包含项目更改时触发的 ObservableCollection
ObservableCollection that fires when containing items change
我发现这个话题对这里的很多人来说都是一场真正的斗争,因此实际上涵盖得很好!尽管如此,none 所提供的解决方案似乎对我有用。
正如标题所说,这是关于 ObservableCollection 在项目的值发生变化时不会触发的问题,只有当项目 本身 以某种方式被删除、添加或更改时.
我尝试了使用 BindingList 的解决方案 - 尽管很多人反对它 - 但它没有用,解释了扩展 ObservableCollections 的解决方案 here。 None 它似乎有效...这留下了问题是错误是在我认为的地方还是在其他地方!!
好的,这是我的代码:
基类:
public class ModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propName = "")
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
}
}
class TestSensor : ModelBase
{
private bool isOnline;
public bool IsOnline
{
get
{
return isOnline;
}
set
{
if (isOnline != value)
{
isOnline = value;
this.OnPropertyChanged();
}
}
}
private double sensorDatauStrain;
public double SensorDatauStrain
{
get { return sensorDatauStrain; }
set
{
if (sensorDatauStrain != value)
{
sensorDatauStrain = value;
this.OnPropertyChanged();
}
}
}
private double sensorDatakNewton;
public double SensorDatakNewton
{
get { return sensorDatakNewton; }
set
{
if (sensorDatakNewton != value)
{
sensorDatakNewton = value;
this.OnPropertyChanged();
}
}
}
private double sensorDataTon;
public double SensorDataTon
{
get { return sensorDataTon; }
set
{
if (sensorDataTon != value)
{
sensorDataTon = value;
this.OnPropertyChanged();
}
}
}
private double sensorDatausTon;
public double SensorDatausTon
{
get { return sensorDatausTon; }
set
{
if (sensorDatausTon != value)
{
sensorDatausTon = value;
this.OnPropertyChanged();
}
}
}
private string sensorName;
public string SensorName
{
get { return sensorName; }
set
{
if (sensorName != value)
{
sensorName = value;
this.OnPropertyChanged();
}
}
}
public TestSensor(string name, double ustrain,double kNewton, double ton, double uston)
{
this.SensorName = name;
this.SensorDatauStrain = ustrain;
this.SensorDatakNewton = kNewton;
this.SensorDataTon = ton;
this.SensorDatausTon = uston;
this.IsOnline = true;
}
}
然后我有一个 class 包含这些传感器:
class Holm : ModelBase
{
public Holm(String Name, TestSensor sensor1, TestSensor sensor2)
{
Sensor1 = sensor1;
Sensor2 = sensor2;
this.Name = Name;
}
private string name;
public string Name
{
get
{
return name;
}
set
{
if (name != value)
{
name = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor1;
public TestSensor Sensor1
{
get
{
return sensor1;
}
set
{
if (sensor1 != value)
{
sensor1 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor2;
public TestSensor Sensor2
{
get
{
return sensor2;
}
set
{
if (sensor2 != value)
{
sensor2 = value;
this.OnPropertyChanged();
}
}
}
public bool IsOnline
{
get
{
if (!Sensor1.IsOnline || !Sensor2.IsOnline)
{
return false;
}
else
{
return true;
}
}
}
}
最后是包含我失败的 ObservableCollection 的 ViewModel - 排除了一些不相关的东西:
class MainViewViewModel : ModelBase
{
public ItemsChangeObservableCollection<Holm> HolmList { get;set;}
public MainViewViewModel()
{
Sensor11 = new TestSensor("Sensor 1.1", 0, 0, 0, 0);
Sensor12 = new TestSensor("Sensor 1.2", 0, 0, 0, 0);
Sensor21 = new TestSensor("Sensor 2.1", 0, 0, 0, 0);
Sensor22 = new TestSensor("Sensor 2.2", 0, 0, 0, 0);
Sensor31 = new TestSensor("Sensor 3.1", 0, 0, 0, 0);
Sensor32 = new TestSensor("Sensor 3.2", 0, 0, 0, 0);
Sensor41 = new TestSensor("Sensor 4.1", 0, 0, 0, 0);
Sensor42 = new TestSensor("Sensor 4.2", 0, 0, 0, 0);
Holm1 = new Holm("Holm 1", Sensor11, Sensor12);
Holm2 = new Holm("Holm 2", Sensor21, Sensor22);
Holm3 = new Holm("Holm 3", Sensor31, Sensor32);
Holm4 = new Holm("Holm 4", Sensor41, Sensor42);
HolmList = new ItemsChangeObservableCollection<Holm>();
HolmList.Add(Holm1);
HolmList.Add(Holm2);
HolmList.Add(Holm3);
HolmList.Add(Holm4);
}
private TestSensor sensor11;
public TestSensor Sensor11
{
get { return sensor11; }
set
{
if (sensor11 != value)
{
sensor11 = value;
this.OnPropertyChanged();
this.OnPropertyChanged("Holm1");
this.OnPropertyChanged("HolmList");
}
}
}
private TestSensor sensor12;
public TestSensor Sensor12
{
get { return sensor12; }
set
{
if (sensor12 != value)
{
sensor12 = value;
this.OnPropertyChanged();
this.OnPropertyChanged("Holm1");
this.OnPropertyChanged("HolmList");
}
}
}
private TestSensor sensor21;
public TestSensor Sensor21
{
get { return sensor21; }
set
{
if (sensor21 != value)
{
sensor21 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor22;
public TestSensor Sensor22
{
get { return sensor22; }
set
{
if (sensor22 != value)
{
sensor22 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor31;
public TestSensor Sensor31
{
get { return sensor31; }
set
{
if (sensor31 != value)
{
sensor31 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor32;
public TestSensor Sensor32
{
get { return sensor32; }
set
{
if (sensor32 != value)
{
sensor32 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor41;
public TestSensor Sensor41
{
get { return sensor41; }
set
{
if (sensor41 != value)
{
sensor41 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor42;
public TestSensor Sensor42
{
get { return sensor42; }
set
{
if (sensor42 != value)
{
sensor42 = value;
this.OnPropertyChanged();
}
}
}
private Holm holm1;
public Holm Holm1
{
get
{
return holm1;
}
set
{
if (holm1 != value)
{
holm1 = value;
this.OnPropertyChanged();
this.OnPropertyChanged("HolmList");
}
}
}
private Holm holm2;
public Holm Holm2
{
get
{
return holm2;
}
set
{
if (holm2 != value)
{
holm2 = value;
this.OnPropertyChanged();
}
}
}
private Holm holm3;
public Holm Holm3
{
get
{
return holm3;
}
set
{
if (holm3 != value)
{
holm3 = value;
this.OnPropertyChanged();
}
}
}
private Holm holm4;
public Holm Holm4
{
get
{
return holm4;
}
set
{
if (holm4 != value)
{
holm4 = value;
this.OnPropertyChanged();
}
}
}
}
Xaml 不是很重要,还没有完成。到目前为止,我已经用这段代码解决了这个问题:
<CheckBox Content="Sensor1.1" IsChecked="{Binding HolmList[0].Sensor1.IsOnline}"/>
<TextBlock Text="{Binding HolmList[0].Sensor1.IsOnline, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"/>
<CheckBox Content="Sensor1.2" IsChecked="{Binding HolmList[0].Sensor2.IsOnline}"/>
<TextBlock Text="{Binding HolmList[0].Sensor2.IsOnline, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"/>
<TextBlock Text="{Binding HolmList[0].IsOnline, UpdateSourceTrigger=PropertyChanged}" />
我只想让 Holms IsOnline-Property 在其中一个传感器 IsOnline-Property 变为假时立即变为假...但它不会!
我知道这是很多代码,但我实际上不确定错误位于何处。
另外:在我看来,我的 classed 对 OnPropertyChange() 进行了冗余调用...但我不确定。
我真的很感谢在这方面的各种帮助!!!
你的意思是这样的?
public class EnhancedObservableCollection<T> : ObservableCollection<T>
where T : INotifyPropertyChanged
{
public EnhancedObservableCollection(bool isCollectionChangedOnChildChange)
{
IsCollectionChangedOnChildChange = isCollectionChangedOnChildChange;
}
public EnhancedObservableCollection(List<T> list, bool isCollectionChangedOnChildChange) : base(list)
{
IsCollectionChangedOnChildChange = isCollectionChangedOnChildChange;
}
public EnhancedObservableCollection(IEnumerable<T> collection, bool isCollectionChangedOnChildChange) : base(collection)
{
IsCollectionChangedOnChildChange = isCollectionChangedOnChildChange;
}
public bool IsCollectionChangedOnChildChange { get; set; }
public event EventHandler<string> ChildChanged;
protected override void RemoveItem(int index)
{
var item = Items[index];
item.PropertyChanged -= ItemOnPropertyChanged;
base.RemoveItem(index);
}
private void ItemOnPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs)
{
var handler = ChildChanged;
if (handler != null)
{
handler(this, propertyChangedEventArgs.PropertyName);
}
if (IsCollectionChangedOnChildChange)
{
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace));
}
}
protected override void InsertItem(int index, T item)
{
base.InsertItem(index, item);
item.PropertyChanged += ItemOnPropertyChanged;
}
}
您绑定到 HolmList[0].IsOnline
的 TextBlock 没有更新,因为 IsOnline
在 Holm
上没有通知它的值已更改。
您可以在 TestSensor
中监听 TestSensor
的 PropertyChanged
事件,并在 TestSensor
的 IsOnline
之一发生变化时通知 IsOnline
属性 ] 属性变化。
class Holm : ModelBase
{
public Holm(String Name, TestSensor sensor1, TestSensor sensor2)
{
Sensor1 = sensor1;
Sensor2 = sensor2;
this.Name = Name;
Sensor1.PropertyChanged += OnSensorOnlineChanged;
Sensor2.PropertyChanged += OnSensorOnlineChanged;
}
private void OnSensorOnlineChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == "IsOnline")
{
OnPropertyChanged(nameof(IsOnline));
}
}
}
我发现这个话题对这里的很多人来说都是一场真正的斗争,因此实际上涵盖得很好!尽管如此,none 所提供的解决方案似乎对我有用。
正如标题所说,这是关于 ObservableCollection 在项目的值发生变化时不会触发的问题,只有当项目 本身 以某种方式被删除、添加或更改时.
我尝试了使用 BindingList 的解决方案 - 尽管很多人反对它 - 但它没有用,解释了扩展 ObservableCollections 的解决方案 here。 None 它似乎有效...这留下了问题是错误是在我认为的地方还是在其他地方!!
好的,这是我的代码:
基类:
public class ModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propName = "")
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
}
}
class TestSensor : ModelBase
{
private bool isOnline;
public bool IsOnline
{
get
{
return isOnline;
}
set
{
if (isOnline != value)
{
isOnline = value;
this.OnPropertyChanged();
}
}
}
private double sensorDatauStrain;
public double SensorDatauStrain
{
get { return sensorDatauStrain; }
set
{
if (sensorDatauStrain != value)
{
sensorDatauStrain = value;
this.OnPropertyChanged();
}
}
}
private double sensorDatakNewton;
public double SensorDatakNewton
{
get { return sensorDatakNewton; }
set
{
if (sensorDatakNewton != value)
{
sensorDatakNewton = value;
this.OnPropertyChanged();
}
}
}
private double sensorDataTon;
public double SensorDataTon
{
get { return sensorDataTon; }
set
{
if (sensorDataTon != value)
{
sensorDataTon = value;
this.OnPropertyChanged();
}
}
}
private double sensorDatausTon;
public double SensorDatausTon
{
get { return sensorDatausTon; }
set
{
if (sensorDatausTon != value)
{
sensorDatausTon = value;
this.OnPropertyChanged();
}
}
}
private string sensorName;
public string SensorName
{
get { return sensorName; }
set
{
if (sensorName != value)
{
sensorName = value;
this.OnPropertyChanged();
}
}
}
public TestSensor(string name, double ustrain,double kNewton, double ton, double uston)
{
this.SensorName = name;
this.SensorDatauStrain = ustrain;
this.SensorDatakNewton = kNewton;
this.SensorDataTon = ton;
this.SensorDatausTon = uston;
this.IsOnline = true;
}
}
然后我有一个 class 包含这些传感器:
class Holm : ModelBase
{
public Holm(String Name, TestSensor sensor1, TestSensor sensor2)
{
Sensor1 = sensor1;
Sensor2 = sensor2;
this.Name = Name;
}
private string name;
public string Name
{
get
{
return name;
}
set
{
if (name != value)
{
name = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor1;
public TestSensor Sensor1
{
get
{
return sensor1;
}
set
{
if (sensor1 != value)
{
sensor1 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor2;
public TestSensor Sensor2
{
get
{
return sensor2;
}
set
{
if (sensor2 != value)
{
sensor2 = value;
this.OnPropertyChanged();
}
}
}
public bool IsOnline
{
get
{
if (!Sensor1.IsOnline || !Sensor2.IsOnline)
{
return false;
}
else
{
return true;
}
}
}
}
最后是包含我失败的 ObservableCollection 的 ViewModel - 排除了一些不相关的东西:
class MainViewViewModel : ModelBase
{
public ItemsChangeObservableCollection<Holm> HolmList { get;set;}
public MainViewViewModel()
{
Sensor11 = new TestSensor("Sensor 1.1", 0, 0, 0, 0);
Sensor12 = new TestSensor("Sensor 1.2", 0, 0, 0, 0);
Sensor21 = new TestSensor("Sensor 2.1", 0, 0, 0, 0);
Sensor22 = new TestSensor("Sensor 2.2", 0, 0, 0, 0);
Sensor31 = new TestSensor("Sensor 3.1", 0, 0, 0, 0);
Sensor32 = new TestSensor("Sensor 3.2", 0, 0, 0, 0);
Sensor41 = new TestSensor("Sensor 4.1", 0, 0, 0, 0);
Sensor42 = new TestSensor("Sensor 4.2", 0, 0, 0, 0);
Holm1 = new Holm("Holm 1", Sensor11, Sensor12);
Holm2 = new Holm("Holm 2", Sensor21, Sensor22);
Holm3 = new Holm("Holm 3", Sensor31, Sensor32);
Holm4 = new Holm("Holm 4", Sensor41, Sensor42);
HolmList = new ItemsChangeObservableCollection<Holm>();
HolmList.Add(Holm1);
HolmList.Add(Holm2);
HolmList.Add(Holm3);
HolmList.Add(Holm4);
}
private TestSensor sensor11;
public TestSensor Sensor11
{
get { return sensor11; }
set
{
if (sensor11 != value)
{
sensor11 = value;
this.OnPropertyChanged();
this.OnPropertyChanged("Holm1");
this.OnPropertyChanged("HolmList");
}
}
}
private TestSensor sensor12;
public TestSensor Sensor12
{
get { return sensor12; }
set
{
if (sensor12 != value)
{
sensor12 = value;
this.OnPropertyChanged();
this.OnPropertyChanged("Holm1");
this.OnPropertyChanged("HolmList");
}
}
}
private TestSensor sensor21;
public TestSensor Sensor21
{
get { return sensor21; }
set
{
if (sensor21 != value)
{
sensor21 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor22;
public TestSensor Sensor22
{
get { return sensor22; }
set
{
if (sensor22 != value)
{
sensor22 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor31;
public TestSensor Sensor31
{
get { return sensor31; }
set
{
if (sensor31 != value)
{
sensor31 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor32;
public TestSensor Sensor32
{
get { return sensor32; }
set
{
if (sensor32 != value)
{
sensor32 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor41;
public TestSensor Sensor41
{
get { return sensor41; }
set
{
if (sensor41 != value)
{
sensor41 = value;
this.OnPropertyChanged();
}
}
}
private TestSensor sensor42;
public TestSensor Sensor42
{
get { return sensor42; }
set
{
if (sensor42 != value)
{
sensor42 = value;
this.OnPropertyChanged();
}
}
}
private Holm holm1;
public Holm Holm1
{
get
{
return holm1;
}
set
{
if (holm1 != value)
{
holm1 = value;
this.OnPropertyChanged();
this.OnPropertyChanged("HolmList");
}
}
}
private Holm holm2;
public Holm Holm2
{
get
{
return holm2;
}
set
{
if (holm2 != value)
{
holm2 = value;
this.OnPropertyChanged();
}
}
}
private Holm holm3;
public Holm Holm3
{
get
{
return holm3;
}
set
{
if (holm3 != value)
{
holm3 = value;
this.OnPropertyChanged();
}
}
}
private Holm holm4;
public Holm Holm4
{
get
{
return holm4;
}
set
{
if (holm4 != value)
{
holm4 = value;
this.OnPropertyChanged();
}
}
}
}
Xaml 不是很重要,还没有完成。到目前为止,我已经用这段代码解决了这个问题:
<CheckBox Content="Sensor1.1" IsChecked="{Binding HolmList[0].Sensor1.IsOnline}"/>
<TextBlock Text="{Binding HolmList[0].Sensor1.IsOnline, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"/>
<CheckBox Content="Sensor1.2" IsChecked="{Binding HolmList[0].Sensor2.IsOnline}"/>
<TextBlock Text="{Binding HolmList[0].Sensor2.IsOnline, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"/>
<TextBlock Text="{Binding HolmList[0].IsOnline, UpdateSourceTrigger=PropertyChanged}" />
我只想让 Holms IsOnline-Property 在其中一个传感器 IsOnline-Property 变为假时立即变为假...但它不会!
我知道这是很多代码,但我实际上不确定错误位于何处。 另外:在我看来,我的 classed 对 OnPropertyChange() 进行了冗余调用...但我不确定。
我真的很感谢在这方面的各种帮助!!!
你的意思是这样的?
public class EnhancedObservableCollection<T> : ObservableCollection<T>
where T : INotifyPropertyChanged
{
public EnhancedObservableCollection(bool isCollectionChangedOnChildChange)
{
IsCollectionChangedOnChildChange = isCollectionChangedOnChildChange;
}
public EnhancedObservableCollection(List<T> list, bool isCollectionChangedOnChildChange) : base(list)
{
IsCollectionChangedOnChildChange = isCollectionChangedOnChildChange;
}
public EnhancedObservableCollection(IEnumerable<T> collection, bool isCollectionChangedOnChildChange) : base(collection)
{
IsCollectionChangedOnChildChange = isCollectionChangedOnChildChange;
}
public bool IsCollectionChangedOnChildChange { get; set; }
public event EventHandler<string> ChildChanged;
protected override void RemoveItem(int index)
{
var item = Items[index];
item.PropertyChanged -= ItemOnPropertyChanged;
base.RemoveItem(index);
}
private void ItemOnPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs)
{
var handler = ChildChanged;
if (handler != null)
{
handler(this, propertyChangedEventArgs.PropertyName);
}
if (IsCollectionChangedOnChildChange)
{
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace));
}
}
protected override void InsertItem(int index, T item)
{
base.InsertItem(index, item);
item.PropertyChanged += ItemOnPropertyChanged;
}
}
您绑定到 HolmList[0].IsOnline
的 TextBlock 没有更新,因为 IsOnline
在 Holm
上没有通知它的值已更改。
您可以在 TestSensor
中监听 TestSensor
的 PropertyChanged
事件,并在 TestSensor
的 IsOnline
之一发生变化时通知 IsOnline
属性 ] 属性变化。
class Holm : ModelBase
{
public Holm(String Name, TestSensor sensor1, TestSensor sensor2)
{
Sensor1 = sensor1;
Sensor2 = sensor2;
this.Name = Name;
Sensor1.PropertyChanged += OnSensorOnlineChanged;
Sensor2.PropertyChanged += OnSensorOnlineChanged;
}
private void OnSensorOnlineChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == "IsOnline")
{
OnPropertyChanged(nameof(IsOnline));
}
}
}