如何向图像调整大小代码添加约束？即不大于165x146

Question

如何向图像调整大小代码添加约束？我希望图像不大于 165x146。当图像为 525x610 时，以下代码不保留约束

        intWidth = 165 '*** Fix Width ***'  
        intHeight = 146 '*** Fix Width ***' 

            If objGraphic.Width > intWidth Then
                Dim ratio As Double = objGraphic.Height / objGraphic.Width
                intHeight = ratio * intWidth
                objBitmap = New Bitmap(objGraphic, intWidth, intHeight)
            ElseIf objGraphic.Height > intHeight Then
                Dim ratio As Double = objGraphic.Width / objGraphic.Height
                intWidth = ratio * intHeight
                objBitmap = New Bitmap(objGraphic, intWidth, intHeight)
            Else
                objBitmap = New Bitmap(objGraphic)
            End If

Answer 1

我认为您想保持图像的纵横比？如果是这样，这个方法可能是合适的；您需要将宽度和高度乘以您获得的比率。

'define max size of image
intWidth = 165
intHeight = 146

'if the width/height is larger than the max, determine the appropriate ratio
Dim widthRatio as Double = Math.Min(1, intWidth / objGraphic.Width)
Dim heightRatio as Double = Math.Min(1, intHeight / objGraphic.Height)

'take the smaller of the two ratios as the one we will use to resize the image
Dim ratio as Double = Math.Min(widthRatio, heightRatio)

'apply the ratio to both the width and the height to ensure the aspect is maintained
objBitmap = New Bitmap(objGraphic, CInt(objGraphic.Width * ratio), CInt(objGraphic.Height * ratio))

编辑：可能需要将新的高度和宽度显式转换为整数