窗体级的变量
isPick:标识是否开始取色
bmp:不可见的bitmap,保存了当前屏幕的截图
Dim isPick As Boolean Dim bmp As Bitmap
Private Sub btnPick_MouseDown(sender As Object,e As MouseEventArgs) Handles btnPick.MouseDown If e.Button = MouseButtons.Left Then isPick = True Dim Scr As Screen = Screen.PrimaryScreen Dim recSc As Rectangle = Scr.Bounds bmp = New Bitmap(recSc.Width,recSc.Height) Dim g As Graphics = Graphics.FromImage(bmp) g.copyFromScreen(New Point(0,0),New Point(0,New Size(recSc.Width,recSc.Height)) Me.Cursor = Cursors.Cross End If End Sub
鼠标移动的时候我们要做的工作
1、获得鼠标坐标位置
2、将鼠标坐标转换为屏幕坐标,通过控件的PointToScreen()方法完成
3、对bmp坐标点取色,通过GetPixel()方法完成
4、附加对颜色的RGB值做了简单分析
1、获得鼠标坐标位置
2、将鼠标坐标转换为屏幕坐标,通过控件的PointToScreen()方法完成
3、对bmp坐标点取色,通过GetPixel()方法完成
4、附加对颜色的RGB值做了简单分析
Private Sub btnPick_MouseMove(sender As Object,e As MouseEventArgs) Handles btnPick.MouseMove Dim x,y As Integer Dim p As Point = New Point(e.X,e.Y) Dim colorPoint As Color Dim r,g,b As Byte If isPick = True Then x = btnPick.PointToScreen(p).X y = btnPick.PointToScreen(p).Y lblLocation.Text = "x:" & x & " y:" & y colorPoint = bmp.GetPixel(x,y) picPalette.BackColor = colorPoint r = colorPoint.R g = colorPoint.G b = colorPoint.B hsbRed.Value = r hsbGreen.Value = g hsbBlue.Value = b lblRed.Text = r.ToString lblGreen.Text = g.ToString lblBlue.Text = b.ToString Call toWebColor() End If End Sub
Private Sub btnPick_MouseUp(sender As Object,e As MouseEventArgs) Handles btnPick.MouseUp isPick = False Me.Cursor = Cursors.Default End Sub
当鼠标左键在“取色”按钮上按下不放时,移动鼠标就可以在屏幕上取色了。如下图:
由于.net平台下C#和vb.NET很相似,本文也可以为C#爱好者提供参考。
学习更多vb.net知识,请参看 vb.net 教程 目录