稍作总结:

searchBar show code
默认样式
barTintColor .searchBar.barTintColor = [UIColor orangeColor]
backgroundImage .backgroundImage = [[UIImage alloc] init]; 变为透明背景
backgroundColor(单独不起作用) searchBar.backgroundImage = [[UIImage alloc] init];searchBar.backgroundColor = [UIColor whiteColor];
内置的textFeild,可用kvc设置 20170524586915.png UITextField *tf = [searchBar valueForKey:@”_searchField”]; tf.backgroundColor = [UIColor redColor]
隐藏边缘的黑线 sb.layer.borderWidth = 1; sb.layer.borderColor = [[UIColor whiteColor] CGColor];