vb.net - .ToString错误(vb.net)

Question

由于某种原因，这对我不起作用，我不确定。我正在尝试为我的Web浏览器设置“设置主页”按钮，这是检查是否设置了页面，然后转到页面的代码:

    Dim HomepageInfo As String
    If IO.File.Exists(Environment.SpecialFolder.ApplicationData & "\Homepage.Info") = True Then
        HomepageInfo = IO.File.ReadAllText(Environment.SpecialFolder.ApplicationData & "\Homepage.Info")
        WebBrowser1.Url = HomepageInfo.ToString
    Else
        'Create a File with a Default Homepage (www.google.com)
        IO.File.WriteAllText(Environment.SpecialFolder.ApplicationData & "\Homepage.Info", "www.google.com")
    End If

并且这显示为错误:HomepageInfo.ToString，错误是:“类型'String'的值不能转换为'System.Uri'。”

谢谢你的帮助!

Answer 1

WebBrowser.Url 属性接受uri对象而不是字符串:

Property Value Type: System.Uri A Uri representing the URL of the current document.

因此，您必须使用 Uri 类的实例:

Provides an object representation of a uniform resource identifier (URI) and easy access to the parts of the URI.

码:

Dim HomepageInfo As String
If IO.File.Exists(Environment.SpecialFolder.ApplicationData & "\Homepage.Info") = True Then
    HomepageInfo = IO.File.ReadAllText(Environment.SpecialFolder.ApplicationData & "\Homepage.Info")
    WebBrowser1.Url = New Uri(HomepageInfo.ToString)
Else
    'Create a File with a Default Homepage (www.google.com)
    IO.File.WriteAllText(Environment.SpecialFolder.ApplicationData & "\Homepage.Info", "www.google.com")
End If