计算机地图制图原理与方法实验报告.doc

Windows绘图
一、实验目的：
了解windows绘图的一般过程；
增强对课本基本原理的理解；
以vc++为主，学习高级语言图形编程技术
二、实验过程：
该实验采用visual basic作为编程语言，首先根据VB的特性制定一下的整体思路：

主要实现曲线、圆、点、直线等图形的绘制，利用鼠标的mousemove、mousedown、mouseup三个事件，分情况进行处理，以此实现对不同选项的响应。
界面如下：

主要代码：

Dim ljs As Integer '必须定义为全局变量
Dim drawstate As Boolean '定义画笔状态，左键按下为有效
Dim prex As Single '坐标初始值，在左键按下后记录
Dim prey As Single '坐标初始值，在左键按下后记录

Private Sub Combo1_Change()
Picture1.DrawWidth = Val(Combo1)
End Sub

Private Sub Command1_Click()
ljs = 1
Label4.Caption = "温馨提示：请拖动鼠标左键绘制曲线，右键单击取消该操作"
'line
End Sub

Private Sub Command2_Click()
ljs = 2
Label4.Caption = "温馨提示：单击鼠标左键确定圆心，拖动直至松开鼠标左键，右键单击取消该操作"
'circle
End Sub

Private Sub Command3_Click()
ljs = 3
Label4.Caption = "温馨提示，单击鼠标左键即可"
'point
End Sub

Private Sub Command4_Click()
ljs = 4
'line
Label4.Caption = "温馨提示：按住鼠标左键，拖动直至松开鼠标左键"
End Sub

Private Sub Command5_Click()
Form2.Show
Form1.Visible = True
End Sub

Private Sub Command6_Click()
ljs = 6
Label4.Caption = "注记，输入文字后，按鼠标左键确定位置"
Char = InputBox("请输入注记文字", "注记", "surveying")
End Sub

Private Sub Form_Load()
Text1 = ""
Text2 = ""
Label4.Caption = "欢迎使用本绘图程序，请根据提示进行操作"
End Sub

'以下为三个鼠标事件，针对前面的选项依次处理
Private Sub Picture1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
'分选项进行讨论
If ljs = 1 Then
If Button = 1 Then
Picture1.DrawWidth = 1
drawstate = True '此处做一个标记
prex = X
prey = Y
End If
If Button = 2 Then
ljs = 0 ' 鼠标右键终止当前画笔
End If
End If

If ljs = 2 Then
If Button = 1 Then
drawstate = True '此处做一个标记
prex = X
prey = Y
End If
If Button = 2 Then
ljs = 0 ' 鼠标右键终止当前画笔
End If

End If

If ljs = 3 Then
If Button = 1 Then
Picture1.DrawWidth = 5 'drawwidth是全局属性
Picture1.PSet (X, Y)
End If
If Button = 2 Then
ljs = 0
End If
End If

If ljs = 4 Then
If Button = 1 Then
prex = X
prey = Y
End If
End If
End Sub

Private Sub Picture1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Text1 = X
Text2 = Y
'显示当前坐标
If ljs = 1 Then
If drawstate = True Then
Picture1.DrawWidth = 1
Picture1.Line (prex, prey)-(X, Y) '指定在picture1中操作
prex = X
prey = Y
End If
End If
：

End Sub

Private Sub Picture1_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
If ljs = 1 Then
If Button = 1 Then
drawstate = False
End If
End If

If ljs = 2 Then
Picture1.DrawWidth = 1
Dim r As Single
If Button = 1 Then
drawstate = False
End If
r = Sqr((X - prex) * (X - prex) + (Y - prey) * (Y - prey))
Picture1.Circle (prex, prey), r
End If

If ljs = 4 Then
Picture1.DrawWidth = 1
If Button = 1 Then
Picture1.Line (prex, prey)-(X, Y)
End If
End If
End Sub
签名代码
Private Sub Command1_Click()
Form2.Show
Form3.Visible = False
End Sub

Private Sub Command2_Click()
Dim i As Integer
Picture1.Scale (0, 0)-(31, 31)
For i = 1 To 30
Picture1.Line (i, 0)-(i, 41)
Picture1.Line (0, i)-(31, i)
Next i
Command3.Enabled = True
End Sub

Private Sub Command3_Click()
Dim i As Integer
Dim j As Integer
Picture1.DrawWidth = 1
For i = 1 To 30
For j = 1 To 30
Picture1.Circle (i, j), 0.2 '必须指明对picture进行操作，默认是form
Next j
Next i
Command4.Enabled = True
End Sub

Private Sub Command4_Click()
Label2.Caption = "李继尚个人签名"
Picture1.DrawWidth = 5 '可通过禁止该按钮的使用防止字体过大
Dim i As Integer
For i = 2 To 9
Picture1.PSet (i, 3), vbBlue '点的颜色
Next i
For i = 2 To 6
Picture1.PSet (6, i), vbBlue
Next i
For i = 4 To 8
Picture1.PSet (i, 6), vbBlue
Next i
Picture1.PSet (5, 4), vbBlue
Picture1.PSet (4, 5), vbBlue
Picture1.PSet (3, 6), vbBlue
Picture1.PSet (7, 4), vbBlue
Picture1.PSet (8, 5), vbBlue
Picture1.PSet (9, 6), vbBlue
Picture1.PSet (7, 7), vbBlue
For i = 8 To 11
Picture1.PSet (6, i), vbBlue
Next i
For i = 3 To 9
Picture1.PSet (i, 9), vbBlue
Next i
For i = 3 To 10
Picture1.PSet (14, i), vbBlue
Next i
For i = 11 To 13
Picture1.PSet (i, 6), vbBlue
Next i
Picture1.PSet (13, 3), vbBlue
Picture1.PSet (13, 4), vbBlue
For i = 11 To 13
Picture1.PSet (i, 8), vbBlue
Next i
Picture1.PSet (12, 7), vbBlue
Picture1.PSet (12, 9), vbBlue
Picture1.PSet (11, 10), vbBlue
Picture1.PSet (12, 5), vbBlue
For i = 15 To 19
Picture1.PSet (i, 6), vbBlue
Next i
For i = 3 To 9
Picture1.PSet (17, i), vbBlue
Next i
Picture1.PSet (15, 4), vbBlue
Picture1.PSet (16, 5), vbBlue
Picture1.PSet (19, 4), vbBlue
Picture1.PSet (18, 5), vbBlue
Picture1.PSet (16, 7), vbBlue
Picture1.PSet (15, 8), vbBlue
Picture1.PSet (18, 7), vbBlue
Picture1.PSet (19, 8), vbBlue
For i = 14 To 19
Picture1.PSet (i, 10), vbBlue
Next i
For i = 5 To 10
Picture1.PSet (23, i), vbBlue
Next i
Picture1.PSet (24, 4), vbBlue
Picture1.PSet (23, 3), vbBlue
Picture1.PSet (26, 4), vbBlue
Picture1.PSet (27, 3), vbBlue
Picture1.PSet (23, 5), vbBlue
Picture1.PSet (23, 10), vbBlue
For i = 5 To 10
Picture1.PSet (28, i), vbBlue
Next i
Picture1.PSet (27, 9), vbBlue
For i = 23 To 28
Picture1.PSet (i, 5), vbBlue
Next i
For i = 2 To 5
Picture1.PSet (25, i), vbBlue
Next i
Picture1.PSet (25, 7), vbBlue
Picture1.PSet (26, 7), vbBlue
Picture1.PSet (25, 8), vbBlue
Picture1.PSet (26, 8), vbBlue
End Sub

Private Sub Form_Load()
Text1 = ""
Text2 = ""
Command3.Enabled = False
Command4.Enabled = False
Label2.Caption = ""

End Sub

Private Sub Picture1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Text1 = X
Text2 = Y

End Sub
四、实验结果：

五、实验体会：
熟练运用visual basic，编写了简单的绘图程序。