1.修改UITextField的placeholder的大小颜色有2种方法
1.1 KVC
TextField.placeholder = rightText;
[TextField setValue:KColorFontGray forKeyPath:@"_placeholderLabel.textColor"];
[TextField setValue:[UIFont boldSystemFontOfSize:14.0f] forKeyPath:@"_placeholderLabel.font"];```
#####1.2 attributedPlaceholder(iOS6以后)
NSMutableAttributedString *placeholder = [[NSMutableAttributedString alloc]initWithString:rightText
attributes:@{NSForegroundColorAttributeName:KColorFontGray,
NSFontAttributeName:[UIFont boldSystemFontOfSize:14.0f]}];
rightTextField.attributedPlaceholder = placeholder;```
但是这样做存在一个问题，设置的字号过小之后，placeholder会不再垂直居中，如下图效果：
问题.png
2.解决上述垂直居中问题
在attributes中再添加一组属性，即可解决
NSMutableParagraphStyle *style = [rightTextField.defaultTextAttributes[NSParagraphStyleAttributeName] mutableCopy];
style.minimumLineHeight = rightTextField.font.lineHeight - (rightTextField.font.lineHeight - [UIFont systemFontOfSize:14.0f].lineHeight) / 2.0;
TextField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:rightText
attributes:@{NSForegroundColorAttributeName:KColorFontGray,
NSFontAttributeName : [UIFont systemFontOfSize:14.0f],
NSParagraphStyleAttributeName : style}];```