iOS基础-播放暂停按钮

[btn setImage:[UIImage imageWithName:@"paly"] forState:UIControlStateNormal];

[btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];

- (void)btnClick:(UIButton *)btn{
     if(btn.tag == -1){
      [btn setImage:[UIImage imageWithName:@"paly"] forState:UIControlStateNomal];
      NSLog(@"开始播放");
      btn.tag = 0;
      }else{
      [btn setImage:[UIImage imageWithName:@"pause"] forState:UIControlStateNomal];
      NSLog(@"暂停播放");
      btn.tag = -1;
      }
}