.NET Compact Framework的二维图形引擎应用(4)

//Clear the background and reset the transform state
gx.Clear(Color.White);
gx.ResetTransform();
//Fill a rectangle with a black-white LinearGradientBrushX
Rectangle r = new Rectangle(20, 50, 300, 100);
Color c1 = Color.Black;
Color c2 = Color.White;
BrushX brush1 = new LinearGradientBrushX(r, c1, c2, 30F);
gx.FillRectangle(brush1, r);
//Fill a rectangle with a 7-color LinearGradientBrushX 
r = new Rectangle(90, 100, 150, 100);
LinearGradientBrushX br = new LinearGradientBrushX(r,Color.Black,Color.Black, 60F); 
ColorBlendX cb = new ColorBlendX(); 
cb.Positions=new float[7]; 
int i=0; 
for(float f=0;f<=1;f+=1.0f/6) 
cb.Positions[i++]=f; 
cb.Colors=new Color[]
{Color.Red,Color.Orange,Color.Yellow,Color.Green,Color.Blue,Color.Indigo,Color.Violet}; 
br.InterpolationColors=cb; 
gx.TranslateTransform(160, 10);
gx.RotateTransform(60F);
gx.FillRectangle(br, r);
//Fill a rectangle with a 7-color RadialGradientBrushX 
r.Y += 50;
RadialGradientBrushX brush2 = new RadialGradientBrushX(r, 
  Color.Black,Color.Black, 220F); 
brush2.InterpolationColors = cb;
gx.RotateTransform(-45F);
gx.TranslateTransform(-200, -170);
gx.FillRectangle(brush2, r);
//Refresh
Invalidate();