iOS改变searchBar搜索栏placeholder的字体颜色

如题所示，就是一个小tip，百度了很久都没答案，就在stackoverflow上找到了答案，方法有如下几种：

1.iOS5+ oc版：

[[UILabelappearanceWhenContainedIn:[UISearchBarclass],nil]setTextColor:[UIColorredColor]];

2.取出searcher里的textfield，再进行修改：

//取出textfield

UITextField*searchField=[searchBar valueForKey:@"_searchField"];

//改变searcher的textcolor

searchField.textColor=[UIColor redColor];

//改变placeholder的颜色

[searchField setValue：[UIColorblueColor]forKeyPath:@"_placeholderLabel.textColor"];

3.swift版

var  textFieldInsideSearchBar=searchBar.valueForKey("searchField")as?UITextField

textFieldInsideSearchBar?.textColor=UIColor.whiteColor()   

var  textFieldInsideSearchBarLabel=textFieldInsideSearchBar!.valueForKey("placeholderLabel")as?UILabel

textFieldInsideSearchBarLabel?.textColor=UIColor.whiteColor()

以上内容参考ios - UISearchBar change placeholder color - Stack Overflow