UINavigationBar渐变细节 [英] UINavigationBar gradient details
本文介绍了UINavigationBar渐变细节的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试重新创建UINavigationBar的外观。使用渐变绘制条形图的背景,但不清楚其中的默认颜色和点是什么。有没有人在这方面做过什么?
I'm trying to recreate the look of a UINavigationBar. The background of the bar is drawn using a gradient, but it's unclear exactly what the default colors and points are in it. Has anyone done anything in this area?
推荐答案
来自我的一个项目。根据自己的喜好调整颜色。它还可以显示背景图像(imageReady),否则它会像Apple的那样绘制导航栏
From one of my projects. Adjust the colors to your liking. It also can show a background image if you want (imageReady), else it draws the navbar like Apple's
// #Lighter r,g,b,a #Darker r,g,b,a
#define MAIN_COLOR_COMPONENTS { 0.153, 0.306, 0.553, 1.0, 0.122, 0.247, 0.482, 1.0 }
#define LIGHT_COLOR_COMPONENTS { 0.478, 0.573, 0.725, 1.0, 0.216, 0.357, 0.584, 1.0 }
@implementation UINavigationBar (UINavigationBarCategory)
- (void)drawRect:(CGRect)rect {
if (imageReady) {
UIImage *img = [UIImage imageNamed: @"navigation_background.png"];
[img drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
} else {
// Render yourself instead.
// You will need to adjust the MAIN_COLOR_COMPONENTS and LIGHT_COLOR_COMPONENTS to match your app
// emulate the tint colored bar
CGContextRef context = UIGraphicsGetCurrentContext();
CGFloat locations[2] = { 0.0, 1.0 };
CGColorSpaceRef myColorspace = CGColorSpaceCreateDeviceRGB();
CGFloat topComponents[8] = LIGHT_COLOR_COMPONENTS;
CGGradientRef topGradient = CGGradientCreateWithColorComponents(myColorspace, topComponents, locations, 2);
CGContextDrawLinearGradient(context, topGradient, CGPointMake(0, 0), CGPointMake(0,self.frame.size.height/2), 0);
CGGradientRelease(topGradient);
CGFloat botComponents[8] = MAIN_COLOR_COMPONENTS;
CGGradientRef botGradient = CGGradientCreateWithColorComponents(myColorspace, botComponents, locations, 2);
CGContextDrawLinearGradient(context, botGradient,
CGPointMake(0,self.frame.size.height/2), CGPointMake(0, self.frame.size.height), 0);
CGGradientRelease(botGradient);
CGColorSpaceRelease(myColorspace);
// top Line
CGContextSetRGBStrokeColor(context, 1, 1, 1, 1.0);
CGContextMoveToPoint(context, 0, 0);
CGContextAddLineToPoint(context, self.frame.size.width, 0);
CGContextStrokePath(context);
// bottom line
CGContextSetRGBStrokeColor(context, 0, 0, 0, 1.0);
CGContextMoveToPoint(context, 0, self.frame.size.height);
CGContextAddLineToPoint(context, self.frame.size.width, self.frame.size.height);
CGContextStrokePath(context);
}
}
@end
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