IOS_UIButton去掉系统的按下高亮置灰效果

第一种方法：

setAdjustsImageWhenHighlighted   // default is YES. if YES, image is drawn darker when highlighted(pressed)

 UIButton *priceBtn = [UIButton buttonWithType:UIButtonTypeCustom];
  [priceBtn setTag:PRICE_BTN_TAG];
  [priceBtn setFrame:CGRectMake(DISTANCE_OF_SCREEN_BORDER, 3, 63, 31.5)];
  [priceBtn setBackgroundColor:[UIColor clearColor]];
  [priceBtn setImage:[UIImage imageNamed:@"sequence_up_pressed.png"] forState:UIControlStateNormal];
  [priceBtn addTarget:self action:@selector(priceBtnClicked:) forControlEvents:UIControlEventTouchUpInside];
  [priceBtn setAdjustsImageWhenHighlighted:NO];

相关属性：

@property(nonatomic)         BOOL         reversesTitleShadowWhenHighlighted;  // default is NO. if YES, shadow reverses to shift between engrave and emboss appearance

@property(nonatomic)         BOOL         adjustsImageWhenHighlighted;   // default is YES. if YES, image is drawn darker when highlighted(pressed)

@property(nonatomic)         BOOL         adjustsImageWhenDisabled;      // default is YES. if YES, image is drawn lighter when disabled

@property(nonatomic)         BOOL         showsTouchWhenHighlighted;     // default is NO. if YES, show a simple feedback (currently a glow) while highlighted

第二种方法：

本群的Misery-iOS-武汉提到了一个巧妙的方法  正常&高亮用相同的图片

 [priceBtn setImage:[UIImage imageNamed:@"sequence_up_pressed.png"] forState:UIControlStateNormal];
 [priceBtn setImage:[UIImage imageNamed:@"sequence_up_pressed.png"] forState:UIControlStateHighlighted];