C＃protected override void“当前上下文中不存在”

Question

我有一个类，我为控件OnPaint覆盖Button，它给了我一个错误

  

图形G在当前上下文中不存在

但我已经定义了图形G.

abstract class ThemeContainer154 : Control
{
   #region " Initialization "
   protected Graphics G;
   protected Bitmap B;

public ThemeContainer154()
{
   SetStyle((ControlStyles)139270, true);

   _ImageSize = Size.Empty;
   Font = new Font("Verdana", 8);

   MeasureBitmap = new Bitmap(1, 1);
   MeasureGraphics = Graphics.FromImage(MeasureBitmap);

   DrawRadialPath = new GraphicsPath();

   InvalidateCustimization();
}

这是“主题”：

class NSButton : Control
{
   protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
   {
      G = e.Graphics;
  G.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
      G.Clear(BackColor);
  G.SmoothingMode = SmoothingMode.AntiAlias;
   }
}

我得到的错误是：

 The name 'G' does not exist in the current context

Answer 1

NSButton不继承ThemeContainer154。

更改

class NSButton : Control

到

class NSButton : ThemeContainer154