Warning: file_get_contents(/data/phpspider/zhask/data//catemap/2/csharp/321.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
C# 为什么我不能将项目添加到数据库?_C#_Xaml_Windows Phone 8.1_Sqlite Net - Fatal编程技术网

C# 为什么我不能将项目添加到数据库?

C# 为什么我不能将项目添加到数据库?,c#,xaml,windows-phone-8.1,sqlite-net,C#,Xaml,Windows Phone 8.1,Sqlite Net,我使用SQLite net创建了一个数据库,然后以以下方式在其中插入一个对象: SQLiteAsyncConnection conn = new SQLiteAsyncConnection(Path.Combine(ApplicationData.Current.LocalFolder.Path, "Database.db"), true); await conn.CreateTableAsync<Musei>(); Musei musPref;

我使用SQLite net创建了一个数据库,然后以以下方式在其中插入一个对象:

SQLiteAsyncConnection conn = new SQLiteAsyncConnection(Path.Combine(ApplicationData.Current.LocalFolder.Path, "Database.db"), true);
await conn.CreateTableAsync<Musei>();

            Musei musPref;
            musPref = new Musei
                {
                    DidascaliaLista=muss.DidascaliaLista,
                    NomeMuseo = muss.NomeMuseo,
                    Luogopreciso = muss.Luogopreciso,
                    Descrizione = muss.Descrizione,
                    NumeroTel = muss.NumeroTel,
                    IndirizzoEmail = muss.IndirizzoEmail,
                    Immagine= muss.Immagine,
                };



await conn.InsertAsync(musPref);
在新页面中,我希望检索数据库中ListView元素中显示的数据库

这是代码c:

SQLiteAsyncConnection conn = new SQLiteAsyncConnection(Path.Combine(ApplicationData.Current.LocalFolder.Path, "Database.db"), true);
await conn.CreateTableAsync<Musei>();
var Dbase = Path.Combine(ApplicationData.Current.LocalFolder.Path, "Database.db");
var con = new SQLiteAsyncConnection(Dbase, true);

var query = await con.Table<Musei>().ToListAsync();
ListaPreferiti.Source = query;
这是代码XAML:

<Page.Resource>
<CollectionViewSource x:Name="ListaPreferiti" IsSourceGrouped="True"/>
</Page.Resource>
.....
<ListView x:Name="ListPreferiti" ItemsSource="{Binding Source={StaticResource ListaPreferiti}}" IsItemClickEnabled="True" ItemClick="ListPreferiti_ItemClick" Margin="0,-1,0.667,-0.333">
                                <ListView.ItemTemplate>
                                    <DataTemplate>
                                        <Grid>
                                            <Grid.ColumnDefinitions>
                                                <ColumnDefinition Width="15"/>
                                                <ColumnDefinition Width="5"/>
                                                <ColumnDefinition Width="30"/>
                                                <ColumnDefinition Width="*"/>
                                            </Grid.ColumnDefinitions>
                                            <Grid.RowDefinitions>
                                                <RowDefinition Height="30"/>
                                                <RowDefinition Height="30"/>
                                                <RowDefinition Height="30"/>
                                                <RowDefinition Height="10"/>
                                            </Grid.RowDefinitions>

                                            <Image x:Name="Cerchio" Grid.Column="0" Grid.Row="0" Source="Assets/120.png" Width="15" Height="15" VerticalAlignment="Top" Margin="0,13,0,0"/>

                                            <TextBlock Grid.Column="3" Grid.Row="0" Text="{Binding NomeMuseo}" TextWrapping="Wrap" FontSize="24" FontWeight="Bold"/>
                                            <TextBlock Grid.Column="3" Grid.Row="2" Text="{Binding Descrizione}" TextWrapping="Wrap" FontSize="18"/>
                                            <Image Grid.Column="2" Grid.Row="0" Source="Assets/NoImage.png"/>
                                            <TextBlock Grid.Column="3" Grid.Row="1" FontSize="18" Text="{Binding Luogopreciso}"/>
                                        </Grid>
                                    </DataTemplate>
                                </ListView.ItemTemplate>
                                <ListView.GroupStyle>
                                    <GroupStyle HidesIfEmpty="True">
                                        <GroupStyle.HeaderTemplate>
                                            <DataTemplate>
                                                <Grid Background="Chocolate">
                                                    <TextBlock Text="{Binding Key}" Foreground="Beige" 
                                                   Style="{StaticResource HeaderTextBlockStyle}"/>
                                                </Grid>
                                            </DataTemplate>
                                        </GroupStyle.HeaderTemplate>
                                    </GroupStyle>
                                </ListView.GroupStyle>
                            </ListView>
                        </PivotItem>
                    </Pivot>
                </Grid>
            </PivotItem>
        </Pivot>
我不明白为什么ListView是空的。只要尝试启动应用程序,调试Visual Studio的输出就会显示以下消息:


错误:BindingExpression路径错误:在“App1.Musei,App1,Version=1.0.0,Culture=neutral,PublicKeyToken=null”上找不到“Key”属性。BindingExpression:Path='Key'DataItem='App1.Musei,App1,Version=1.0.0,Culture=neutral,PublicKeyToken=null';目标元素是“Windows.UI.Xaml.Controls.TextBlock”Name='null';目标属性是“Text”类型的“String”

您的表中没有名为Key的字段,因此它告诉您它无法绑定到它,因为它找不到Key属性。你想用那个文本块做什么?我错了,我改成了:``现在我不再犯那个错误了,但我总是看到空列表。请显示你的可观察属性。