所以我有以下代码:
-
(void) drawLinearGradient:(CGRect) rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat locations[] = { 0.0, 0.3, 1.0 };
CGColorRef grayColor = [UIColor colorWithRed:37/255.f green:37/255.f
blue:37/255.f alpha:1.0].CGColor;
CGColorRef blueColor = [UIColor colorWithRed:23.0/255.0 green:171.0/255.0
blue:219.0/255.0 alpha:1.0].CGColor;
NSArray *colors = [NSArray arrayWithObjects: (id) grayColor, (id) grayColor, (id) blueColor, nil];
CGGradientRef gradient = CGGradientCreateWithColors(colorSpace,
(CFArrayRef) colors, locations);
CGPoint startPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMinY(rect));
CGPoint endPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect));
CGContextSaveGState(context);
CGContextAddRect(context, rect);
CGContextClip(context);
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, 0);
CGContextRestoreGState(context);
CGGradientRelease(gradient);
CGColorSpaceRelease(colorSpace);
}
这样做是从上到下绘制渐变,我怎样才能使它从左到右绘制?
答案 0 :(得分:6)
更改这两行:
CGPoint startPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMinY(rect));
CGPoint endPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect));
为:
CGPoint startPoint = CGPointMake(CGRectGetMinX(rect), CGRectGetMidY(rect));
CGPoint endPoint = CGPointMake(CGRectGetMaxX(rect), CGRectGetMidY(rect));