Question

我需要在滑块的拇指被拖动到新值时触发事件，或者使用对齐点击到新值。我只希望在使用鼠标这两种方式更改值时发生此事件，因此ValueChanged事件将无效。

Answer 1

你可以尝试这个小技巧

首先，您需要将UpdateSourceTrigger设置为Explicit

<Slider Minimum="0"
        Thumb.DragStarted="Slider_DragStarted"
        Thumb.DragCompleted="Slider_DragCompleted"
        Maximum="{Binding YourMaxBinding, Mode=OneWay}"
        Value="{Binding CurrentPosition, Mode=TwoWay, UpdateSourceTrigger=Explicit}" />

背后的代码

private void Slider_DragStarted(object sender, System.Windows.Controls.Primitives.DragStartedEventArgs e) {
    // try to prevent updating slider position from your view model
    yourViewModel.DontUpdateSliderPosition = true;
}

private void Slider_DragCompleted(object sender, System.Windows.Controls.Primitives.DragCompletedEventArgs e) {
    BindingExpression be = ((Slider)sender).GetBindingExpression(RangeBase.ValueProperty);
    if (be != null) {
      be.UpdateSource();
    }
    yourViewModel.DontUpdateSliderPosition = false;
}

您的视图模型中的代码

private bool _dontUpdateSliderPosition;
public bool DontUpdateSliderPosition {
    get {
        return _dontUpdateSliderPosition;
    }
    set {
        if (Equals(value, _dontUpdateSliderPosition)) {
            return;
        }
        _dontUpdateSliderPosition = value;
        yourPropertyChangedFunc("DontUpdateSliderPosition");
    }
}

private int _currentPosition;
public int CurrentPosition {
    get {
        return _currentPosition;
    }
    set {
        if (Equals(value, _currentPosition)) {
            return;
        }
        _currentPosition = value;
        yourPropertyChangedFunc("CurrentPosition");
    }
}

private CodeBehindFuncToChangeTheSliderPosition(){
    if (!DontUpdateSliderPosition) {
        CurrentPosition = theNewPosition;
    }
}

希望这会有所帮助

滑块 - 捕捉指向并拖动事件

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