[textField setValue: [UIFont fontWithName: @“天线”尺寸:14),forKeyPath: @”_placeholderLabel.font ");//修改大小
[textField setValue:[用户界面颜色redColor] forKeyPath: @ " _placeholderLabel.textColor "]//修改颜色
[textField setValue: [UIFont fontWithName: @“天线”尺寸:14),forKeyPath: @”_placeholderLabel.font ");//修改大小
[textField setValue:[用户界面颜色redColor] forKeyPath: @ " _placeholderLabel.textColor "]//修改颜色