可能的 g.Transform 用法

Question

我将以下输出到图片框中，我想将其归入图像的特定部分，以便我可以放大该部分。我对 Transform 属性不太熟悉，我想知道我是否正在接近我试图正确实现的目标。如果你看下面的图片，整个图像都在图片盒表面上，而我放在那里的方形黑框，我想把焦点放在它上面，让它填满图片盒，本质上是放大的。希望我能把自己说清楚。

Note：此问题总结整理于:Possible g.Transform usage

Answer 1

我们如何像旧网站一样找到我在这里发布的所有帖子？

您可以在“活动”中看到它们。

对于图片缩放，还要检查： https://www.codeproject.com/Articles/21097/PictureBox-Zoom 在 Visual Basic 中，代码如下所示：

复制

    Private _ZoomFactor As Integer  
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load  
        TrackBar1.Minimum = 1  
        TrackBar1.Maximum = 3  
        TrackBar1.Value = 2  
        _ZoomFactor = TrackBar1.Value  
        PictureBox2.SizeMode = PictureBoxSizeMode.StretchImage  
        PictureBox1.Image = Image.FromFile("your picture path")  
    End Sub  
    Private Sub TrackBar1_ValueChanged(sender As Object, e As EventArgs) Handles TrackBar1.ValueChanged  
        _ZoomFactor = TrackBar1.Value  
        Label1.Text = String.Format("x{0}", _ZoomFactor)  
    End Sub  
  
    Private Sub PictureBox1_MouseMove(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseMove  
        If PictureBox1.Image Is Nothing Then Return  
        UpdateZoomedImage(e)  
    End Sub  
    Private Sub UpdateZoomedImage(ByVal e As MouseEventArgs)  
        Dim zoomWidth As Integer = PictureBox2.Width / _ZoomFactor  
        Dim zoomHeight As Integer = PictureBox2.Height / _ZoomFactor  
        Dim halfWidth As Integer = zoomWidth / 2  
        Dim halfHeight As Integer = zoomHeight / 2  
        Dim tempBitmap As Bitmap = New Bitmap(zoomWidth, zoomHeight, PixelFormat.Format24bppRgb)  
        Dim bmGraphics As Graphics = Graphics.FromImage(tempBitmap)  
        bmGraphics.InterpolationMode = InterpolationMode.HighQualityBicubic  
        bmGraphics.DrawImage(PictureBox1.Image, New Rectangle(0, 0, zoomWidth, zoomHeight), New Rectangle(e.X - halfWidth, e.Y - halfHeight, zoomWidth, zoomHeight), GraphicsUnit.Pixel)  
        PictureBox2.Image = tempBitmap  
        bmGraphics.DrawLine(Pens.Black, halfWidth + 1, halfHeight - 4, halfWidth + 1, halfHeight - 1)  
        bmGraphics.DrawLine(Pens.Black, halfWidth + 1, halfHeight + 6, halfWidth + 1, halfHeight + 3)  
        bmGraphics.DrawLine(Pens.Black, halfWidth - 4, halfHeight + 1, halfWidth - 1, halfHeight + 1)  
        bmGraphics.DrawLine(Pens.Black, halfWidth + 6, halfHeight + 1, halfWidth + 3, halfHeight + 1)  
        bmGraphics.Dispose()  
        PictureBox2.Refresh()  
    End Sub  

我的测试结果。 希望对您有所帮助。

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