C# wpf Grid中实现控件拖动调整大小的示例代码

2022-12-01 13:13 开发作者： CodeOfCC

前言

在《C# wpf Canvas中实现控件动态调整大小》中我们实现了Canvas中的控件动态调整大小，由于Grid也是可层叠布局，在Grid中也是可以实现动态调整大小的。

一、功能说明

8个点方放置在控件的8个方位上，通过拖动这些点对控件进行拉伸或缩小，示意图如下：

C# wpf Grid中实现控件拖动调整大小的示例代码

二、如何实现？

1.继承Adorner

通过装饰器的方式添加8个点在控件上，这样既可以不影响控件布局，又可以自由摆放8点控件。通过重写方法，给装饰添加控件。必www.devze.com要的重写的方法如下面示例所示：

public class GridAdorner : Adorner
{
  //获取装饰器的元素个数
  protected override Visual GetVisualChild(int index);
  //指定装饰器子元素个数
  protected override int VisualChildrenCount{get;}
  //布局，添加的子元素需要手动布局。
  protected override Size ArrangeOverride(Size finalSize);      
}

2.使用Thumb

因为Thumb实现拖动比较容易，有相关事件获取拖动距离。在装饰器中定义8个Thumb，对应8个方位点。

示例代码如下：

//4条边
Thumb _leftThumb, _topThumb, _rightThumb, _bottomThumb;
//4个角
Thumb _lefTopThumb, _rightTopThumb, _rightBottomThumb, _leftbottomThumb;

初始化

 public GridAdorner(UIElement adornedElement) : base(adornedElement)
 {
     //初始化thumb
     _leftThumb = new Thumb();
     _leftThumb.HorizontalAlignment = HorizontalAlignment.Left;
     _leftThumb.VerticalAlignment = VerticalAlignment.Center;
     _leftThumb.Cursor = Cursors.SizeWE;
     //其他略...
}

3.实现拖动逻辑

在Thumb的DragDelta事件可以获取拖动距离，根据八个方位的不同计算并修改控件的大小。

private void Thumb_DragDelta(object sender, DragDeltaEventArgs e)
{
//1.右侧点HorizontalChange加宽，右边距减HorizontalChange
//2.左侧点HorizontalChange减宽，左边距加HorizontalChange
//3.下侧点VerticalChange加高，下边距减VerticalChange
//4.上侧点VerticalChange减高，上边距加VerticalChange
}

三、完整代码

代码如下：

 public class GridAdorner : Adorner
    {
        //4条边
        Thumb _leftThumb, _topThumb, _rightThumb, _bottomThumb;
        //4个角
        Thumb _lefTopThumb, _rightTopThumb, _rightBottomThumb, _leftbottomThumb;
        //布局容器，如果不使用布局容器，则需要给上述8个控件布局，实现和Grid布局定位是一样的，会比较繁琐且意义不大。
        Grid _grid;
        UIElement _adornedElement;
        public GridAdorner(UIElement adornedElement) : base(adornedElement)
        {
            _adornedElement = adornedElement;
            //初始化thumb
            _leftThumb = new Thumb();
            _leftThumb.HorizontalAlignment = HorizontalAlignment.Left;
            _leftThumb.VerticalAlignment = VerticalAlignment.Center;
            _leftThumb.Cursor = Cursors.SizeWE;
            _topThumb = new Thumb();
            _topThumb.HorizontalAlignment = HorizontalAlignment.Center;
            _topThumb.VerticalAlignment = VerticalAlignment.Top;
            _topThumb.Cursor = Cursors.SizeNS;
            _rightThumb = new Thumb();
            _rightThumb.HorizontalAlignment = HorizontalAlignment.Right;
            _rightThumb.VerticalAlignment = VerticalAlignment.Center;
            _rightThumb.Cursor = Cursors.SizeWE;
            _bottomThumb = new Thumb();
            _bottomThumb.HorizontalAlignment = HorizontalAlignment.Center;
            _bottomThumb.VerticalAlignment = VerticalAlignment.Bottom;
            _bottomThumb.Cursor = Cursors.SizeNS;
            _lefTopThumb = new Thumb();
            _lefTopThumb.HorizontalAlignment = HorizontalAlignment.Left;
            _lefTopThumb.VerticalAlignment = VerticalAlignment.Top;
            _lefTopThumb.Cursor = Cursors.SizeNhttp://www.devze.comWSE;
            _rightTopThumb = new Thumb();
            _rightTopThumb.HorizontalAlignment = HorizontalAlignment.Right;
            _rightTopThumb.VerticalAlignment = VerticalAlignment.Top;
            _rightTopThumb.Cursor = Cursors.SizeNESW;
            _rightBottomThumb = new Thumb();
            _rightBottomThumb.HorizontalAlignment = HorizontalAlignment.Right;
            _rightBottomThumb.VerticalAlignment = VerticalAlignment.Bottom;
            _rightBottomThumb.Cursor = Cursors.SizeNWSE;
            _leftbottomThumb = new Thumb();
            _leftbottomThumb.HorizontalAlignment = HorizontalAlignment.Left;
            _leftbottomThumb.VerticalAlignment = VerticalAlignment.Bottom;
            _leftbottomThumb.Cursor = Cursors.SizeNESW;
            _grid = new Grid();
            _grid.Children.Add(_leftThumb);
            _grid.Children.Add(_topThumb);
            _grid.Children.Add(_rightThumb);
            _grid.Children.Add(_bottomThumb);
            _grid.Children.Add(_lefTopThumb);
            _grid.Children.Add(_rightTopThumb);
            _grid.Children.Add(_rightBottomThumb);
            _grid.Children.Add(_leftbottomThumb);
            AddVisualChild(_grid);
            foreach (Thumb thumb in _grid.Children)
            {
                thumb.Width = 16;
                thumb.Height = 16;
                thumb.Background = Brushes.Green;
                thumb.Template = new ControlTemplate(typeof(Thumb))
                {
                    VisualTree = GetFactory(new SolidColorBrush(Colors.White))
                };
                thumb.DragDelta += Thumb_DragDelta;
            }
        }
        protected override Visual GetVisualChild(int index)
        {
            return _grid;
        }
        protected override int VisualChildrenCount
        {
            get
            {
                return 1;
            }
        }
        protected override Size ArrangeOverride(Size finalSize)
        {
            //直接给grid布局，grid内部的thumb会自动布局。
            _gr开发者_JAV培训id.Arrange(new Rect(new Point(-_leftThumb.Width / 2, -_leftThumb.Height / 2), new Size(finalSize.Width + _leftThumb.Width, finalSize.Height + _leftThumb.Height)));
            return finalSize;
        }
        //拖动逻辑
        private void Thumb_DragDelta(object sender, DragDeltaEventArgs e)
        {
            var c = _adornedElement as FrameworkElement;
            var thumb = sender as FrameworkElement;
            double left, top, right, bottom, width, height;
            if (thumb.HorizontalAlignment == HorizontalAlignment.Left)
            {
                right = c.Margin.Right;
                left = c.Margin.Left + e.HorizontalChange;
                width =(double.IsNaN(c.Width)?c.Actuawww.devze.comlWidth:c.Width)- e.HorizontalChange;
            }
            else
            {
                left = c.Margin.Left;
                right = c.Margin.Right - e.HorizontalChange;
                width = (double.IsNaN(c.Width) ? c.ActualWidth : c.Width )+ e.HorizontalChange;
            }

            if (thumb.VerticalAlignment == VerticalAlignment.Top)
            {
                bottom = c.Margin.Bottom;
                top = c.Margin.Top + e.VerticalChange;
                height = (double.IsNaN(c.Height) ? c.ActualHeight : c.Height) - e.VerticalChange;

            }
            else
            {
                top = c.Margin.Top;
                bottom = c.Margin.Bottom - e.VerticalChange;
                height = (double.IsNaN(c.Height) ? c.ActualHeight : c.Height )+ e.VerticalChange;
            }
            if (thumb.HorizontalAlignment != HorizontalAlignment.Center)
            {
                if (width >= 0)
                {
                    c.Margin = new Thickness(left, c.Margin.Top, right, c.Margin.Bottom);
                    c.Width = width;
                }
            }
            if (thumb.VerticalAlignment != VerticalAlignment.Center)
            {
                if (height >= 0)
                {
                    c.Margin = new Thickness(c.Margin.Left, top, c.Margin.Right, bottom);
                    编程客栈c.Height = height;
                }
            }
        }
        //thumb的样式
        FrameworkElementFactory GetFactory(Brush back)
        {
            var fef = new FrameworkElementFactory(typeof(Ellipse));
            fef.SetValue(Ellipse.FillProperty, back);
            fef.SetValue(Ellipse.StrokeProperty, new SolidColorBrush((Color)ColorConverter.ConvertFromString("#999999")));
            fef.SetValue(Ellipse.StrokeThicknessProperty, (double)2);
            return fef;
        }
    }

四、使用示例

示例代码如下：

XML

<Grid>
    <Border  x:Name="border"  Width="200" Height="200"  Background="Gray" ></Border>
</Grid>

在窗口或控件的Loaded事件中添加装饰器：

private void window_Loaded(object sender, RoutedEventArgs e)
{
    var layer = AdornerLayer.GetAdornerLayer(border);
    layer.Add(new GridAdorner(border));
}

效果预览：

C# wpf Grid中实现控件拖动调整大小的示例代码

总结

以上就是今天要讲的内容，本文讲述了Grid中控件缩放的方法与实现，与Canvas的实现大部分是相同的，唯一的区别就是设置Margin，总得来说还是比较容易实现的，最终呈现的效果也是比较不错的。

到此这篇关于C# wpf Grid中实现控件拖动调整大小的示例代码的文章就介绍到这了,更多相关C# wpf Grid拖动调整大小内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！

继续阅读：C#wpfGrid拖动 C#wpfGrid拖动调整大小

C# wpf Grid中实现控件拖动调整大小的示例代码

目录

前言

一、功能说明

二、如何实现？

1.继承Adorner

2.使用Thumb

3.实现拖动逻辑

三、完整代码

四、使用示例

总结

更多精彩内容

精彩评论

最新开发

如何实现Python编写的图形界面可以自由拖动

mysql字符集引起的java.sql.SQLException:Incorrect string value:问题

解决Feign异步调用丢失上下文问题

python模拟重载初始化函数的方法详解

SQL注入攻击及其在SpringBoot中使用MyBatisPlus的防范策略的方法

开发排行榜

springboot后端存储富文本内容的思路与步骤(含图片内容)

PyCharm运行python测试,报错“没有发现测试”/“空套件”的解决

return base64.b64encode(b).decode(

基于C语言实现钻石棋游戏的示例代码

Sublime Text 3解决中文乱码问题（实测可用）