如何通过mvvm在viewmodel中显示selecteditem从列表视图到xamarin中的条目的数据?

问题描述

我正在通过xamarin中的SQLite进行粗操作，但是我想显示从列表视图到条目的数据，以便我可以更新它，但是我不知道如何调用绑定在xaml中的选定项

i am doing crud operation through SQLite in xamarin but i want to show data from listview to entry so that i can update it but i don't know how to call selected item that is binded in xaml

    <ListView  ItemsSource="{Binding companylist}" SelectedItem="{Binding selectedname}" >
        <ListView.ItemTemplate>
            <DataTemplate>
                <ViewCell>
                    <Label Text="{Binding name}"/>
                </ViewCell>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>
    <StackLayout>

        <Entry Text="{Binding id}" IsVisible="False"/>
        <Entry Placeholder="Name" Text="{Binding name}"/>
        <Button Text="Update" Command="{Binding UpdateCompanyCommand}"/>
    </StackLayout>
</StackLayout>

视图模型中的代码是

 public Command UpdateCompanyCommand { get; }
    async Task UpdateCompany()
    {
        var db = new SQLiteConnection(dbpath);
        Company company = new Company()
        {
            id=id,

            name = Name


        };
        db.Update(company);
        await Xamarin.Forms.Application.Current.MainPage.DisplayAlert("Message", "Name is Updated", "Ok");

    }

推荐答案

您可以通过将您的name属性绑定到带有ListView的SelectedItem的Entry中来实现，如下所示，

You can achieve it through binding your name property into Entry with SelectedItem of ListView like below,

<Entry Text="{Binding name}" 
       BindingContext="{Binding SelectedItem, Source={x:Reference listView}}" />

为ListView输入一个名称，并通过所选项目设置Entry的BindingContext.每当列表视图所选项目更改时，条目就会更新.

Put a name for ListView and set BindingContext of Entry by your selected item. The entry will be updated whenever the listview selected item changed.

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