vb.net Bitmap 宽高问题

Question

1.我想问一下vb.net里面Bitmap的宽高的最大值是多少？超过最大值好像报错。。。。。

2.现在有两个Picturebox两个是紧挨着的。按住鼠标左键在picturebox1上面开始画图，不过鼠标左键不放，离开Picturebox1，进Picturebox2的时候Picturebox2上面什么都不显示。两个picturebox离开一个进入另外一个继续画怎么实现。。。。

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muradil

Answer 1

在两个picturebox的mousemove事件里判断是不是有鼠标左键被按下的情况，有就画图，没有就不画。

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Mike Feng [MSFT]
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Answer 2

情况不是左键被按下那么简单，因为你在一个picturebox里开始左键画的时候离开第一个picturebox的时候不会在第二个picturebox上面画。。。。

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muradil

Answer 3

那麻烦你再详细说明下你的情况有多么复杂.

>因为你在一个picturebox里开始左键画的时候离开第一个picturebox的时候不会在第二个picturebox上面画。。。。

你说的这句话到底是原因还是结果， 是你尝试后结果是没有在另一个picturebox上画，还是其他的？

又或许你是按右键开始画，而不是左键？

如果你尝试过我的建议， 那么可以贴出来你的代码吗？

另外我还想问， 你有实现picturebox2的图形该怎么画吗？ 如果没有，请按你的picturebox1里的方法在picturebox2里画图。

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Mike Feng [MSFT]
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Answer 4

Public Class Form1

    Private oldx, oldy As Integer

    Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            oldx = e.X
            oldy = e.Y
        End If
    End Sub


    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            If e.X > Me.PictureBox1.Width Then
                oldx = 0
                oldy = e.Y
                PictureBox2_MouseMove(sender, e)
            Else
                Dim g As Graphics = Me.PictureBox1.CreateGraphics
                g.DrawLine(Pens.Black, oldx, oldy, e.X, e.Y)
                oldx = e.X
                oldy = e.Y
            End If
        End If
    End Sub

    Private Sub PictureBox2_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox2.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Dim g As Graphics = Me.PictureBox2.CreateGraphics
            g.DrawLine(Pens.Black, oldx, oldy, e.X, e.Y)
            oldx = e.X
            oldy = e.Y
        End If

    End Sub
End Class

两个picturebox是紧挨着的（左右），你试一下我这个代码，我觉得你不太明白我的意思。。。超过picturebox1的右边界限的时候在picturebox2上面开始画，当然没有放鼠标左键。。。。。看一下我这个代码。。。。。麻烦你了

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muradil

Answer 5

试试这个代码：

    Dim flag As Boolean = True
    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            If e.X > Me.PictureBox1.Width + (Me.PictureBox2.Left - Me.PictureBox1.Right) Then
                If flag = True Then
                    oldx = e.X - PictureBox1.Width - (Me.PictureBox2.Left - Me.PictureBox1.Right)
                    oldy = e.Y
                End If
                flag = False
                Dim ee As New MouseEventArgs(e.Button, e.Clicks, e.X - PictureBox1.Width - (Me.PictureBox2.Left - Me.PictureBox1.Right), e.Y, e.Delta)
                PictureBox2_MouseMove(Nothing, ee)
            Else
                If flag = False Then
                    oldx = e.X + PictureBox1.Width + (Me.PictureBox2.Left - Me.PictureBox1.Right)
                End If
                flag = True
                Dim g As Graphics = Me.PictureBox1.CreateGraphics
                g.DrawLine(Pens.Black, oldx, oldy, e.X, e.Y)
                oldx = e.X
                oldy = e.Y
            End If
        End If
    End Sub

    Private Sub PictureBox2_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox2.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Dim g As Graphics = Me.PictureBox2.CreateGraphics
            g.DrawLine(Pens.Black, oldx, oldy, e.X, e.Y)
            oldx = e.X
            oldy = e.Y
        End If
    End Sub

以上代码实现了从picturebox1到2的连续画，你可以仿造着写从picturebox2到1的连续画

Best regards,

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Mike Feng [MSFT]
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Answer 6

特别说明下， 测试的时候请把1放在左边，2放在右边，并且他们在同一个水平高度.

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Mike Feng [MSFT]
MSDN Community Support | Feedback to us
Get or Request Code Sample from Microsoft
Please remember to mark the replies as answers if they help and unmark them if they provide no help.