图片圆角设置

//圆角设置

imageView.layer.cornerRadius = 8;(值越大，角就越圆)

imageView.layer.masksToBounds = YES;

//边框宽度及颜色设置

[imageView.layer setBorderWidth:2];

[imageView.layer setBorderColor:[UIColor blueColor]];
//设置边框为蓝色

//自动适应,保持图片宽高比

imageView.contentMode = UIViewContentModeScaleAspectFit;