Question

我有以下代码：

Using reader As XmlReader = XmlReader.Create(New StringReader(xmlString))
    reader.ReadToFollowing("GridChannel")
    Dim Channel As String = reader.GetAttribute("Channel")
    Dim DisplayName As String = reader.GetAttribute("DisplayName")

    reader.ReadToFollowing("Airings")

    While reader.ReadToFollowing("GridAiring")
        Dim Title As String = reader.GetAttribute("Title")
        Dim EpisodeTitle As String = reader.GetAttribute("EpisodeTitle")
        Dim AiringTDurationime As String = reader.GetAttribute("AiringTDurationime")
        Dim isHD As Boolean = Convert.ToBoolean(reader.GetAttribute("isHD"))
        Dim TVRating As String = reader.GetAttribute("TVRating")
    End While

    reader.MoveToElement()
    reader.ReadToFollowing("ImageGrid")
    Dim ImageUrl As String = reader.GetAttribute("ImageUrl")

End Using

我的XML看起来像这样：

<GetGridScheduleResult xmlns="http://api.rovicorp.com/v9/listings" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" Locale="en-US" ServiceId="5122" Name="Cityhere - Comcast" StartDate="2013-04-12T14:18:24.2054325Z" Duration="240">
<GridChannels>
  <GridChannel ServiceId="890138" SourceId="1280" Order="20002" Channel="2" CallLetters="WGNAMER" DisplayName="WGNAMER" SourceLongName="WGN America" Type="24-Hours" SourceType="Basic" ParentNetworkId="0" IconAvailable="false" IsChannelOverride="false" SourceAttributes="0">
    <ChannelSchedules/>
    <SourceAttributeTypes/>
    <Airings>
        <GridAiring ProgramId="35951" SeriesId="3490" Title="Matlock" EpisodeTitle="Santa Claus" AiringTime="2013-04-12T14:00:00Z" Duration="60" Color="Color" AiringType="Unknown" CC="true" LetterBox="false" Stereo="false" HD="false" SAP="false" TVRating="TV-PG" Dolby="false" DSS="false" HDLevel="HD Level Unknown" DVS="false" Category="Other" Subcategory="drama" Sports="false"/>
        <GridAiring ProgramId="828869" SeriesId="1409" Title="In the Heat of the Night" EpisodeTitle="Hatton's Turn" AiringTime="2013-04-12T15:00:00Z" Duration="60" Color="Color" AiringType="Unknown" CC="true" LetterBox="false" Stereo="false" HD="false" SAP="false" TVRating="TV-PG@V" Dolby="false" DSS="false" HDLevel="HD Level Unknown" DVS="false" Category="Other" Subcategory="crime drama" Sports="false"/>
        <GridAiring ProgramId="978338" SeriesId="1409" Title="In the Heat of the Night" EpisodeTitle="Hatton's Turn" AiringTime="2013-04-12T16:00:00Z" Duration="60" Color="Color" AiringType="Unknown" CC="true" LetterBox="false" Stereo="false" HD="false" SAP="false" TVRating="TV-PG@V" Dolby="false" DSS="false" HDLevel="HD Level Unknown" DVS="false" Category="Other" Subcategory="crime drama" Sports="false"/>
        <GridAiring ProgramId="4210626" Title="WGN Midday News" AiringTime="2013-04-12T17:00:00Z" Duration="60" Color="Color" AiringType="New" CC="true" LetterBox="false" Stereo="true" HD="false" SAP="false" TVRating="None" Dolby="false" DSS="false" HDLevel="HD Level Unknown" DVS="false" Category="News" Subcategory="newscast" Sports="false"/>
        <GridAiring ProgramId="878716" SeriesId="1028666" Title="Walker, Texas Ranger" EpisodeTitle="El Coyote, Part 2" AiringTime="2013-04-12T18:00:00Z" Duration="60" Color="Color" AiringType="Unknown" CC="true" LetterBox="false" Stereo="true" HD="false" SAP="false" TVRating="TV-14@V" Dolby="false" DSS="false" HDLevel="HD Level Unknown" DVS="false" Category="Other" Subcategory="crime drama" Sports="false"/>
    </Airings>
    <ChannelImages>
        <ImageGrid ImageUrl="http://cps-static.rovicorp.com/2/Open/TV%20Guide%20Widget%20Logos/WGN_2010.png" ImageId="427700" ImageTitle="WGN America" ImageCaption="Widget Logo" ObjectId="1280" ObjectName="WGN America" ImageCreditDisplay="false" ImageType="Station Logo" ImageHorizontalResolution="92" ImageVerticalResolution="36" ImageFormatId="0" AspectRatio="5:2" ParentImageId="16818227">
            <ObjectType>Source</ObjectType>
            <ImageFormat xsi:nil="true"/>
            <ImageExpiryDateTime xsi:nil="true"/>
            <LastUpdate>2012-01-24T15:20:46.453Z</LastUpdate>
        </ImageGrid>
    </ChannelImages>
  </GridChannel>
  etc etc...
</GridChannels>
</GetGridScheduleResult>

我在 ImageUrl 中获得 Nothing 作为值。为了深入了解该元素并获取这些值，我缺少什么？

Answer 1

那是因为跟循环：

While reader.ReadToFollowing("GridAiring")
    Dim Title As String = reader.GetAttribute("Title")
    Dim EpisodeTitle As String = reader.GetAttribute("EpisodeTitle")
    Dim AiringTDurationime As String = reader.GetAttribute("AiringTDurationime")
    Dim isHD As Boolean = Convert.ToBoolean(reader.GetAttribute("isHD"))
    Dim TVRating As String = reader.GetAttribute("TVRating")
End While

在找到最后一个GridAiring元素后将文件读取到最后。

试试：

Using reader As XmlReader = XmlReader.Create(New StreamReader("Input.txt"))
    reader.ReadToFollowing("GridChannel")
    Dim Channel As String = reader.GetAttribute("Channel")
    Dim DisplayName As String = reader.GetAttribute("DisplayName")

    reader.ReadToFollowing("Airings")

    While reader.Read() AndAlso Not reader.NodeType = XmlNodeType.Element
    End While

    While reader.Name = "GridAiring"
        Dim Title As String = reader.GetAttribute("Title")
        Dim EpisodeTitle As String = reader.GetAttribute("EpisodeTitle")
        Dim AiringTDurationime As String = reader.GetAttribute("AiringTDurationime")
        Dim isHD As Boolean = Convert.ToBoolean(reader.GetAttribute("isHD"))
        Dim TVRating As String = reader.GetAttribute("TVRating")

        reader.ReadToNextSibling("GridAiring")
    End While

    reader.MoveToElement()
    reader.ReadToFollowing("ImageGrid")
    Dim ImageUrl As String = reader.GetAttribute("ImageUrl")

End Using

从响应中获取XML元素

1 个答案: