- textField.placeholder = @"username is in here!";
- [textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
- [textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];
ios修改textField的placeholder的字体颜色和大小
原文：http://www.cnblogs.com/it-k-50/p/5209426.html
