原理介绍

README.md

@@ -6,3 +6,58 @@ CorelDRAW VBA 插件 简易的长宽高盒子插件和源码和步骤原理
 
 https://www.bilibili.com/video/BV1MF411f7qu/
 
+### 前两天在本论坛看到网友，问怎么绘制如下图简单的封套盒子。所以有了思路，就动手写了代码
+
+![](https://lyvba.com/wp-content/uploads/2023/08/box1.png)
+
+```bas
+Public Function Simple_box_one()
+  ActiveDocument.Unit = cdrMillimeter
+  l = 100: w = 50: h = 70: b = 15
+  boxL = 2 * l + 2 * w + b
+  boxH = h
+  l1x = w
+  l2x = w + l
+  l3x = 2 * w + l
+  l4x = 2 * (w + l)
+  
+  Set Rect = ActiveLayer.CreateRectangle(0, 0, boxL, boxH)
+  Set sl1 = DrawLine(l1x, 0, l1x, h)
+  Set sl2 = DrawLine(l2x, 0, l2x, h)
+  Set sl3 = DrawLine(l3x, 0, l3x, h)
+  Set sl4 = DrawLine(l4x, 0, l4x, h)
+End Function
+```
+
+### 代码中的公式，不用初中知识应该就可以理解的。就是计算矩形多大，绘制4条线，把线移动到正确的位置
+
+![](https://lyvba.com/wp-content/uploads/2023/08/box2.png)
+```
+Public Function Simple_box_two()
+  ActiveDocument.Unit = cdrMillimeter
+  l = 100: w = 50: h = 70: b = 15
+  boxL = 2 * l + 2 * w + b: boxH = h
+  l1x = w: l2x = w + l: l3x = 2 * w + l: l4x = 2 * (w + l)
+  
+  Set mainRect = ActiveLayer.CreateRectangle(0, 0, boxL, boxH)
+  
+  Set topRect = ActiveLayer.CreateRectangle(0, 0, l, w)
+  topRect.Move l1x, h
+  Set bottomRect = ActiveLayer.CreateRectangle(0, 0, l, w)
+  bottomRect.Move l3x, -w
+  
+  Set sl1 = DrawLine(l1x, 0, l1x, h)
+  Set sl2 = DrawLine(l2x, 0, l2x, h)
+  Set sl3 = DrawLine(l3x, 0, l3x, h)
+  Set sl4 = DrawLine(l4x, 0, l4x, h)
+End Function
+```
+
+### 绘制线条的代码写成函数调用，可以设置颜色或者粗细
+```
+'// 画一条线，设置轮廓色 M100
+Private Function DrawLine(X1, Y1, X2, Y2) As Shape
+  Set DrawLine = ActiveLayer.CreateLineSegment(X1, Y1, X2, Y2)
+  DrawLine.Outline.SetProperties Color:=CreateCMYKColor(0, 100, 0, 0)
+End Function
+```