.net 无法使colormatrix和透明度正常工作

我正在做一个RTS风格的游戏，学习更多关于使用类、继承和接口编程的知识——进展顺利，没有什么大问题

我遇到的问题是颜色矩阵。在地图上放置单位时，我使用颜色矩阵添加绿色或红色覆盖，具体取决于位置的有效性。同样，使用下面的代码（为了清晰起见，将代码切掉）也可以正常工作。但我也想让图像半透明

Public Overrides Function GetCurrentFrame() As Image
    _AnimationFrame += _AnimationFrameTime
    If _AnimationFrame > 5 Then _AnimationFrame = 0
    Dim CurrentFrame As Image = Nothing

    CurrentFrame = My.Resources.ResourceManager.GetObject("dragoon_walk_l_" & Convert.ToInt16(_AnimationFrame).ToString)

    Dim g As Graphics = Graphics.FromImage(CurrentFrame)

    Dim cm As System.Drawing.Imaging.ColorMatrix = New System.Drawing.Imaging.ColorMatrix(New Single()() _
         {New Single() {0.3, 0.3, 0.3, 0, 0}, _
        New Single() {0.59, 0.59, 0.59, 0, 0}, _
        New Single() {0.11, 0.11, 0.11, 0, 0}, _
        New Single() {0, 0, 0, 1, 0}, _
        New Single() {0.5, 0, 0, 0.5, 1}})

    Dim ia As System.Drawing.Imaging.ImageAttributes = New System.Drawing.Imaging.ImageAttributes()
    ia.SetColorMatrix(cm)
    g.DrawImage(CurrentFrame, New Rectangle(0, 0, CurrentFrame.Width, CurrentFrame.Height), 0, 0, CurrentFrame.Width, CurrentFrame.Height, GraphicsUnit.Pixel, ia)

    g.DrawImage(My.Resources.ResourceManager.GetObject("health" & (Int(20 * (_UnitHealth / _UnitHealthMax)) - 1).ToString), 0, 14)
    g.DrawImage(My.Resources.ResourceManager.GetObject("level" & _Level.ToString), 6, 0)
    g.Dispose()
    Return CurrentFrame
End Function

这是我正在使用的代码，它首先使单位灰度化，然后将其染成红色，但不使其半透明

Public Overrides Function GetCurrentFrame() As Image
    _AnimationFrame += _AnimationFrameTime
    If _AnimationFrame > 5 Then _AnimationFrame = 0
    Dim CurrentFrame As Image = Nothing

    CurrentFrame = My.Resources.ResourceManager.GetObject("dragoon_walk_l_" & Convert.ToInt16(_AnimationFrame).ToString)

    Dim g As Graphics = Graphics.FromImage(CurrentFrame)

    Dim cm As System.Drawing.Imaging.ColorMatrix = New System.Drawing.Imaging.ColorMatrix(New Single()() _
         {New Single() {0.3, 0.3, 0.3, 0, 0}, _
        New Single() {0.59, 0.59, 0.59, 0, 0}, _
        New Single() {0.11, 0.11, 0.11, 0, 0}, _
        New Single() {0, 0, 0, 1, 0}, _
        New Single() {0.5, 0, 0, 0.5, 1}})

    Dim ia As System.Drawing.Imaging.ImageAttributes = New System.Drawing.Imaging.ImageAttributes()
    ia.SetColorMatrix(cm)
    g.DrawImage(CurrentFrame, New Rectangle(0, 0, CurrentFrame.Width, CurrentFrame.Height), 0, 0, CurrentFrame.Width, CurrentFrame.Height, GraphicsUnit.Pixel, ia)

    g.DrawImage(My.Resources.ResourceManager.GetObject("health" & (Int(20 * (_UnitHealth / _UnitHealthMax)) - 1).ToString), 0, 14)
    g.DrawImage(My.Resources.ResourceManager.GetObject("level" & _Level.ToString), 6, 0)
    g.Dispose()
    Return CurrentFrame
End Function

---

为了澄清，问题是如何使用彩色矩阵使我的图像变成红色和半透明。

我已经看了两天了，我刚刚想到了这一点

问题是我是从原始图像创建位图的，而不是空白位图。正在返回图像而不是位图：(

这就是我使用的解决方案

Public Overrides Function GetCurrentFrame() As Image
    _AnimationFrame += _AnimationFrameTime
    If _AnimationFrame > 5 Then _AnimationFrame = 0
    Dim CurrentFrame As Image = Nothing

    CurrentFrame = My.Resources.ResourceManager.GetObject("dragoon_walk_l_" & Convert.ToInt16(_AnimationFrame).ToString)

    Dim bm As Bitmap = New Bitmap(CurrentFrame.Width, CurrentFrame.Height)
    Dim g As Graphics = Graphics.FromImage(bm)

    Dim cm As System.Drawing.Imaging.ColorMatrix = New System.Drawing.Imaging.ColorMatrix(New Single()() _
         {New Single() {.3, .3, .3, 0, 0}, _
        New Single() {0.59, .59,.59, 0, 0}, _
        New Single() {.1, 0.1, 0.1, 0, 0}, _
        New Single() {0, 0, 0, 0.75, 0}, _
        New Single() {0.5, 0, 0, 0, 1}})

    Dim ia As System.Drawing.Imaging.ImageAttributes = New System.Drawing.Imaging.ImageAttributes()
    ia.SetColorMatrix(cm)
    g.DrawImage(CurrentFrame, New Rectangle(0, 0, CurrentFrame.Width, CurrentFrame.Height), 0, 0, CurrentFrame.Width, CurrentFrame.Height, GraphicsUnit.Pixel, ia)

    g.DrawImage(My.Resources.ResourceManager.GetObject("health" & (Int(20 * (_UnitHealth / _UnitHealthMax)) - 1).ToString), 0, 14)
    g.DrawImage(My.Resources.ResourceManager.GetObject("level" & _Level.ToString), 6, 0)
    g.Dispose()
    Return bm
End Function