超链接按钮和 Json Uri

Question

在我的 UWP 应用程序中，我从 Json 文件解析文本图像和 URI，但是当我解析 URI 并在我的 xaml 页面中的超链接按钮中调用它时，没有任何反应。如果有人可以和我核对这段代码，请告诉我是否应该将字符串转换为 uri (Common_sense_media,metacritic) 或相反，或者告诉我如何使它工作

public sealed partial class MainPage : Page
{
    public MainPage()
    {
        this.InitializeComponent();
        jsonCall();
    }



    public static BitmapImage ImageFromRelativePath(FrameworkElement parent, string path)
    {
        var uri = new Uri(parent.BaseUri, path);
        BitmapImage result = new BitmapImage();
        result.UriSource = uri;
        return result;
    }





    public async void jsonCall()
    {
        List<Result> listResult = new List<Result>();

        var client = new HttpClient();
        String jsonString = await client.GetStringAsync(new Uri("http://api-public.guidebox.com/v1.43/Tunisia/rKgEWJbFg0kgEHrcGXPKhPDo0XtTafyC/movies/all/250/250"));
        System.Diagnostics.Debug.WriteLine(JsonValue.Parse(jsonString).ValueType);
        JsonObject root = JsonValue.Parse(jsonString).GetObject();
        JsonArray res = root.GetNamedArray("results");

        for (uint i = 0; i < res.Count; i++)
        {
            JsonObject con = res.GetObjectAt(i);
            String id = con.GetNamedNumber("id").ToString();
            String title = con.GetNamedString("title");
            string release_year = con.GetNamedNumber("release_year").ToString();
            string themoviedb = con.GetNamedNumber("themoviedb").ToString();
            string original_title = con.GetNamedString("original_title");
            JsonArray alt = con.GetNamedArray("alternate_titles");
            String name = "-";
            if (alt.Count != 0) { 
            name = alt.GetStringAt(0);
            for (uint j = 1; j < alt.Count; j++)
            {
                name = name + ", " + alt.GetStringAt(j);
            }
            }
            string imdb = con.GetNamedString("imdb");
            string pre_order = con.GetNamedBoolean("pre_order").ToString();
            string in_theaters = con.GetNamedBoolean("in_theaters").ToString();
            string release_date = con.GetNamedString("release_date");
            string rating = con.GetNamedString("rating");
            string rottentomatoes = con.GetNamedNumber("rottentomatoes").ToString();
            string freebase = con.GetNamedString("freebase");
            string wikipedia_id = con.GetNamedNumber("wikipedia_id").ToString();
            //System.Diagnostics.Debug.WriteLine("------------------------------"+con.GetNamedValue("metacritic").ValueType);

            // string metacritic = con.GetNamedString("metacritic");
            //     MediaElement metacritic= VideoFromRelativePath(this, con.GetNamedValue("metacritic").ValueType.ToString());
            string common_sense_media = con.GetNamedValue("common_sense_media").ToString();
            string metacritic = con.GetNamedValue("metacritic").ToString();

           // Uri Common_sense_media = con.GetNamedValue("Common_sense_media").ToString();
            //   string Common_sense_media = con.GetNamedValue("Common_sense_media").ToString();
            //string Common_sense_media = con.GetNamedString("metacritic");
            //System.Diagnostics.Debug.WriteLine("-------------"+Common_sense_media);
            BitmapImage Poster_120x171 = ImageFromRelativePath(this, con.GetNamedString("poster_120x171"));
            BitmapImage poster_240x342 = ImageFromRelativePath(this, con.GetNamedString("poster_240x342"));
            BitmapImage poster_400x570 = ImageFromRelativePath(this, con.GetNamedString("poster_400x570"));
            list.Items.Add(new Result {Id=id,Title=title,Themoviedb=themoviedb,Original_title=original_title,Alternate_titles=name,
               Imdb=imdb,Pre_order=pre_order,In_theaters=in_theaters,Release_date=release_date,
               Rating=rating, Rottentomatoes=rottentomatoes,Freebase=freebase,Wikipedia_id=wikipedia_id,

                Common_sense_media = common_sense_media,
                Metacritic= metacritic,
                Poster = Poster_120x171, Poster_240x342=poster_240x342,Poster_400x570=poster_400x570});


        }

    }
}
}

我的xaml代码：

 <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <ListView
        Name="list"
        DataContext="{Binding}">
        <ListView.ItemTemplate>
            <DataTemplate>
                <StackPanel
                    HorizontalAlignment="Stretch"
                    VerticalAlignment="Stretch"
                    Orientation="Vertical">

                    <Image Source="{Binding Poster}" Width="100" Height="100"/>
                    <TextBlock
                        Name="id"
                        Text="{Binding Id}" />

                    <TextBlock
                        Name="title"
                        Text="{Binding Title}" />

                    <TextBlock
                        Name="release_year"
                        Text="{Binding Release_year}" />
                    <TextBlock
                        Name="themoviedb"
                        Text="{Binding Themoviedb}" />
                    <TextBlock
                        Name="original_title"
                        Text="{Binding Original_title}" />
                    <TextBlock
                        Name="alternate_titles"
                        Text="{Binding Alternate_titles}" />
                    <TextBlock
                        Name="imdb"
                        Text="{Binding Imdb}" />
                    <TextBlock
                        Name="pre_order"
                        Text="{Binding Pre_order}" />
                    <TextBlock
                        Name="in_theaters"
                        Text="{Binding In_theaters}" />
                    <TextBlock
                        Name="release_date"
                        Text="{Binding Release_date}" />
                    <HyperlinkButton Content="Common_sense_media" NavigateUri= "{Binding Common_sense_media}"/>
                    <HyperlinkButton Content="metacritic" NavigateUri= "{Binding metacritic}"/>
                    <TextBlock
                        Name="rating"
                        Text="{Binding Rating}" />
                    <TextBlock
                        Name="rottentomatoes"
                        Text="{Binding Rottentomatoes}" />
                    <TextBlock
                        Name="freebase"
                        Text="{Binding Freebase}" />
                    <TextBlock
                        Name="wikipedia_id"
                        Text="{Binding Wikipedia_id}" />

                    <TextBlock
                        Name="common_sense_media"
                        Text="{Binding Common_sense_media}" />
                    <TextBlock
                        Name="poster_120x171"
                        Text="{Binding Poster_120x171}" />
                    <Image Source="{Binding Poster_240x342}" Width="100" Height="100"/>
                    <Image Source="{Binding Poster_400x570}" Width="100" Height="100"/>





                </StackPanel>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>



</Grid>

Answer 1

HyperLinkButton 的给定字符串格式不正确 URL。双引号（ "" ）被添加到字符串的每一端。所以如果你注意到你得到 BindingExpressionError(Error: Converter failed to convert value of type 'Windows.Foundation.String' to type 'Uri'; BindingExpression: Path='Common_sense_media' DataItem='test1.Result, test1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'; target element is 'Windows.UI.Xaml.Controls.HyperlinkButton' (Name='null'); target property is 'NavigateUri' (type 'Uri'). )

使用 Newtonsoft.Json 包进行 JSON 解析。它具有 JsonPropertyAttribute，允许您指定 Json 属性的名称，指示 Newtonsoft.Json.JsonSerializer 始终序列化具有指定名称的成员。这是 tutorial 的 link。您只需将 [JsonProperty(keyname)] 添加到所有属性。库将反序列化 json 给你只需一行代码 Result resu = Newtonsoft.Json.JsonConvert.DeserializeObject<Result>(con.ToString())

这里是简化的配对码

      public class Result
            {
                //public string Alternate_titles { get; set; }
                //public string Common_sense_media { get; set; }
                //public string Freebase { get; set; }
                //public string Id { get; set; }
                //public string Imdb { get; set; }
                //public string In_theaters { get; set; }
                //public string Metacritic { get; set; }
                //public string Original_title { get; set; }
                //public BitmapImage Poster { get; set; }
                //public BitmapImage Poster_240x342 { get; set; }
                //public BitmapImage Poster_400x570 { get; set; }
                //public string Pre_order { get; set; }
                //public string Rating { get; set; }
                //public string Release_date { get; set; }
                //public string Rottentomatoes { get; set; }
                //public string Themoviedb { get; set; }
                //public string Title { get; set; }
                //public string Wikipedia_id { get; set; }
    //declare all above properties like below using JsonProperty
                [JsonProperty("common_sense_media")]
                public string Common_sense_media
                {
                    get; set;

                }
          [JsonProperty("poster_120x171")]
         public string Poster { get; set; }
        [JsonProperty("poster_240x342")]
        public string Poster_240x342 { get; set; }
        [JsonProperty("poster_400x570")]
        public string Poster_400x570 { get; set; }
            }


    public async void jsonCall()
            {
                List<Result> listResult = new List<Result>();

                var client = new HttpClient();
                String jsonString = await client.GetStringAsync(new Uri("http://api-public.guidebox.com/v1.43/Tunisia/rKgEWJbFg0kgEHrcGXPKhPDo0XtTafyC/movies/all/250/250"));
                System.Diagnostics.Debug.WriteLine(JsonValue.Parse(jsonString).ValueType);
                JsonObject root = JsonValue.Parse(jsonString).GetObject();
                JsonArray res = root.GetNamedArray("results");

                for (uint i = 0; i < res.Count; i++)
                {
                   JsonObject con = res.GetObjectAt(i);
                    Result resu =         Newtonsoft.Json.JsonConvert.DeserializeObject<Result>(con.ToString());
                          list.Items.Add(resu);
                }
         }

Answer 2

因为你得到的common_sense_media值像"\"https://www.commonsensemedia.org/movie-reviews/magic-mike\""一样在开头和结尾包含额外的双引号。所以你应该使用 Trim 删除它们，更改代码如下

string common_sense_media = con.GetNamedValue("common_sense_media").ToString().TrimStart('"').TrimEnd('"');
string metacritic = con.GetNamedValue("metacritic").ToString().TrimStart('"').TrimEnd('"');

更新后部分链接仍然无法访问，这是因为您的common_sense_media和metacritic的httprequest的return结果为空。对于这种情况，请按您的意愿处理。你可以简单判断

if(common_sense_media==null || metacritic==null)
{
  //Do what you want do deal with them, such as give a default link  
}

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