Question

点击十字图像时，我需要删除所选的图片。为此，我在图像上方添加了十字图像并添加了点击事件。我正在android.telecom.Connection中显示图像。

MainPage.xaml

FlowListView

MainPage.xaml.cs

<flv:FlowListView FlowColumnCount="3" x:Name="listItems" 
                    SeparatorVisibility="None"
                    HasUnevenRows="false" RowHeight="100" >
            <flv:FlowListView.FlowColumnTemplate>
                <DataTemplate >
                    <StackLayout
                Orientation="Vertical">

                        <Image 
                    Source="ic_close.png"
                    HeightRequest="20"
                            ClassId="{Binding .}"
                    WidthRequest="20">
                            <Image.GestureRecognizers>
                                <TapGestureRecognizer
                        Tapped="RemoveImage"
                        NumberOfTapsRequired="1" />
                            </Image.GestureRecognizers>
                        </Image>

                        <Image AbsoluteLayout.LayoutFlags="All" HeightRequest="100" AbsoluteLayout.LayoutBounds="0,0,1,1" Source="{Binding .}"  Aspect="AspectFill" HorizontalOptions="FillAndExpand">
                        </Image>
                    </StackLayout>
                </DataTemplate>
            </flv:FlowListView.FlowColumnTemplate>
        </flv:FlowListView>

有人，请提出一种从FlowListview中删除该图像的方法吗？

Answer 1

首先，将您的收藏集设为ObservableCollection

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

第二，将图像名称添加到否则未使用的ClassID属性中

<Image ClassID="{Binding .}" ... />

最后，在您的RemoveImage

中

public void RemoveImage(Object sender, EventArgs args)
{
    var i = (Image)sender;
    images.Remove(i.ClassID);
}

Answer 2

创建一个ObservableCollection并在接收这些图像时将其添加到其中

喜欢这个：

protected override void OnAppearing()
    {
        base.OnAppearing(); :) 

        MessagingCenter.Subscribe<App, List<string>>((App)Xamarin.Forms.Application.Current, "ImagesSelected", (s, images) =>
        {
            for (int i =0;i< images.Count;i++)
            {
                _images.Add(images[i]);
            }
            listItems.FlowItemsSource = _images;
        });
    }

然后在点击图像后删除该选定图像。

public void RemoveImage(Object sender, EventArgs args)
{
    Image image = sender as Image;
    string obj = image.BindingContext as string;
    _images.Remove(obj);
}

Xamarin形式：如何从FlowListView中删除所选项目？

2 个答案: