数据绑定不会更新属性更改(UWP)
问题描述:
我正在开发使用c#和通用Windows平台(UWP)的应用程序,并且正努力在布局控件和可观察类之间创建单向数据绑定。目前,当observable类属性发生更改时,它不会更新UI元素。我认为这与我绑定DataTemplate ListViewItem而不是静态布局元素有关,但我不确定这是问题还是如何解决。任何帮助,将不胜感激。显示UI元素和后端代码的代码。数据绑定不会更新属性更改(UWP)
的DataTemplate(XAML)(造型为可读性移除)
<DataTemplate x:Key="variableTemplate"
x:DataType="local:VariableNode">
<Border>
<StackPanel Orientation="Vertical">
<Border>
<Grid>
<TextBlock Text="{Binding Name}" />
<StackPanel Orientation="Horizontal" >
<Button Tag="{Binding Description}"/>
<Button Tag="{Binding}"/>
</StackPanel>
</Grid>
</Border>
<Grid Margin="0, 10">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
</Grid.ColumnDefinitions>
<Border >
<Grid Grid.Column="0">
<Button Click="Choose_Measurement"
Tag="{Binding}">
<StackPanel Orientation="Vertical">
<TextBlock Text="{x:Bind Path=Measurement_Name, Mode=TwoWay}"
Foreground="{x:Bind MF}" />
<TextBlock Foreground="{x:Bind MF}" />
</StackPanel>
</Button>
</Grid>
</Border>
<Grid Grid.Column="1">
<Button Foreground="{Binding UF}"
Tag="{Binding}"
IsEnabled="{Binding Unit_Exists}"
Click="Choose_Unit">
<StackPanel Orientation="Vertical">
<TextBlock Text="{x:Bind Path=Unit_Name, Mode=OneWay}"
Foreground="{Binding UF}" />
<TextBlock Foreground="{Binding UF}" />
</StackPanel>
</Button>
</Grid>
</Grid>
</StackPanel>
</Border>
</DataTemplate>
C#可观察类VariableNode(不相关属性移除)
public class VariableNode : ExperimentNode
{
public VariableNode() { }
public VariableNode(VariableType type)
{
Type = type;
Name = name_ref[(int)Type];
Category = "Problem";
Unit = -1;
}
private string[] name_ref = { "Independent Variable", "Dependent Variable", "Controlled Variable" };
public enum VariableType { Independent, Dependent, Controlled };
public VariableType Type { get; set; }
public Measurement Measure { get; set; }
public int Unit { get; set; }
[XmlIgnoreAttribute]
public Measurement MeasureSource
{
get { return this.Measure; }
set
{
this.Measure = value;
OnPropertyChanged("Measurement_Name");
}
}
[XmlIgnoreAttribute]
public string Measurement_Name
{
get
{
if (Measure == null) { return "Select a Measurement"; }
else { return Measure.Name; }
}
set
{
if (Measure != null)
{
Measure.Name = value;
OnPropertyChanged();
}
}
}
[XmlIgnoreAttribute]
public string Unit_Name
{
get
{
if (Measure == null) { return "No measurement"; }
else if (Unit < 0) { return "Select a unit"; }
else { return Measure.Unit[Unit]; }
}
}
[XmlIgnoreAttribute]
public bool Unit_Exists
{
get { return Measure != null; }
}
}
C#XAML.CS代码调用的属性变化
public void Choose_Measurement (object sender, RoutedEventArgs e)
{
Button butt = sender as Button
VariableNode sel = butt.Tag as VariableNode;
sel.Measurement_Name = "New Name";
}
再次感谢您的帮助,我知道它的很多代码,我很赞赏e帮助调试/学习。
答
好了,我最终找到了答案,我认为它可以帮助其他人试图复制什么,我试图做的:
基本上类,一个是试图使可观测必须扩展类INotifyPropertyChanged
。所以,我最终使从基类的所有我的观察类的扩展从:
public class BaseClass : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged = delegate { };
protected void OnPropertyChanged(PropertyChangedEventArgs e)
{
PropertyChanged(this, e);
}
protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
}
}
'(...)绑定一个DataTemplate ListViewItem的而不是静态的布局元素(...)'这应该不是问题。是否显示其他绑定(例如“{绑定描述}”)?你有尝试切换'绑定:绑定''绑定'(请参阅这里为什么这可能很重要:http://*.com/questions/33070705/with-compiled-bindings-xbind-why-do-i-have-to -call-绑定更新) –