如何在iPhone sdk中获取彩色图像

Question

I want something as follows

UIImage *solid = [UIImage imageWithColor:[UIColor darkGrayColor]];

to create an image with respect to some color.

how to do it in iPhone sdk.

Answer 1

You can draw the color into a CGContext and then capture an image from it:

- (UIImage *)imageWithColor:(UIColor *)color andSize:(CGSize)size {
  //Create a context of the appropriate size
  UIGraphicsBeginImageContext(size);
  CGContextRef currentContext = UIGraphicsGetCurrentContext();

  //Build a rect of appropriate size at origin 0,0
  CGRect fillRect = CGRectMake(0,0,size.width,size.height);

  //Set the fill color
  CGContextSetFillColorWithColor(currentContext, color.CGColor);

  //Fill the color
  CGContextFillRect(currentContext, fillRect);

  //Snap the picture and close the context
  UIImage *retval = UIGraphicsGetImageFromCurrentImageContext(void);
  UIGraphicsEndImageContext();

  return retval;
}

Answer 2

If you're just trying to create a solid rectangle of colour why not just do something like

UIView *solid = [[UIView alloc] initWithFrame:someFrame];
solid.backgroundColor = [UIColor greyColor];

And then add the view to whatever subview you want to show the solid colour.

(That is, of course only if that's what you're trying to achieve. Maybe you aren't)