[英]C# Private Setter with Logic
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Crystal_Message
{
class Person
{
private string firstName="";
private string lastName= "";
private string phone="";
public Person(string firstName, string lastName, string phone)
{
this.FirstName = firstName;
this.LastName = lastName;
this.PhoneNumber = phone;
}
public string FirstName
{
get { return firstName; }
set
{
if (string.IsNullOrWhiteSpace(this.firstName)){
throw new ArgumentNullException("Must Include First Name");
}
this.firstName = value;
}
}
public string LastName
{
get { return lastName; }
set
{
if (string.IsNullOrWhiteSpace(lastName)){
throw new ArgumentNullException("Must Include Last Name");
}
this.lastName = value;
}
}
public string PhoneNumber
{
get { return phone; }
set
{
if (string.IsNullOrWhiteSpace(phone)){
throw new ArgumentNullException("Must Include Phone Number");
}
this.phone = value;
}
}
public override string ToString()
{
return "First Name: " + this.FirstName + " " + " Last Name: " + this.LastName + " Phone Number: " + this.PhoneNumber;
}
}
}
我有一個簡單的人類,它包含名字,姓氏和電子郵件。 它對我有用,並且不會被細分。 我正在構建一個小型應用程序,並且該人員類是合適的。
我唯一的問題是,如何使用內部邏輯實現私有設置器,以確保該值不為null或為空?
您可以對屬性設置器使用private修飾符:
public string FirstName
{
get { return firstName; }
private set
{
// Here you must check if value is not null or empty, not the field
if (string.IsNullOrWhiteSpace(value)){
throw new ArgumentNullException("Must Include First Name");
}
this.firstName = value;
}
}
在這種情況下,只能從同一類訪問屬性的設置器。
只將二傳手設為私人。 另外,您還有一個問題:
string.IsNullOrWhiteSpace(lastName)
將讀取現有屬性值。 您應該改為檢查新提供的value
:
string.IsNullOrWhiteSpace(value)
最終代碼:
public string LastName
{
get { return lastName; }
private set
{
if (string.IsNullOrWhiteSpace(value)) {
throw new ArgumentNullException("Must Include Last Name");
}
lastName = value;
}
}
有兩種方法:
首先,您可以擺脫set
而您的類可以對基礎值進行操作:
public string FirstName
{
get { return firstName; }
}
}
// Then in your code:
this.firstName = "whatever"; // the local variable
或者,您可以將設置器的范圍設置為private
:
public string FirstName
{
get { return firstName; }
private set
{
if (string.IsNullOrWhiteSpace(this.firstName)){
throw new ArgumentNullException("Must Include First Name");
}
this.firstName = value;
}
}
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