输入时placeholder带弹起动画的TextField
仅需设置成为焦点后的属性即可
ZLPlaceHolderAnimationTextField *loginTextField = [[ZLPlaceHolderAnimationTextField alloc]initWithFrame:CGRectMake(20, 40, textFieldWidth, textFieldHeight)];
loginTextField.placeholder = @"手机号码";
loginTextField.aniPlaceHolderColor = [UIColor blueColor];
loginTextField.aniPlaceHolderfont = [UIFont systemFontOfSize:12];
也可以通过修改placeholderColor和placeholderFont来设置成为焦点之前的placeholder属性