UIButton按钮的图片按比例缩放

视觉给的图片比较大，但是，用在按钮上显示过大怎么办？

1.设置按钮的imageEdgeInsets，比如设置上下间距，从而设置图片的高度。

UIEdgeInsets UIEdgeInsetsMake(CGFloat top, CGFloat left, CGFloat bottom, CGFloat right) {
    UIEdgeInsets insets = {top, left, bottom, right};
    return insets;
}

2.设置按钮图片的拉伸属性UIViewContentMode;中的UIViewContentModeScaleAspectFit，按最小边填充

typedef NS_ENUM(NSInteger, UIViewContentMode) {
    UIViewContentModeScaleToFill,
    UIViewContentModeScaleAspectFit,      // contents scaled to fit with fixed aspect. remainder is transparent
    UIViewContentModeScaleAspectFill,     // contents scaled to fill with fixed aspect. some portion of content may be clipped.
};

3.代码设置

    UIButton *kfButton = [UIButton buttonWithType:UIButtonTypeCustom];
    kfButton.frame = CGRectMake((self.view.bounds.size.width-136)*0.5, 200, 136, 40);
    kfButton.imageEdgeInsets = UIEdgeInsetsMake(13, -10, 13, 0);
    kfButton.titleEdgeInsets = UIEdgeInsetsMake(0, -5, 0, 0);
    [kfButton setTitle:@"xxx在线客服" forState:UIControlStateNormal];
    [kfButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [kfButton setImage:[UIImage imageNamed:@"search_search_service"] forState:UIControlStateNormal];
    kfButton.imageView.contentMode = UIViewContentModeScaleAspectFit;
    kfButton.layer.cornerRadius = 3;
    kfButton.layer.borderWidth = 1;
    kfButton.layer.masksToBounds = YES;
    kfButton.titleLabel.font = [UIFont systemFontOfSize:14];
    [kfButton addTarget:self action:@selector(kfButtonClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:kfButton];

4.效果展示

image.png