Xamarin.forms Xamarin窗体，将新项动态添加到listview

我在internet上找不到一个解决方案，当单击按钮时，如何在Xamarin forms项目中向listview动态添加新项。我在互联网上得到的唯一东西就是如何从listview动态删除项目

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因此，请了解我如何在Xamarin表单中编写代码，以便在单击按钮时将新项动态添加到listview？

如果列表的ItemSource是ObservableCollection，则只需向集合中添加一项即可更新列表

ObservableCollection<string> data = new ObservableCollection<string>();

data.Add("a");
data.Add("b");
data.Add("c");

myListView.ItemSource = data;

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如果列表的ItemSource是ObservableCollection，只需向集合中添加一个项即可更新列表

ObservableCollection<string> data = new ObservableCollection<string>();

data.Add("a");
data.Add("b");
data.Add("c");

myListView.ItemSource = data;

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在MainPage.xaml.cs的代码behinde中，假设您有一个class Person

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

和

private ObservableCollection<Person> _persons;
public ObservableCollection<Person> Persons
{
    get
    {
        return _persons ?? (_persons = new ObservableCollection<Person>());
    }
}

MainPage.xaml页面如下所示：

private void Button_OnClicked(object sender, EventArgs e)
{
    //create person here 
    var person = new Person()
    {
        Name = "toumir",
        Age = 25
    };

    //add the created person to the list
    Persons.Add(person);
}

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:App2"
             x:Class="App2.MainPage">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <StackLayout Grid.Row="0">
            <Button Clicked="Button_OnClicked" Text="Add Person"/>
        </StackLayout>

        <ListView Grid.Row="1" ItemsSource="{Binding Persons}">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                         <StackLayout Margin="1">
                            <Label Text="{Binding Name}"/>
                            <Label Text="{Binding Age}"/>
                        </StackLayout>
                        <ViewCell.ContextActions>
                            <MenuItem Text="test"></MenuItem>
                        </ViewCell.ContextActions>
                        </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>
    </Grid>
</ContentPage>

---

在MainPage.xaml.cs的代码behinde中，假设您有一个班级人员

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

和

private ObservableCollection<Person> _persons;
public ObservableCollection<Person> Persons
{
    get
    {
        return _persons ?? (_persons = new ObservableCollection<Person>());
    }
}

MainPage.xaml页面如下所示：

private void Button_OnClicked(object sender, EventArgs e)
{
    //create person here 
    var person = new Person()
    {
        Name = "toumir",
        Age = 25
    };

    //add the created person to the list
    Persons.Add(person);
}

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:App2"
             x:Class="App2.MainPage">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <StackLayout Grid.Row="0">
            <Button Clicked="Button_OnClicked" Text="Add Person"/>
        </StackLayout>

        <ListView Grid.Row="1" ItemsSource="{Binding Persons}">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                         <StackLayout Margin="1">
                            <Label Text="{Binding Name}"/>
                            <Label Text="{Binding Age}"/>
                        </StackLayout>
                        <ViewCell.ContextActions>
                            <MenuItem Text="test"></MenuItem>
                        </ViewCell.ContextActions>
                        </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>
    </Grid>
</ContentPage>

但我发现，当列表或集合值在运行时更改时，有时UI上的ListView不会更新。我可以通过设置ItemSource=null，然后将ItemSource重新分配给列表来解决此问题。但我发现，有时当列表或集合值在运行时发生更改时，UI上的ListView不会更新。我可以通过设置ItemSource=null，然后将ItemSource重新分配给列表来解决这个问题。