button.contentHorizontalAlignment=UIControlContentHorizontalAlignmentLeft;
//按钮包裹 [button sizeToFit];//文字往外偏移 button.contentEdgeInsets=UIEdgeInsetsMake(0, -100, 0, 0);
按钮文字向左对齐
原文：http://www.cnblogs.com/xiezefeng/p/5463366.html
