WPF悬浮按钮
WPF实现窗体中的悬浮按钮，按钮可拖动，吸附停靠在窗体边缘。
创建一个用户控件，编写控件代码，
控件XAML代码：
后台CS代码：
public partial class FloatButton : Button
{
public event EventHandler ClickEvent;
private bool _move = false;
double _distance = 200;
double _distanceNew = 5;
private Point _lastPos;
private Point _newPos;
private Point _oldPos;
public FloatButton()
{
InitializeComponent();
}
private void btn_Loaded(object sender, RoutedEventArgs e)
{
if (this.Parent != null && this.Parent is FrameworkElement)
{
FrameworkElement parent = this.Parent as FrameworkElement;
double left = parent.ActualWidth - this.ActualWidth - this._distanceNew;
double top = parent.ActualHeight - this.ActualHeight - this._distanceNew;
this.Margin = new Thickness(left, top, 0, 0);
}
}
private void Border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
if (this.Parent != null && this.Parent is FrameworkElement)
{
FrameworkElement parent = this.Parent as FrameworkElement;
_move = true;
_lastPos = e.GetPosition(parent);
_oldPos = _lastPos;
parent.PreviewMouseMove += (s, ee) =>
{
if (_move)
{
Point pos = ee.GetPosition(parent);
double left = this.Margin.Left + pos.X - this._lastPos.X;
double top = this.Margin.Top + pos.Y - this._lastPos.Y;
this.Margin = new Thickness(left, top, 0, 0);
_lastPos = e.GetPosition(parent);
}
};
parent.PreviewMouseUp += (s, ee) =>
{
if (_move)
{
_move = false;
Point pos = ee.GetPosition(parent);
_newPos = pos;
double left = this.Margin.Left + pos.X - this._lastPos.X;
double top = this.Margin.Top + pos.Y - this._lastPos.Y;
double right = parent.ActualWidth - left - this.ActualWidth;
double bottom = parent.ActualHeight - top - this.ActualHeight;
if (left < _distance && top < _distance) //左上
{
left = this._distanceNew;
top = this._distanceNew;
}
else if (left < _distance && bottom < _distance) //左下
{
left = this._distanceNew;
top = parent.ActualHeight - this.ActualHeight - this._distanceNew;
}
else if (right < _distance && top < _distance) //右上
{
left = parent.ActualWidth - this.ActualWidth - this._distanceNew;
top = this._distanceNew;
}
else if (right < _distance && bottom < _distance) //右下
{
left = parent.ActualWidth - this.ActualWidth - this._distanceNew;
top = parent.ActualHeight - this.ActualHeight - this._distanceNew;
}
else if (left < _distance && top > _distance && bottom > _distance) //左
{
left = this._distanceNew;
top = this.Margin.Top;
}
else if (right < _distance && top > _distance && bottom > _distance) //右
{
left = parent.ActualWidth - this.ActualWidth - this._distanceNew;
top = this.Margin.Top;
}
else if (top < _distance && left > _distance && right > _distance) //上
{
left = this.Margin.Left;
top = this._distanceNew;
}
else if (bottom < _distance && left > _distance && right > _distance) //下
{
left = this.Margin.Left;
top = parent.ActualHeight - this.ActualHeight - this._distanceNew;
}
ThicknessAnimation marginAnimation = new ThicknessAnimation();
marginAnimation.From = this.Margin;
marginAnimation.To = new Thickness(left, top, 0, 0);
marginAnimation.Duration = TimeSpan.FromMilliseconds(200);
Storyboard story = new Storyboard();
story.FillBehavior = FillBehavior.Stop;
story.Children.Add(marginAnimation);
Storyboard.SetTargetName(marginAnimation, "btn");
Storyboard.SetTargetProperty(marginAnimation, new PropertyPath("(0)", Border.MarginProperty));
story.Begin(this);
this.Margin = new Thickness(left, top, 0, 0);
}
};
}
}
private void btn_Click(object sender, RoutedEventArgs e)
{
if (_newPos.Equals(_oldPos))
{
if (ClickEvent != null)
{
ClickEvent(sender, e);
}
}
}
}
}
调用控件代码：
效果图：
