iOS textfield浅析

1. 修改placeholder字体、颜色等，其实textfield的placeholder是一个UILabel，只要取出它的label，就可以设置，这里介绍一种KVC的方式

textField.placeholder = @"username is in here!";  [textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];  [textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];