vb.net 教程 5-7 Bitmap类 2- VB

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本节主要从代码介绍Bitmap的几个方法。

设计界面：

为了便于观察，请将PicDest的SizeMode设置为：AutoSize。

cbRotateFlip的Items属性设置为RotateFlipType的成员名称：

主要代码：

'窗体级变量，保存加载的图片
Dim sourceImg As Bitmap

'载入图片
Private Sub btnLoadimg_Click(sender As Object, e As EventArgs) Handles btnLoadimg.Click
sourceImg = New Bitmap("d:\15z.jpg")
'或者：
'sourceImg = Image.FromFile("d:\15z.jpg")
picSource.Image = sourceImg
End Sub

'旋转、翻转
Private Sub cbRotateFlip_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cbRotateFlip.SelectedIndexChanged
Dim destImg As Bitmap
destImg = sourceImg.Clone
Select Case cbRotateFlip.Text
Case "Rotate180FlipX"
destImg.RotateFlip(RotateFlipType.Rotate180FlipX)
Case "Rotate180FlipNone"
destImg.RotateFlip(RotateFlipType.Rotate180FlipNone)
Case "Rotate180FlipXY"
destImg.RotateFlip(RotateFlipType.Rotate180FlipXY)
Case "Rotate180FlipY"
destImg.RotateFlip(RotateFlipType.Rotate180FlipY)
Case "Rotate270FlipNone"
destImg.RotateFlip(RotateFlipType.Rotate270FlipNone)
Case "Rotate270FlipX"
destImg.RotateFlip(RotateFlipType.Rotate270FlipX)
Case "Rotate270FlipXY"
destImg.RotateFlip(RotateFlipType.Rotate270FlipXY)
Case "Rotate90FlipNone"
destImg.RotateFlip(RotateFlipType.Rotate90FlipNone)
Case "Rotate90FlipX"
destImg.RotateFlip(RotateFlipType.Rotate90FlipX)
Case "Rotate90FlipXY"
destImg.RotateFlip(RotateFlipType.Rotate90FlipXY)
Case "Rotate90FlipY"
destImg.RotateFlip(RotateFlipType.Rotate90FlipY)
Case "RotateNoneFlipNone"
destImg.RotateFlip(RotateFlipType.RotateNoneFlipNone)
Case "RotateNoneFlipX"
destImg.RotateFlip(RotateFlipType.RotateNoneFlipX)
Case "RotateNoneFlipXY"
destImg.RotateFlip(RotateFlipType.RotateNoneFlipXY)
Case "RotateNoneFlipY"
destImg.RotateFlip(RotateFlipType.RotateNoneFlipY)
End Select
picDest.Image = destImg
End Sub

'保存图片
Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
picDest.Image.Save("d:\1515.jpg", Imaging.ImageFormat.Jpeg)
End Sub