设置UIButton的文字居右显示 去掉点击默认置灰效果
1.设置UIButton的文字居右显示
[button setContentHorizontalAlignment:UIControlContentHorizontalAlignmentRight];
2.去掉点击默认置灰效果
[button setAdjustsImageWhenHighlighted:NO]; // default is YES. if YES, image is drawn darker when highlighted(pressed)