无法强制类型'System.Windows.Forms.Button'类型的对象类型'System.Windows.Forms.PictureBox'

Question

我试图对多个图片框执行相同的操作，但下面的代码的第一行正在生成这个错误：

Unable to cast object of type System.Windows.Forms.Button to type System.Windows.Forms.PictureBox 

所以我想知道是否有人可以帮助。提前致谢。

For Each pb As PictureBox In Me.Controls 
    Dim bp As New Bitmap(pb.Image) 
    pb.Region = GetRegion(bp, Color.FromArgb(255, 255, 0, 255)) 
    pb.Image = Nothing 
    pb.BackColor = Color.FromArgb(100, Color.Yellow) 
Next 

Answer 1

的For Each是遍历所有的控件在Me.Controls

您需要检查的PictureBox类型开始在控制操作之前

For Each ctrl As Control In Me.Controls 
    If TypeOf ctrl Is PictureBox Then 
     Dim bp As New Bitmap(ctrl.Image) 
     ctrl.Region = GetRegion(bp, Color.FromArgb(255, 255, 0, 255)) 
     ctrl.Image = Nothing 
     ctrl.BackColor = Color.FromArgb(100, Color.Yellow) 
    End If 
Next