iOS6.0之后提供的attributedPlaceholder屬性
NSString*holderText =@"輸入餐廳名稱或者編號";
NSMutableAttributedString*placeholder = [[NSMutableAttributedStringalloc]initWithString:holderText];
[placeholderaddAttribute:NSForegroundColorAttributeName
value:[UIColorwhiteColor]
range:NSMakeRange(0, holderText.length)];
textFiled.attributedPlaceholder= placeholder;