标签：logical scan enc canvas clr 鼠标 splay from 文件
1,该项目分析:
2,wpf布局:
<Window x:Class="Drawing.VisualLayer" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="VisualLayer" Height="350.4" Width="496.8" xmlns:local="clr-namespace:Drawing" > <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"></ColumnDefinition> <ColumnDefinition></ColumnDefinition> </Grid.ColumnDefinitions> <ToolBarTray Orientation="Vertical"> <ToolBar> <RadioButton Margin="0,3" Name="cmdSelectMove"> <StackPanel> <Image Source="pointer.png" Width="35" Height="35"></Image> <TextBlock>Select/Move</TextBlock> </StackPanel> </RadioButton> <RadioButton Margin="0,3" IsChecked="True" Name="cmdAdd"> <StackPanel> <Rectangle Width="30" Height="30" Stroke="SteelBlue" StrokeThickness="3" Fill="AliceBlue"></Rectangle> <TextBlock>Add Square</TextBlock> </StackPanel> </RadioButton> <RadioButton Margin="0,3" Name="cmdDelete"> <StackPanel> <Path Stroke="SteelBlue" StrokeThickness="4" StrokeEndLineCap="Round" StrokeStartLineCap="Round" Fill="Red" HorizontalAlignment="Center"> <Path.Data> <GeometryGroup> <PathGeometry> <PathFigure StartPoint="0,0"> <LineSegment Point="18,18"></LineSegment> </PathFigure> <PathFigure StartPoint="0,18"> <LineSegment Point="18,0"></LineSegment> </PathFigure> </PathGeometry> </GeometryGroup> </Path.Data> </Path> <TextBlock>Delete Square</TextBlock> </StackPanel> </RadioButton> <RadioButton Margin="0,3" Name="cmdSelectMultiple"> <StackPanel> <Image Source="pointer.png" Width="35" Height="35"></Image> <TextBlock>Select Multiple</TextBlock> </StackPanel> </RadioButton> </ToolBar> </ToolBarTray> <Border Grid.Column="1" Margin="3" BorderBrush="SteelBlue" BorderThickness="1"> <local:DrawingCanvas x:Name="drawingSurface" Background="White" ClipToBounds="True" MouseLeftButtonDown="drawingSurface_MouseLeftButtonDown" MouseLeftButtonUp="drawingSurface_MouseLeftButtonUp" MouseMove="drawingSurface_MouseMove"> </local:DrawingCanvas> </Border> </Grid> </Window>
创建了左右两栏,1栏是工具栏,1栏是画图栏.
右侧创建画图对象.
1,添加图形对象的逻辑:(必须设置背景颜色)
1,生成VisualDrawing对象.然后添加到Canvas对象之中
private List<Visual> visuals = new List<Visual>(); protected override Visual GetVisualChild(int index) { return visuals[index]; } protected override int VisualChildrenCount { get { return visuals.Count; } } public void AddVisual(Visual visual) { visuals.Add(visual); base.AddVisualChild(visual); base.AddLogicalChild(visual); } public void DeleteVisual(Visual visual) { visuals.Remove(visual); base.RemoveVisualChild(visual); base.RemoveLogicalChild(visual); }
2 获取VisualDrawing对象.并且删除
public DrawingVisual GetVisual(Point point) { HitTestResult hitResult = VisualTreeHelper.HitTest(this, point); return hitResult.VisualHit as DrawingVisual; } private List<DrawingVisual> hits = new List<DrawingVisual>(); public List<DrawingVisual> GetVisuals(Geometry region) { hits.Clear(); GeometryHitTestParameters parameters = new GeometryHitTestParameters(region); HitTestResultCallback callback = new HitTestResultCallback(this.HitTestCallback); VisualTreeHelper.HitTest(this, null, callback, parameters); return hits; } private HitTestResultBehavior HitTestCallback(HitTestResult result) { GeometryHitTestResult geometryResult = (GeometryHitTestResult)result; DrawingVisual visual = result.VisualHit as DrawingVisual; if (visual != null && geometryResult.IntersectionDetail == IntersectionDetail.FullyInside) { hits.Add(visual); } return HitTestResultBehavior.Continue; }
命中测试:
删除操作:
public void DeleteVisual(Visual visual) { visuals.Remove(visual); base.RemoveVisualChild(visual); base.RemoveLogicalChild(visual); }
3,获得当前坐标的当前位置值:
当获取Visual的ContentBounds的时候,其实际上包含了一半的线宽:
Point curPos = new Point(visual.ContentBounds.TopLeft.X + pen.Thickness / 2, visual.ContentBounds.TopLeft.Y + pen.Thickness / 2);4 ,如何绘制虚线框:
首先根据选择,在Down的时候,开始加入一个Visual对象
else if (cmdSelectMultiple.IsChecked == true) { selectionSquare = new DrawingVisual(); drawingSurface.AddVisual(selectionSquare); selectionSquareTopLeft = pointClicked; isMultiSelecting = true; // Make sure we get the MouseLeftButtonUp event even if the user // moves off the Canvas. Otherwise, two selection squares could be drawn at once. drawingSurface.CaptureMouse(); }
,然后在移动的过程中绘制该对象
if (isDragging) { Point pointDragged = e.GetPosition(drawingSurface) + clickOffset; DrawSquare(selectedVisual, pointDragged, true); } else if (isMultiSelecting) { Point pointDragged = e.GetPosition(drawingSurface); DrawSelectionSquare(selectionSquareTopLeft, pointDragged); }
//
另外理解下OffSet 的含义:
首先 定义了 OffSetPoint=元素左上角1-鼠标点击1;
定义
元素左上角2=鼠标点击2+OffSetPoint;
注意:OffSetPoint是相对于鼠标点击的位置,所以,可以所示 元素对应鼠标的偏移值,所以,元素位置2,可以用 鼠标位置2+相对值来求出来.
可以定义表达式 : 元素左上角2-元素左上角1=鼠标点击2-鼠标点击1;
二:效果
三:位图:
格局格式决定每个像素点的字节数:
其中 Stride是每行占用字节数的4的取整. 可以使用 (Nums+3)/4*4来获取.
32位RGB：假设X、Y为位图中像素的坐标，则其在内存中的地址为scan0+Ystride+X4。此时指针指向蓝色，其后分别是绿色、红色，alpha分量。
24位RGB：scan0+Ystride+X3。此时指针指向蓝色，其后分别是绿色和红色。
8位索引：scan0+Ystride+X。当前指针指向图像的调色盘。
4位索引：scan0+Ystride+（X/2）。当前指针所指的字节包括两个像素，通过高位和低位索引16色调色盘，其中高位表示左边的像素，低位表示右边的像素。
1位索引：scan0+Y*stride+X/8。当前指针所指的字节中的每一位都表示一个像素的索引颜色，调色盘为两色，最左边的像素为8，最右边的像素为0。
使用LockBits方法进行将Bitmap 转换为writebleBitmap的方式
private WriteableBitmap ConvertFromBitmap(System.Drawing.Bitmap bitmap) { var tt = bitmap; var dt = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly,bitmap.PixelFormat); Byte* p = (Byte *)dt.Scan0; WriteableBitmap bitmap1 = new WriteableBitmap(bitmap.Width, bitmap.Height, 96, 96, PixelFormats.Bgra32, null); Int32Rect rect = new Int32Rect(0, 0, bitmap.Width, bitmap.Height); Byte[] pixels = new Byte[bitmap.Width * bitmap.Height * 4]; for(var i=0;i<pixels.Length;i++) { pixels[i] = *(p + i); } bitmap.UnlockBits(dt); bitmap1.WritePixels(rect, pixels, dt.Stride, 0); pixels = null; return bitmap1; }
本质上操作位图就是操作一个bytes数组.只要注意颜色.是按照(B,G,R,A)格式来就可以了.
四 自定义效果以及实现 https://blog.csdn.net/WPwalter/article/details/90575912
1,下载并安装软件https://gitee.com/mao_qin_bin/download/tree/master/Shazzam
2,认识该编辑器:
.fx 是 着色语言生成文件.
标签：logical scan enc canvas clr 鼠标 splay from 文件
原文地址：https://www.cnblogs.com/frogkiller/p/13151791.html
