按下返回按钮后，listview会隐藏UI IOS

Posted 2021-04-25

按下后，屏幕键盘上的返回按钮列表视图隐藏在ios屏幕上。相同的代码在android上运行完美。我创建了30秒的视频，可以帮助您理解问题。代码文件和视频可以从这里下载https://drive.google.com/drive/folders/1Q4O1KexIHvrCX79AR3CesRXJRWM1o2JR?usp=sharing

<ListView x:Name="listViewOrder" ItemTapped="OnActivitySelected" HasUnevenRows="True">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                      <Frame   HasShadow="True" OutlineColor="Silver"   Padding="3">
                        <Grid BackgroundColor="{Binding RowColour}" ColumnSpacing="2" Padding="2">
                            <StackLayout Orientation="Horizontal" HeightRequest="35" BackgroundColor="{Binding RowColour}" Padding="10">
                                <StackLayout Spacing="0" BackgroundColor="{Binding RowColour}" Orientation="Horizontal" HorizontalOptions="Start">
                                    <Label FontSize="Medium" TextColor="#707070" Text="{Binding GFIELD3}" HorizontalOptions="StartAndExpand" VerticalOptions="Center"/>
                                </StackLayout>

                                <StackLayout Spacing="0" BackgroundColor="{Binding RowColour}" Orientation="Horizontal" HorizontalOptions="EndAndExpand">
                                    <Image Aspect="AspectFit" Source = "{Binding ImageStatus}" HorizontalOptions="StartAndExpand" VerticalOptions="Center" HeightRequest = "20" WidthRequest="20" />
                                </StackLayout>
                            </StackLayout>
                        </Grid>
                      </Frame>
                    </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>

<StackLayout x:Name="layoutForBluetooth" HeightRequest="200" Padding="5, 5, 5, 5" BackgroundColor="#5DCBEE" Orientation="Horizontal" HorizontalOptions="FillAndExpand">
                <Frame Padding="5,5,5,5" HorizontalOptions="FillAndExpand" OutlineColor="Black" HasShadow="True">
                    <Grid>
                        <Label Text="Scan Your Barcode" x:Name="lblDriverNumber" TextColor="Black" FontSize="Medium" HorizontalOptions="FillAndExpand" Margin="0,10" />
                        <Entry x:Name="txtentry" FontSize="Medium" TextColor="Black" WidthRequest="400" HorizontalOptions="FillAndExpand" VerticalOptions="CenterAndExpand"  />
                    </Grid>
                </Frame>

async void Txtentry_Completed(object sender, EventArgs e)
{
   BiendListview(orderID);
}

 public void BiendListview(int OID)
    {
        try
        {
            List<GenericFields> GN = new List<GenericFields>();
            GN = GetDeliveryOrderItems(OID);
            if (GN != null)
            {
               // listViewOrder.BeginRefresh();
                listViewOrder.ItemsSource = GN;
               // listViewOrder.EndRefresh();
            }
        }
        catch (Exception ex)
        {

        }
    }

答案

请设置断点来调试GN的值。从您的代码：

if (GN != null)
{
   // listViewOrder.BeginRefresh();
    listViewOrder.ItemsSource = GN;
   // listViewOrder.EndRefresh();
}

这个if语句总是正确的，因为你已经用GN构造了List<GenericFields> GN = new List<GenericFields>();。它永远不会为空。

您可以尝试将其修改为：

if (GN.Count != 0)
{
   // listViewOrder.BeginRefresh();
    listViewOrder.ItemsSource = GN;
   // listViewOrder.EndRefresh();
}