继承 UIControl
一. 初始化
初始化方法
+ (instancetype)buttonWithType:(UIButtonType)buttonType;
UIButtonType枚举如下:
typedef NS_ENUM(NSInteger, UIButtonType) {
UIButtonTypeCustom = 0, // no button type
UIButtonTypeSystem NS_ENUM_AVAILABLE_IOS(7_0), //标注系统按钮
UIButtonTypeDetailDisclosure, // 感叹号❗️图标
UIButtonTypeInfoLight, // 感叹号❗️图标
UIButtonTypeInfoDark, // 感叹号❗️图标
UIButtonTypeContactAdd,// ➕加号️图标
UIButtonTypePlain API_AVAILABLE(tvos(11.0)) API_UNAVAILABLE(ios, watchos), // standard system button without the blurred background view
UIButtonTypeRoundedRect = UIButtonTypeSystem // Deprecated, use UIButtonTypeSystem instead
};
初始化
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
二. 关于UIButton的UIEdgeInsets属性
我们在实际工作当中设计妹妹经常会设计图文共存的button,如下图
image
上image下title, 或者左title又image,这时我们就会用到UIButton的UIEdgeInsets属性
UIButton 共有三个相关属性:
- contentEdgeInsets
- titleEdgeInsets
- imageEdgeInsets
先科普一下UIEdgeInsets
它是结构体,四个参数:top 上边界, left 左边界, bottom 下边界, right 右边界, 默认均为0
typedef struct UIEdgeInsets {
CGFloat top, left, bottom, right; // specify amount to inset (positive) for each of the edges. values can be negative to 'outset'
} UIEdgeInsets;
1. contentEdgeInsets
如果给按钮设置contentEdgeInsets属性，就是按钮的内容整体（包含UILabel和UIImageView）进行偏移.
先创建一个一个button, 如下图:
image
//默认图左字右
UIButton *edgeInsetsBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[edgeInsetsBtn setTitle:@"edgeInsets" forState:UIControlStateNormal];
[edgeInsetsBtn setImage:[UIImage imageNamed:@"icon_globe"] forState:UIControlStateNormal];
edgeInsetsBtn.backgroundColor = [UIColor blueColor];
edgeInsetsBtn.frame = CGRectMake(100, 100, 150, 150);
[self.view addSubview:edgeInsetsBtn];
CGFloat imageWidth = edgeInsetsBtn.imageView.bounds.size.width;
CGFloat titleWidth = edgeInsetsBtn.titleLabel.bounds.size.width;
CGFloat imageHeight = edgeInsetsBtn.imageView.bounds.size.height;
CGFloat titleHeight = edgeInsetsBtn.titleLabel.bounds.size.height;
按钮内容整体向右下分别移动20像素：
[edgeInsetsBtn setContentEdgeInsets:UIEdgeInsetsMake(20, 20, -20, -20)];
image
2. titleEdgeInsets & imageEdgeInsets
image的UIEdgeInsets属性的top，left，bottom都是相对于按钮的，right是相对于title；
title的UIEdgeInsets属性的top，bottom，right都是相对按钮的，left是相对于image；
title在左，image在右：
image
edgeInsetsBtn.titleEdgeInsets = UIEdgeInsetsMake(0, -imageWidth, 0, imageWidth);
edgeInsetsBtn.imageEdgeInsets = UIEdgeInsetsMake(0, titleWidth, 0, -titleWidth);
上图下字:
image
edgeInsetsBtn.imageEdgeInsets = UIEdgeInsetsMake(-imageHeight/2, titleWidth/2, imageHeight/2, -titleWidth/2);
edgeInsetsBtn.titleEdgeInsets = UIEdgeInsetsMake(titleHeight/2, -imageWidth/2, -titleHeight/2, imageWidth/2);
