmlWebView_NavigationStarting(WebView sender, WebViewNavigationStartingEventArgs args)
        {
            this.HtmlWebView.AddWebAllowedObject("SCObject", communicationWinRT);
        }
    }
}

这是我的 XAML:

<Page
x:Class="Test.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Test"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <WebView NavigationStarting="HtmlWebView_NavigationStarting" x:Name="HtmlWebView" />
</Grid>

这是我的 Javascript:

<script type="text/javascript">
    function HtmlGetAppVersion() {
        if (window.SCObject) { //this is true
            var version = window.SCObject.getAppVersion(); //error occurs here
            console.log("Version: " + version);
        }
    }
</script>

谢谢。

Answer 1

我看到在同一个项目中定义了HtmlCommunicator，是不行的。

您需要创建一个单独的 windows 通用 windows 运行时组件项目。

MSDN文档也提到了这一点:

The object passed into AddWebAllowedObject(System.String,System.Object) must be imported from a Windows Runtime component that is separate from the app assembly. This is necessary for the AllowForWeb attribute to be property identified by the WebView security subsystem. If you use a class from your app project, AddWebAllowedObject(System.String,System.Object) does not work.

我已帮助您在单独的 Windows 运行时组件中进行测试。效果很好。