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自定义类设置程序未更新

wpf c#

eye_am_groot · 技术社区 · 6 年前

我有课, KeyCombos 包含 Modifier Keys 和 Keys

private ModifierKeys _modifierKeys;
private Key _key;

public ModifierKeys ModifierKeys
{
    get { return _modifierKeys; }
    set
    {
        if (_modifierKeys == value)
            return;

        _modifierKeys = value;
        RaisePropertyChanged(nameof(ModifierKeys));
    }
}

public Key Key
{
    get { return _key; }
    set
    {
        if (_key == value)
            return;

        _key = value;
        RaisePropertyChanged(nameof(Key));
    }
}

public KeyCombo(ModifierKeys modifierKeys, Key key)
{
    Key = key;
    ModifierKeys = modifierKeys;
}

哪里 RaisePropertyChanged INotifyPropertyChanged .

在我的 ViewModel ,我有绑定到各种组合键的属性,例如:

private KeyCombo _firstKeyCombo;
public KeyCombo FirstKeyCombo
{
    get { return _firstKeyCombo; }
    set
    {
        if (_firstKeyCombo == value)
            return;

        _firstKeyCombo = value;
        // Validation method called here
        RaisePropertyChanged(nameof(FirstKeyCombo));
    }
}

每一部分 KeyCombo 设置在 视图模型 ,即:

FirstKeyCombo = new KeyCombo(ModifierKeys.Alt, Key.T);

public IEnumerable<Key> Keys => _availableKeys;
ObservableCollection<Key> _availableKey; // set to all available keys
public IEnumerable<ModifierKeys> Modifiers => _modifierKeys;
ObservableCollection<ModifierKeys> _modifierKeys;  // set to all modifier keys

然后被捆绑在 View 到 ComboBoxs :

<StackPanel Orientation="Horizontal" Grid.Row="13" Grid.Column="2">
    <ComboBox ItemsSource="Keys" 
              SelectedItem="{Binding FirstKeyCombo.Key, 
                       Mode=TwoWay, 
                       UpdateSourceTrigger=PropertyChanged}"/>
    <ComboBox ItemsSource="Modifiers" 
              SelectedItem="{Binding FirstKeyCombo.ModifierKey, 
                       Mode=TwoWay, 
                       UpdateSourceTrigger=PropertyChanged}"/>
</StackPanel>

这个很好,合适的 Key 和 ModifierKeys 正确显示。我需要更新 FirstKeyCombo 当 钥匙 或 ModiferKeys 更改(验证结束) 的 按键组合 InotifyProperty已更改 修改键 钥匙 )通过 Combobox 第一键组合

1 回复 | 直到 6 年前

Andreas 6 年前

因此,在创建FirstKeyCombo之后,添加PropertyChangedEventhandler

FirstKeyCombo.PropertyChanged += OnFirstKeyComboPropertyChanged;

应该是这样的:

private void OnFirstKeyComboPropertyChanged(object sender, PropertyChangedEventArgs e)
{
  //remove the handler
  FirstKeyCombo.PropertyChanged -= OnFirstKeyComboPropertyChanged;
  //create new object because of referential equlity check in WPF
  FirstKeyCombo = new KeyCombo(FirstKeyCombo.ModifierKeys, FirstKeyCombo.Key);
  //add the handler to the new object
  FirstKeyCombo.PropertyChanged += OnFirstKeyComboPropertyChanged;
}

RaisePropertyChanged(nameof(FirstKeyCombo));

至于评论,这就是反思的方式。KeyCombo.名称必须是属性的名称。

private void OnFirstKeyComboPropertyChanged(object sender, PropertyChangedEventArgs e)
{
  KeyCombo combo = sender as KeyCombo;
  //remove the handler
  combo.PropertyChanged -= OnFirstKeyComboPropertyChanged;
  //create new object because of referential equlity check in WPF
  combo = new KeyCombo(combo.ModifierKeys, combo.Key, combo.Name);
  //add the handler to the new object
  combo.PropertyChanged += OnFirstKeyComboPropertyChanged;
  //Get the ViewModel-Type
  Type t = ViewModel.GetType();
  //Get the property with the name
  PropertyInfo pi = t.GetProperty(combo.Name);
  //set the value of the property
  pi.SetValue(ViewModel,combo);
}

或者用字典。也KeyCombo.名称必须是属性的名称。

private void OnFirstKeyComboPropertyChanged(object sender, PropertyChangedEventArgs e)
{
  KeyCombo combo = sender as KeyCombo;
  //remove the handler
  combo.PropertyChanged -= OnFirstKeyComboPropertyChanged;
  //create new object because of referential equlity check in WPF
  combo = new KeyCombo(combo.ModifierKeys, combo.Key, combo.Name);
  //add the handler to the new object
  combo.PropertyChanged += OnFirstKeyComboPropertyChanged;
  dictionaryWithAllCombos[combo.Name] = combo;
  RaisePropertyChanged(combo.Name);
}

在ViewModel中

public FirstKeyCombo FirstKeyCombo
{
  get { return dictionary["FirstKeyCombo"]; }
  set 
  { 
    dictionaryWithAllCombos["FirstKeyCombo"] = value; 
    RaisePropertyChanged(nameof(FirstKeyCombo));
  }
}