// ----------------------------------UIButton------------------------------
// UIButtonTypeSystem 点击文字会有效果,变色 UIButtonTypeCustom 无点击效果
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(200, 100, 200, 80);
[button setTitle:@"click me" forState:UIControlStateNormal];
button.backgroundColor = [UIColor blueColor];
[button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[button setTitleColor:[UIColor whiteColor] forState:UIControlStateSelected];
// 字体大小
button.titleLabel.font = [UIFont systemFontOfSize: 20.0];
// button.font = [UIFont systemFontOfSize:20]; 废弃
//边框
button.layer.borderWidth = 3;
button.layer.borderColor = [UIColor grayColor].CGColor;
// 设置圆角
[button.layer setMasksToBounds:YES];
[button.layer setCornerRadius:20.0];
// 按下会有发光的效果
button.showsTouchWhenHighlighted = YES;
// 文字居左
button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
// 文字居顶
button.contentVerticalAlignment = UIControlContentVerticalAlignmentTop;
// 文字内边距
button.contentEdgeInsets = UIEdgeInsetsMake(10, 10, 0, 0);
[button addTarget:self action:@selector(click) forControlEvents:UIControlEventTouchUpInside];