WPF之行为
标签：code parent override rgs 位置 over cte div ase
Behavior的运用扩展了”交互“功能，以下记录示例：
在的项目中添加两个引用：
Microsoft.Expression.Interactions.dll
System.Windows.Interactivity.dll
Canvas>
Rectangle Height="40" Width="80" Canvas.Left="100" Canvas.Top="50" Fill="Aqua">
i:Interaction.Behaviors>
local:DragInCanvsBehavior/>
i:Interaction.Behaviors>
Rectangle>
Ellipse Height="40" Width="80" Fill="AntiqueWhite"/>
Canvas>
主要是实现OnAttached()和OnDetaching()方法，在OnAttached()方法中关联事件处理程序，在OnDetaching()中移除事件处理程序。
public class DragInCanvsBehavior : Behavior
{
private Canvas m_Canvas;
private bool m_IsDraging;
private Point m_PositionOffset;
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.MouseLeftButtonDown += AssociatedObject_MouseLeftButtonDown;
AssociatedObject.MouseMove += AssociatedObject_MouseMove;
AssociatedObject.MouseLeftButtonUp += AssociatedObject_MouseLeftButtonUp;
}
void AssociatedObject_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
{
if (!m_IsDraging)
return;
Point mouseposition = e.GetPosition(m_Canvas);//得到鼠标相对于Canvas对象的位置
AssociatedObject.SetValue(Canvas.LeftProperty, mouseposition.X - m_PositionOffset.X);//获得需要移动的相对距离
AssociatedObject.SetValue(Canvas.TopProperty, mouseposition.Y - m_PositionOffset.Y);
}
void AssociatedObject_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
if (!m_IsDraging)
return;
m_IsDraging = false;
AssociatedObject.ReleaseMouseCapture();//释放鼠标的捕获
}
void AssociatedObject_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
if (m_Canvas == null)
m_Canvas = (Canvas)VisualTreeHelper.GetParent(AssociatedObject);//捕捉到附加对象的父对象
m_IsDraging = true;
m_PositionOffset = e.GetPosition(AssociatedObject);//得到鼠标相对于附加对象的位置
AssociatedObject.CaptureMouse();//鼠标捕获到元素
}
protected override void OnDetaching()
{
base.OnDetaching();
AssociatedObject.MouseLeftButtonDown -= AssociatedObject_MouseLeftButtonDown;
AssociatedObject.MouseMove -= AssociatedObject_MouseMove;
AssociatedObject.MouseLeftButtonUp -= AssociatedObject_MouseLeftButtonUp;
}
}
WPF之行为
标签：code parent override rgs 位置 over cte div ase
原文地址：https://www.cnblogs.com/qcst123/p/12071510.html
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WPF之行为
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