我正在使用模板10处理UWP应用程序,并且我无法在ViewModel中更改属性后更新UI。我试图在模型中实现Bindable基础,但仍然不起作用。
XAML:
<Page.DataContext>
<vm:RoomPageViewModel x:Name="ViewModel" />
</Page.DataContext>
<Grid x:Name="RoomProperties"
RelativePanel.Below="pageHeader"
RelativePanel.AlignLeftWithPanel="True">
<Grid.ColumnDefinitions>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
</Grid.RowDefinitions>
<Image Grid.Column="0" Width="220" Height="220" Stretch="Fill" Source="{x:Bind ViewModel.Room.Image}"></Image>
<TextBlock Grid.Column="1" FontSize="16" Text="{x:Bind ViewModel.Room.Name}"></TextBlock>
<TextBlock Grid.Column="0" Grid.Row="1" FontSize="16" Text="Room Type: "></TextBlock>
<TextBlock Grid.Column="1" Grid.Row="1" FontSize="16" Text="{x:Bind ViewModel.Room.Type}"></TextBlock>
<TextBlock Grid.Column="0" Grid.Row="2" FontSize="16" Text="Room Number: "></TextBlock>
<TextBlock Grid.Column="1" Grid.Row="2" FontSize="16" Text="{x:Bind ViewModel.Room.Number}"></TextBlock>
</Grid>
<ListView x:Name="SensorListView"
ItemsSource="{x:Bind ViewModel.Room.Sensors}"
IsEnabled="False"
RelativePanel.Below="RoomProperties"
RelativePanel.AlignLeftWithPanel="True">
<ListView.ItemTemplate>
<DataTemplate x:DataType="data:Sensor">
<StackPanel HorizontalAlignment="Left">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" FontSize="16" Text="{x:Bind Name}"></TextBlock>
<TextBlock Grid.Column="1" FontSize="16" Text="{x:Bind SensorValues[0].Value, Mode=TwoWay}"></TextBlock>
<TextBlock Grid.Column="2" FontSize="16" Text="{x:Bind Units}"></TextBlock>
</Grid>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
视图模型:
public class RoomPageViewModel : ViewModelBase
{
Template10.Services.SerializationService.ISerializationService _SerializationService;
private FileIOHelper.FileIOHelper fileIOHelper = new FileIOHelper.FileIOHelper();
private AppServiceConnection serialCommandService;
// This method is called by the Set accessor of each property.
// The CallerMemberName attribute that is applied to the optional propertyName
// parameter causes the property name of the caller to be substituted as an argument.
public RoomPageViewModel()
{
if (Windows.ApplicationModel.DesignMode.DesignModeEnabled)
{
Room = Room.CreateNewRoom();
}
}
private Room room = Room.CreateNewRoom();
public Room Room
{
get
{
return this.room;
}
set
{
Set(ref room, value);
}
}
public void UpdateRoom()
{
foreach (var sensor in Room.Sensors)
{
var sensorValue = new SensorValue();
sensorValue.Sensor = "R" + Room.Number + "D" + sensor.DeviceNumber + "S" + sensor.Type;
ObservableCollection<SensorValue> newList = fileIOHelper.ReadFromFile(sensorValue).ToObservableCollection();
SensorValue newSensorValue = newList.Last();
sensor.SensorValues = new ObservableCollection<SensorValue> { newSensorValue };
}
foreach (var actuator in Room.Actuators)
{
var actuatorValue = ActuatorValue.CreateNewActuatorValue();
actuatorValue.Actuator = "R" + Room.Number + "D" + actuator.DeviceNumber + "A" + actuator.Type;
ObservableCollection<ActuatorValue> newList = fileIOHelper.ReadFromFile(actuatorValue).ToObservableCollection();
ActuatorValue newActuatorValue = newList.Last();
actuator.ActuatorValues = new ObservableCollection<ActuatorValue> { newActuatorValue };
}
}
public async void RefreshButton_Click(object sender, object parameter)
{
Random rnd = new Random();
Room = Room.CreateNewRoom(rnd.Next(1, 9));
//UpdateRoom();
await Task.CompletedTask;
}
型号:
public class Room : BindableBase
{
private string name;
private string image;
private string type;
private int number;
public string Name
{
get
{
return name;
}
set
{
Set(ref name, value);
}
}
public string Image
{
get
{
return image;
}
set
{
Set(ref image, value);
}
}
public string Type
{
get
{
return type;
}
set
{
Set(ref type, value);
}
}
public int Number
{
get
{
return number;
}
set
{
Set(ref number, value);
}
}
private ObservableCollection<Sensor> sensors;
private ObservableCollection<Actuator> actuators;
public ObservableCollection<Sensor> Sensors
{
get
{
return sensors;
}
set
{
Set(ref sensors, value);
}
}
public ObservableCollection<Actuator> Actuators
{
get
{
return actuators;
}
set
{
Set(ref actuators, value);
}
}
public Room() {
Random rnd = new Random();
Name = "DefaultName";
Image = "DefaultImage";
Type = "DefaultType";
Number = rnd.Next(1,9);
Sensors = new ObservableCollection<Sensor>();
Actuators = new ObservableCollection<Actuator>();
}
public Room(int inputNumber)
{
Name = "DefaultName";
Image = "DefaultImage";
Type = "DefaultType";
Number = inputNumber;
Sensors = new ObservableCollection<Sensor>();
Actuators = new ObservableCollection<Actuator>();
}
public static Room CreateNewRoom(int inputNumber)
{
return new Room(inputNumber);
}
}
我将本指南用于实施文档(https://github.com/Windows-XAML/Template10/wiki/MVVM)。关于为什么UI没有得到更新的任何想法?感谢。
答案 0 :(得分:2)
大多数人(包括我自己)在习惯使用'旧'Binding
语法时经常犯的错误是x:Bind
将OneTime
绑定为默认值而不是OneWay
结合。
模式:指定绑定模式,作为以下字符串之一:“OneTime”,“OneWay”或“TwoWay”。默认为“OneTime”。请注意,这与{Binding}的默认值不同,在大多数情况下为“OneWay”。
来源:MSDN
您的绑定更新工作所需的是:
INotifyPropertyChanged
,由BindableBase
处理。设置正确的模式,例如
Text="{x:Bind ViewModel.Room.Number, Mode=OneWay}