ios textfield placeholder 放在右侧

_nameTF=[[UITextFieldalloc]initWithFrame:CGRectMake(ScreenWidth-165,14,150,14)];

_nameTF.placeholder=@"请输入申请人姓名";

UILabel* placeholderLabel = [_nameTFvalueForKey:@"_placeholderLabel"];

placeholderLabel.textAlignment=NSTextAlignmentRight;

_nameTF.textAlignment=NSTextAlignmentRight;