我在我的ASP.Net项目中创建了一个名为LitHoldModifications的类。这是代码:
[Serializable]
public class LitHoldModifications
{
private Boolean _changed;
private Hashtable _added;
private Hashtable _deleted;
public Boolean Changed
{
get { return _changed; }
set { _changed = value; }
}
public Hashtable Added
{
get { return _added; }
set { _added = value; }
}
public Hashtable Deleted
{
get { return _deleted; }
set { _deleted = value; }
}
public Hashtable Add(String item1, String item2)
{
Added = new Hashtable();
Added.Add(item1, item2);
return Added;
}
public Hashtable Delete(String item1, String item2)
{
Deleted = new Hashtable();
Deleted.Add(item1, item2);
return Deleted;
}
}
我遇到的问题是我需要能够将多个项目添加到此类的实例中。我必须这样做的代码是(在aspx页面中):
public LitHoldModifications AffectedEmployeeModifications
{
get
{
if (ViewState["AffectedEmployeeModifications"] != null)
return (LitHoldModifications)ViewState["AffectedEmployeeModifications"];
else
return null;
}
set
{
ViewState["AffectedEmployeeModifications"] = value;
}
}
protected void ProcessAffectedviaJavascript()
{
string[] employees = HiddenEmployeesPopup.Value.Split('|');
if (employees.Length>1) {
foreach (string s in employees)
{
if (s.Length > 1)
{
string Anumber = s.Split('@')[0];
string AName = s.Split('@')[1];
ListItem item = new ListItem();
item.Text = AName;
item.Value = Anumber;
lstSelEmployees.Items.Add(item);
//Clear values in temp hidden field:
HiddenEmployeesPopup.Value = "";
AffectedEmployeeModifications.Add(Anumber, AName);
AffectedEmployeeModifications.Changed = true;
}
}
}
当我运行我的代码并进入ProcessAffectedviaJavascript()时,字符串[]雇员填充了多个名称,但每次代码到达AffectedEmployeeModifications.Add ...行时,都会创建一个新的Hashtable并返回Add方法,因此已添加到AffectedEmployeeModifications的员工的任何早期字符串都将丢失。我能想到的唯一方法是更改Add方法以将AffectedEmployeeModifications作为参数并执行此操作:
public Hashtable Add(Hashtable lhm, String item1, String item2)
{
lhm.Add(item1, item2);
return lhm;
}
然后,在我的aspx.cs中:
AffectedEmployeeModifications = AffectedEmployeeModifications.Add(AffectedEmployeeModifications, Anumber, AName);
虽然这看起来并不是很好,而且我的OOP技能显然很缺乏。我该怎么做?
答案 0 :(得分:5)
您应该在类的构造函数中构造类所需的对象。您应该添加如下默认构造函数:
public LitHoldModifications()
{
Added = new Hashtable();
Deleted = new Hashtable();
}
然后您可以删除Add()和Delete()方法中的赋值,因为您可以在这些方法中假设这些成员变量已经有效。
我还建议您将添加/删除方法更改为返回void。如果您想要访问已添加/已删除的哈希表,则可以改为引用该属性。
var myLitInstance = new LitHoldModifications();
myLitInstance.Add("value1", "value2");
Hashtable tbl = myLitInstance.Added;