[VB.NET]简单图形
简单图形
实例说明 在本实例中,我们将介绍使用最基本的绘图方法。在"绘图"菜单中可以选择画各种图形;在"选项"菜单中可以选择粗细、颜色等各种选项。程序运行结果如图63-1所示。 图63-1 运行结果 技术要点 l 矢量图形和位图图形的概念 l 绘制各种基本图形 实现过程 ■ 新建项目 打开Visual Studio.NET,选择"新建项目",在项目类型窗口中选择"Visual Basic项目",在模板窗口中,选择"Windows应用程序",在名称域中输入"DrawPic",然后选择保存路径。单击"确认"。 ■ 制作菜单 从工具箱中向窗体上添加一个MainMenu控件,并新建菜单项"文件"、"绘图"、"选项"三个主菜单。在文件菜单下有"打开","保存"等子菜单;在"绘图"菜单下面有"直线","椭圆","矩形","圆","圆弧"等子菜单。 ■ 添加代码 Dim DrawMode As Short Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs) Dim gf As Graphics = e.Graphics Dim newpen As New Pen(Color.Black,2) Select Case DrawMode Case 1 '画线 newpen.Color = Color.Cornsilk gf.DrawLine(newpen,50,200,200) Case 2 '画矩形 newpen.Color = Color.LawnGreen gf.DrawRectangle(newpen,10,20,170,180) Case 3 '画椭圆 newpen.Color = Color.Olive gf.DrawEllipse(newpen,180) Case 4 '画圆 newpen.Color = Color.PeachPuff gf.DrawEllipse(newpen,150,150) Case 5 '画圆弧 newpen.Color = Color.Maroon gf.DrawArc(newpen,300) End Select End Sub Private Sub mnuDrawLine_Click(ByVal sender As Object,ByVal e As System.EventArgs) Handles mnuDrawLine.Click DrawMode = 1 End Sub Private Sub mnuDrawRect_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles mnuDrawRect.Click DrawMode = 2 End Sub Private Sub mnuDrawEllip_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles mnuDrawEllip.Click DrawMode = 3 End Sub Private Sub mnuDrawCircle_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles mnuDrawCircle.Click DrawMode = 4 End Sub Private Sub mnuDrawArc_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles mnuDrawArc.Click DrawMode = 5 End Sub ■ 运行程序 单击菜单"调试|启动"或单击 图标运行程序。 小结 通过对本实例的学习,读者应该掌握了基本的画图原理和方法。对画点、线、矩形等各种形状的图形应该熟知于心。我们将在以后的实例中使用到这些方法。 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |