1.创建 .h 和 .m 文件，例如 CustomGradientView
CustomGradientView.h 文件应如下所示
@interface CustomGradientView : UIView
和 CustomGradientView.m 文件应如下所示 - (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
// color1 and color 2 u can take as u wish here i m taking for explaining
UIColor *color1=[UIColor whiteColor];
CGColorRef startColor =color1.CGColor;
UIColor *color2=[UIColor redColor];
CGColorRef endColor = color2.CGColor;
drawLinearGradient(context, rect, startColor, endColor);
//for rounded corners
CGPathRef p = [[UIBezierPath bezierPathWithRoundedRect:rect
5] CGPath];
CGContextAddRect(context, rect);
CGContextAddPath(context, p);
CGContextEOClip(context);
CGContextClearRect(context, rect);
}
然后在 .xib 文件中，您想要渐变的视图扩展其类 CustomGradientView 而不是 UIView
drawLinearGradient 方法在另一个类中，您必须将其导入它们
通用.h
#import <Foundation/Foundation.h>
void drawLinearGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef endColor);
CGRect rectFor1PxStroke(CGRect rect);
void draw1PxStroke(CGContextRef context, CGPoint startPoint, CGPoint endPoint, CGColorRef color);
void drawGlossAndGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef endColor);
static inline double radians (double degrees) { return degrees * M_PI/180; }
CGMutablePathRef createArcPathFromBottomOfRect(CGRect rect, CGFloat arcHeight);
CGMutablePathRef createRoundedRectForRect(CGRect rect, CGFloat radius);
和Common.m
#import "Common.h"
CGRect rectFor1PxStroke(CGRect rect) {
return CGRectMake(rect.origin.x + 0.5, rect.origin.y + 0.5, rect.size.width - 1, rect.size.height - 1);
}
void drawLinearGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef endColor) {
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat locations[] = { 0.0, 1.0 };
NSArray *colors = [NSArray arrayWithObjects:(__bridge id)startColor, (__bridge id)endColor, nil];
CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge 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);
}
void draw1PxStroke(CGContextRef context, CGPoint startPoint, CGPoint endPoint, CGColorRef color) {
CGContextSaveGState(context);
CGContextSetLineCap(context, kCGLineCapSquare);
CGContextSetStrokeColorWithColor(context, color);
CGContextSetLineWidth(context, 1.0);
CGContextMoveToPoint(context, startPoint.x + 0.5, startPoint.y + 0.5);
CGContextAddLineToPoint(context, endPoint.x + 0.5, endPoint.y + 0.5);
CGContextStrokePath(context);
CGContextRestoreGState(context);
}
void drawGlossAndGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef endColor) {
drawLinearGradient(context, rect, startColor, endColor);
CGColorRef glossColor1 = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.35].CGColor;
CGColorRef glossColor2 = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.1].CGColor;
CGRect topHalf = CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height/2);
drawLinearGradient(context, topHalf, glossColor1, glossColor2);
}
CGMutablePathRef createArcPathFromBottomOfRect(CGRect rect, CGFloat arcHeight) {
CGRect arcRect = CGRectMake(rect.origin.x, rect.origin.y + rect.size.height - arcHeight,
rect.size.width, arcHeight);
CGFloat arcRadius = (arcRect.size.height/2) + (pow(arcRect.size.width, 2) / (8*arcRect.size.height));
CGPoint arcCenter = CGPointMake(arcRect.origin.x + arcRect.size.width/2, arcRect.origin.y + arcRadius);
CGFloat angle = acos(arcRect.size.width / (2*arcRadius));
CGFloat startAngle = radians(180) + angle;
CGFloat endAngle = radians(360) - angle;
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddArc(path, NULL, arcCenter.x, arcCenter.y, arcRadius, startAngle, endAngle, 0);
CGPathAddLineToPoint(path, NULL, CGRectGetMaxX(rect), CGRectGetMinY(rect));
CGPathAddLineToPoint(path, NULL, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGPathAddLineToPoint(path, NULL, CGRectGetMinX(rect), CGRectGetMaxY(rect));
return path;
}
CGMutablePathRef createRoundedRectForRect(CGRect rect, CGFloat radius) {
