ImageView.ScaleType 将图片边界缩放到所在view边界时的缩放选项. Options for scaling the bounds of an image to the bounds of this view. 不同选项含义 CENTER 居中,不缩放. Center the image in the view, but perform no scaling. CENTER_CROP 居中,如果图片宽或高比view小,就等比放大使得宽和高都大于等于view,计算时view大小减
原文链接:http://blog.csdn.net/pingchuanyang/article/details/9252689 取值为true时: Adjust the ImageView's bounds to preserve the aspect ration of its drawable. 调整ImageView的界限来保持图像纵横比不变. 这并不意味着ImageView的纵横比就一定和图像的纵横比相同 XML定义里的android:adjustViewBounds="true