在XAML代碼設計器中，添加canvas畫布與圓形幾何對象，利用VisualBrush筆刷來復制畫面內容到指定容器：
<Canvas x:Name="CvsGlass" Width="106" Height="106" HorizontalAlignment="Left" VerticalAlignment="Top" MouseWheel="CvsGlass_MouseWheel" MouseDown="CvsGlass_MouseDown" MouseUp="CvsGlass_MouseUp" MouseMove="CvsGlass_MouseMove" MouseLeave="CvsGlass_MouseLeave"> <Canvas.RenderTransform> <TransformGroup> <ScaleTransform/> </TransformGroup> </Canvas.RenderTransform> <Canvas Name="magnifierCanvas"> <Ellipse Width="106" Height="106" > <Ellipse.Fill> <LinearGradientBrush EndPoint="0.5,1" MappingMode="RelativeToBoundingBox" StartPoint="0.5,0"> <GradientStop Color="#FFD9D2D2" Offset="1"/> <GradientStop Color="White"/> <GradientStop Color="#FFDFDFDF" Offset="0.244"/> <GradientStop Color="#FF777777" Offset="0.592"/> </LinearGradientBrush> </Ellipse.Fill> </Ellipse> <Ellipse Width="100" Height="100" Canvas.Left="3" Canvas.Top="3" Fill="Black"/> <Ellipse Width="100" Height="100" Name="magnifierEllipse" Canvas.Left="3" Canvas.Top="3"> <Ellipse.Fill> <VisualBrush ViewboxUnits="Absolute" Viewbox="0,0,100,100" ViewportUnits="RelativeToBoundingBox" Viewport="0,0,1,1"/> </Ellipse.Fill> </Ellipse> <TextBlock x:Name="TxtGlassScale" Foreground="Yellow" Visibility="Hidden" FontSize="14" Margin="110,40,0,55" FontFamily="Microsoft YaHei"> <TextBlock.Effect> <DropShadowEffect/> </TextBlock.Effect> </TextBlock> </Canvas> </Canvas>
得到一個類似放大鏡的界面效果：
其中，TxtGlassScale是顯示放大鏡倍數的文字控件；
VisualBrush是內容筆刷，看效果：
其中需要注意的是，放大鏡應該是和Box平級，屬於Cell的子控件，這樣在圖像平鋪模式下則能兼容所有圖像范圍：
看效果：
參考代碼：
#region -----放大鏡-----/// <summary> /// 當前大小與vs設計器中的大小的比例 /// </summary> public double ActualScaleVal = 0; /// <summary> /// 放大比例 /// </summary> double glassScale = 2.0; /// <summary> /// 放大鏡視圖范圍寬度 /// </summary> double glassWidth = 0; /// <summary> /// 放大鏡視圖范圍高度 /// </summary> double glassHeight = 0; /// <summary> /// 顯示放大鏡 /// </summary> public void UseGlass() { if (CvsGlass.IsShow()) { CvsGlass.Hide(); return; } if (glassWidth == 0 || glassHeight == 0) { //計算放大鏡比例 100是放大鏡的viewbox的大小 glassWidth = 100 / glassScale; glassHeight = 100 / glassScale; } TxtGlassScale.Foreground = shapeManager.shapeMeasureColor; TxtGlassScale.FontSize = shapeManager.shapeMeasureFontSize; SetGlassViewBox(ActualWidth, ActualHeight, new Point(), true); CvsGlass.Show(); } /// <summary> /// 關閉放大鏡 /// </summary> public void CloseGlass() { CvsGlass.Hide(); } //滾輪控制放比例 private void CvsGlass_MouseWheel(object sender, MouseWheelEventArgs e) { if (e.Delta > 0) { glassScale -= 0.05; } else { glassScale += 0.05; } glassScale = glassScale < 0.1 ? 0.1 : glassScale; glassScale = glassScale > 5 ? 5 : glassScale; glassWidth = 100 / glassScale; glassHeight = 100 / glassScale; Point pos = e.MouseDevice.GetPosition(GridMain); SetGlassViewBox(pos.X, pos.Y, new Point(), false, false); TxtGlassScale.Text = ((glassScale * ActualScaleVal * 2) * 100).ToString("f1") + "%"; TxtGlassScale.Show(); } //是否按下放大鏡鼠標 bool isGlassDown = false; //記錄按下鼠標的位置 Point glassPoint = new Point(0, 0); //按下放大鏡 private void CvsGlass_MouseDown(object sender, MouseButtonEventArgs e) { glassPoint.X = e.GetPosition(CvsGlass).X; glassPoint.Y = e.GetPosition(CvsGlass).Y; isGlassDown = true; } //移動放大鏡 private void CvsGlass_MouseMove(object sender, MouseEventArgs e) { if (isGlassDown) { //相對於 GridLine 獲取鼠標的坐標 Point svMainPos = e.MouseDevice.GetPosition(ScrollCell); Point glassPos = e.MouseDevice.GetPosition(CvsGlass); SetGlassViewBox(glassPos.X, glassPos.Y, svMainPos, false); Mouse.Capture(CvsGlass); } } /// <summary> /// 設置放大內容 /// </summary> /// <param name="vbX">寬度參數</param> /// <param name="vbY">高度參數</param> /// <param name="svMainPos">相對於GridLine的坐標</param> /// <param name="isInit">是否是初始化</param> /// <param name="reLocation">是否重新定位坐標</param> private void SetGlassViewBox(double vbX, double vbY, Point svMainPos, bool isInit = false, bool reLocation = true) { Rect viewBox = GlassVB.Viewbox; double xoffset = viewBox.Width / 2.0; double yoffset = viewBox.Height / 2.0; if (isInit) { viewBox.X = (vbX - xoffset) / 2; viewBox.Y = (vbY - yoffset) / 2; CvsGlass.Margin = new Thickness((vbX - 106) / 2, (vbY - 106) / 2, (vbX - 106) / 2, (vbY - 106) / 2); } else { if (reLocation) { viewBox.X = svMainPos.X - xoffset - (vbX - 106 / 2); viewBox.Y = svMainPos.Y - yoffset - (vbY - 106 / 2); CvsGlass.Margin = new Thickness( CvsGlass.Margin.Left + vbX - glassPoint.X, CvsGlass.Margin.Top + vbY - glassPoint.Y, CvsGlass.Margin.Right - vbX + glassPoint.X, CvsGlass.Margin.Bottom - vbY + glassPoint.Y); } } viewBox.Width = glassWidth; viewBox.Height = glassHeight; GlassVB.Viewbox = viewBox; TxtGlassScale.Hide(); } private void CvsGlass_MouseLeave(object sender, MouseEventArgs e) { isGlassDown = false; } private void CvsGlass_MouseUp(object sender, MouseButtonEventArgs e) { isGlassDown = false; Mouse.Capture(null); } /// <summary> /// 重新設置放大鏡大小和位置 /// </summary> public void ReSetGlass() { if (BoxList.Count == 0) { return; } //*2是因為放大鏡在vs設計器中顯小 放大兩倍 BoxList[0].SetScaleTrans(CvsGlass, ActualScaleVal * 2, ActualScaleVal * 2, false); if (CvsGlass.Margin.Left >= ActualWidth || CvsGlass.Margin.Top >= ActualHeight) { CvsGlass.Margin = new Thickness((ActualWidth - 106) / 2, (ActualHeight - 106) / 2, (ActualWidth - 106) / 2, (ActualHeight - 106) / 2); } } #endregion