//设置UIButton在点按住时附带高亮效果_addMusicBtn.showsTouchWhenHighlighted = YES;
[_addMusicBtn addTarget:self action:@selector(addMusicAction:) forControlEvents:UIControlEventTouchUpInside];
//设置保持按钮的高亮状态(放在一个循环里面,强制按钮高亮)- (IBAction)onTouchup:(UIButton *)sender {　　[self performSelector:@selector(highlightButton:) withObject:sender afterDelay:0.0];}/*- (void)addMusicAction:(id)sender{    [self performSelector:@selector(highlightButton:) withObject:sender afterDelay:0.0];}*/
//设置按钮高亮- (void)highlightButton:(UIButton *)btn {      [btn setHighlighted:YES];}