您好,
我正在使用Objective C for iPhone进行编程。我想改变Tab Bar项目的文字颜色。 ¿这可以吗?
非常感谢。
问候。
答案 0 :(得分:3)
在您的app委托文件中添加此内容 -
@interface UITabBar (ColorExtensions)
- (void)recolorItemsWithColor:(UIColor *)color shadowColor:(UIColor *)shadowColor shadowOffset:(CGSize)shadowOffset shadowBlur:(CGFloat)shadowBlur;
@end
@interface UITabBarItem (Private)
@property(retain, nonatomic) UIImage *selectedImage;
- (void)_updateView;
@end
@implementation UITabBar (ColorExtensions)
- (void)recolorItemsWithColor:(UIColor *)color shadowColor:(UIColor *)shadowColor shadowOffset:(CGSize)shadowOffset shadowBlur:(CGFloat)shadowBlur
{
CGColorRef cgColor = [color CGColor];
CGColorRef cgShadowColor = [shadowColor CGColor];
for (UITabBarItem *item in [self items])
if ([item respondsToSelector:@selector(selectedImage)] &&
[item respondsToSelector:@selector(setSelectedImage:)] &&
[item respondsToSelector:@selector(_updateView)])
{
CGRect contextRect;
contextRect.origin.x = 0.0f;
contextRect.origin.y = 0.0f;
contextRect.size = [[item selectedImage] size];
// Retrieve source image and begin image context
UIImage *itemImage = [item image];
CGSize itemImageSize = [itemImage size];
CGPoint itemImagePosition;
itemImagePosition.x = ceilf((contextRect.size.width - itemImageSize.width) / 2);
itemImagePosition.y = ceilf((contextRect.size.height - itemImageSize.height) / 2);
UIGraphicsBeginImageContext(contextRect.size);
CGContextRef c = UIGraphicsGetCurrentContext();
// Setup shadow
CGContextSetShadowWithColor(c, shadowOffset, shadowBlur, cgShadowColor);
// Setup transparency layer and clip to mask
CGContextBeginTransparencyLayer(c, NULL);
CGContextScaleCTM(c, 1.0, -1.0);
CGContextClipToMask(c, CGRectMake(itemImagePosition.x, -itemImagePosition.y, itemImageSize.width, -itemImageSize.height), [itemImage CGImage]);
//Setup the gradient...
//CGFloat components[8] = {0.0,0.4,1.0,0.2,0.0,0.6,1.0,1.0};
//CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
//CGGradientRef colorGradient = CGGradientCreateWithColorComponents(colorSpace, components, NULL, 2);
//CGContextDrawLinearGradient(c, colorGradient,CGPointZero,CGPointMake(0,contextRect.size.height),0);
// Fill and end the transparency layer
CGContextSetFillColorWithColor(c, cgColor);
contextRect.size.height = -contextRect.size.height;
CGContextFillRect(c, contextRect);
CGContextEndTransparencyLayer(c);
// Set selected image and end context
[item setSelectedImage:UIGraphicsGetImageFromCurrentImageContext()];
UIGraphicsEndImageContext();
// Update the view
[item _updateView];
}
}
然后您可以在应用程序中为标签栏指定颜色,并使用此代码完成启动 -
[[tabbarcontroller tabBar] recolorItemsWithColor:[UIColor colorWithRed:0.6640 green:0.1992 blue:0.1992 alpha:1.0] shadowColor:[UIColor clearColor] shadowOffset:CGSizeMake(0.0f, -1.0f) shadowBlur:3.0f];
答案 1 :(得分:0)
要做到这一点,你必须覆盖UITabBarController类,但如果你是新手我不会为此做出任何努力。在iOS开发中,最好学习iOS guidelines,因为最后您的应用将被Apple批准/拒绝审核。