具有联接表和选取器循环的结构表

Question

我有 2 个关于表和选取器的问题：

1. 如何像这张图片一样使用连接表来构建此表？

2. 假设我有 3 名学生。如果实现，如何编写循环命令将选择器值获取到 Table？picker valuecolectionviewloopAbsensi

我在 中创建了一个如下数据集合。xaml

<CollectionView Margin="-15"   
                x:Name="AbsenList"   
                SelectionMode="Single"   
                VerticalOptions="CenterAndExpand">  
    <CollectionView.ItemTemplate>  
        <DataTemplate>  
            <StackLayout Orientation="Horizontal">  
                <Image Source="{Binding StudentImage}"/>  
                <Label Text="{Binding Name}"/>  
                <Picker Title="Absen" SelectedItem="{Binding Checklist}">  
                    <Picker.ItemsSource>  
                        <x:Array Type="{x:Type x:String}">  
                            <x:String>A</x:String>  
                            <x:String>B</x:String>  
                            <x:String>C</x:String>  
                            <x:String>D</x:String>  
                        </x:Array>  
                    </Picker.ItemsSource>  
                </Picker>  
            </StackLayout>  
        </DataTemplate>  
    </CollectionView.ItemTemplate>  
</CollectionView>  
<Button Text="Save" Clicked="SaveToDatabase"/>  

如果有人回答这个问题，谢谢:)

Note：此问题总结整理于: Structure Table with Joined Table and Picker Loop

Answer 1

你好

欢迎来到我们的 Microsoft 问答平台！

如果实现，如何编写循环命令将选择器值获取到 Absensi 表？

您可以在物料模型类中创建一个属性来存储所选数据，也可以将所选数据传递给事件中的属性。SelectedIndexChanged

您可以参考以下代码：

    <CollectionView ItemsSource="{Binding Monkeys}" VerticalOptions="Start">  
        <CollectionView.ItemTemplate>  
            <DataTemplate>  
                <Grid Padding="3">  
                    <Grid.RowDefinitions>  
                        <RowDefinition Height="Auto" />  
                        <RowDefinition Height="Auto" />  
                    </Grid.RowDefinitions>  
                    <Grid.ColumnDefinitions>  
                        <ColumnDefinition Width="1*" />  
                        <ColumnDefinition Width="1*" />  
                        <ColumnDefinition Width="1*" />  
                    </Grid.ColumnDefinitions>  
                    <Image Grid.RowSpan="2"   
                           Source="{Binding ImageUrl}"   
                           Aspect="AspectFill"  
                           HeightRequest="60"   
                           WidthRequest="60" />  
                    <Label Grid.Column="1"   
                           Text="{Binding Name}"   
                           FontAttributes="Bold" />  
                    <Label Grid.Row="1"  
                           Grid.Column="1"   
                           Text="{Binding Location}"  
                           FontAttributes="Italic"   
                           VerticalOptions="End" />  

                  <Picker Title="Absen" Grid.RowSpan="2" Grid.Column="2" SelectedItem="{Binding Checklist}"  SelectedIndexChanged="Picker_SelectedIndexChanged">  
                        <Picker.ItemsSource>  
                            <x:Array Type="{x:Type x:String}">  
                                <x:String>A</x:String>  
                                <x:String>B</x:String>  
                                <x:String>C</x:String>  
                                <x:String>D</x:String>  
                            </x:Array>  
                        </Picker.ItemsSource>  
                    </Picker>  
                </Grid>  
            </DataTemplate>  
        </CollectionView.ItemTemplate>  
    </CollectionView>  

在项目模型中添加字段清单（我的项目是 Monkey)

public class Monkey: INotifyPropertyChanged  
{
private string _Name;
public string Name
{
set { SetProperty(ref _Name, value); }
get { return _Name; }
} // add field Checklist
private string _checklist;
public string Checklist {
set { SetProperty(ref _checklist, value); }
get { return _checklist; }
}


 public string Location { get; set; }  
 public string Details { get; set; }  
 public string ImageUrl { get; set; }  


 bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)  
 {  
     if (Object.Equals(storage, value))  
         return false;  

     storage = value;  
     OnPropertyChanged(propertyName);  
     return true;  
 }  

 protected void OnPropertyChanged([CallerMemberName] string propertyName = null)  
 {  
     PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));  
 }  

 public event PropertyChangedEventHandler PropertyChanged;  
}

在文件 yourpage.xaml.cs 公共部分类中实现事件 SelectedIndexChanged ContentPage

{
public VerticalListPage()
{
InitializeComponent();
BindingContext = new MonkeysViewModel();
}


 private void Picker_SelectedIndexChanged(object sender, System.EventArgs e)  
 {  
     var picker = sender as Picker;  

     var index = picker.SelectedIndex;  
     var list = picker.ItemsSource;  

     var model = picker.BindingContext as Monkey;  
     model.Checklist = (string)list[index];  
 }  
}

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