介绍两种管理UIButton中的Image和Title的方法
1、自定义UIButton
#import "BBImageButton.h"
@implementation BBImageButton
- (instancetype)initWithTitle:(NSString *)title
{
self = [super initWithFrame:CGRectZero];
if (self) {
[self setTitle:title forState:UIControlStateNormal];
[self setImage:[UIImage imageNamed:@"navigationbar_arrow_down"] forState:UIControlStateNormal];
[self setImage:[UIImage imageNamed:@"navigationbar_arrow_up"] forState:UIControlStateSelected];
// 设置button为Selected状态时，点击button时，图片不出现闪动
[self setImage:[UIImage imageNamed:@"navigationbar_arrow_up"] forState:(UIControlStateSelected | UIControlStateHighlighted)];
}
return self;
}
- (void)layoutSubviews
{
[super layoutSubviews];
self.imageView.frame = CGRectMake(0, 0, CGRectGetWidth(self.imageView.frame), CGRectGetHeight(self.imageView.frame));
self.imageView.center = CGPointMake(CGRectGetWidth(self.frame) / 2, self.imageView.center.y);
self.titleLabel.frame = CGRectMake(0, CGRectGetMaxY(self.imageView.frame) + 10, CGRectGetWidth(self.titleLabel.frame), CGRectGetHeight(self.titleLabel.frame));
self.titleLabel.center = CGPointMake(self.imageView.center.x, self.titleLabel.center.y);
}
@end
如下图所示：
6.png
左右布局
- (void)layoutSubviews
{
[super layoutSubviews];
CGFloat x = CGRectGetWidth(self.frame) * 0.5 - (CGRectGetWidth(self.titleLabel.frame) - CGRectGetWidth(self.imageView.frame));
self.titleLabel.frame = CGRectMake(x, self.titleLabel.frame.origin.y, CGRectGetWidth(self.titleLabel.frame), CGRectGetHeight(self.titleLabel.frame));
self.imageView.frame = CGRectMake(CGRectGetMaxX(self.titleLabel.frame), self.imageView.frame.origin.y, CGRectGetWidth(self.imageView.frame), CGRectGetHeight(self.imageView.frame));
}
7.png
在这里面有个小技巧，如果想要文字跟图片有一定间距的话，不一定非得改变它的坐标，可以在title赋值的时候这样处理，“加一个空格”，作为程序猿,我们不应该放弃任何一个偷懒的机会。
title = [NSString stringWithFormat:@"%@ ", title];
8.png
2、UIButton中的titleEdgeInsets和imageEdgeInsets可以管理button中image和title的布局。
默认情况下,是图片在左,文字在右,垂直居中显示,如下图:
button.titleEdgeInsets = UIEdgeInsetsZero;
button.imageEdgeInsets = UIEdgeInsetsZero;
1.png
设置如下布局后,图片和文字都居中显示。
button.titleEdgeInsets = UIEdgeInsetsMake(0, -button.imageView.frame.size.width, 0, 0);
// button.imageEdgeInsets = UIEdgeInsetsMake(0, 0, 0, button.titleLabel.frame.size.width);
// 由于iOS8中titleLabel的size为0，用上面这样设置有问题，修改一下即可
button.imageEdgeInsets = UIEdgeInsetsMake(0, 0, 0, -button.titleLabel.intrinsicContentSize.width);
2.png
如果想图片在上,文字在下,水平居中显示,则按下面设置即可:
button.titleEdgeInsets = UIEdgeInsetsMake(0, -button.imageView.frame.size.width, -button.imageView.frame.size.height, 0);
// button.imageEdgeInsets = UIEdgeInsetsMake(-button.titleLabel.frame.size.height, 0, 0, -button.titleLabel.frame.size.width);
// 由于iOS8中titleLabel的size为0，用上面这样设置有问题，修改一下即可
button.imageEdgeInsets = UIEdgeInsetsMake(-button.titleLabel.intrinsicContentSize.height, 0, 0, -button.titleLabel.intrinsicContentSize.width);
3.png
如果觉得图片和文字离的太近了，稍微分开一点：
CGFloat offset = 40.0f;
button.titleEdgeInsets = UIEdgeInsetsMake(0, -button.imageView.frame.size.width, -button.imageView.frame.size.height-offset/2, 0);
// button.imageEdgeInsets = UIEdgeInsetsMake(-button.titleLabel.frame.size.height-offset/2, 0, 0, -button.titleLabel.frame.size.width);
// 由于iOS8中titleLabel的size为0，用上面这样设置有问题，修改一下即可
button.imageEdgeInsets = UIEdgeInsetsMake(-button.titleLabel.intrinsicContentSize.height-offset/2, 0, 0, -button.titleLabel.intrinsicContentSize.width);
4.png
文字左对齐，图片右对齐
button.titleEdgeInsets = UIEdgeInsetsMake(0, -button.imageView.frame.size.width - button.frame.size.width + button.titleLabel.intrinsicContentSize.width, 0, 0);
button.imageEdgeInsets = UIEdgeInsetsMake(0, 0, 0, -button.titleLabel.frame.size.width - button.frame.size.width + button.imageView.frame.size.width);
5.png
