c#接口列表 [英] c# List of interfaces

问题描述

我必须做像画图的应用程序.我必须画线，矩形和椭圆形.我想使用STATE deisgn patern.我制作了Line，Rect和Ellipse和Interface IPaint类.


在班级主修中，我制作了IPaint油漆，而List< IPaint> list = new Line< IPaint>();然后通过3个按钮，我添加paint = new Line();或rect或ellipse()取决于单击的夹心按钮.但是当我使用list.Add(paint)时这无法正常工作.

当我添加第一个元素时可以，但是当我添加第二个元素时，第一个元素看起来像第二个.当我添加thirth元素时，请先添加，然后再添加el.具有像thitrh这样的价值.

我该怎么做对呢?

/////edit
是的，这只是帖子中的错字.在代码中是

I have to do application like Paint. I have to paint Line, Rectangule and Ellipse. I want to use STATE deisgn patern. I made class Line, Rect and Ellipse and Interface IPaint.


In class main I made IPaint paint, and List<IPaint> list= new Line<IPaint>(); Then by 3 buttons i add paint = new Line(); or rect or ellipse() depends on wich button are clicked. But when I`m use list.Add(paint) this not working correct.

When i add first element it`s OK, But when i add second element then first element look like second. When i`m add thirth element then first, and second el. have value like thitrh.

How can i do this right ?

/////edit
Yes it`s just a typo in post. In code is

List<IPaint> list = new List<IPaint>;

我现在在工作，我没有访问代码的权限.
但是完整的代码如下所示:

接口IPaint

Im in work now and i dont have acces to code.
But full code look like:

Interface IPaint

Interface IPaint
{
void Paint{PrintEvenArgs e}
Point BeginPoint{get;set;}
Point EndPoint(get;set)
}

Class Line，Rect和Ellipse外观相同:

Class Line, Rect and Ellipse look the same:

Class Line: IPaint{
public Begin/Endpoint {get;set;}
void Paint(PrintEventArgs e)
{
Pen p = new Pen(Color red,2)
e.drawLine(p,BeginPoint,EndPoint)
}
//in Rect and ellipse only change drawRectangle or DrawEllipse
}

在Form1中，我这样做:

In Form1 i do:

Class Main{
IPaint point;
List<IPaint> lista = new List<IPaint>();

 Void Main
 {


    Inicianization();
 }

  event MouseDown(Obiect Sender, MouseArgs e)
  {
     point.BeginPoint = e.location;

  }
  
  event mouseMove(...)
  {
    point.EndPoint = e.location;
    Invalidate();
  }

  event mouseup(..)
  {
    lista.Add(point);
  }

event Form1_Paint(Object Sender, PrintEventArgs e)

  If (!Point.BeginPoint.IsNull & !Point.EndPoint.IsnuLL)
  {
    point.Paint(e);
  }

  for (int i =0, i< lista.Count, i++)
  {
    lista[i].Paint(e);
  }

event button1_click(...)
{
point = new Line();
// button 2 - point = New Rectangle or ellipse button 3
}
}

问题在添加到列表中.当我添加第一个元素的秒数为(2,2)m秒(3,3)时，则首先将值更改为列表中第二个元素，当我添加第三个元素的点数为(5,6)时，则第一个元素和第二个元素的更改值到第三个元素和列表如下:

清单[0]-起点-5
-端点-6
清单[1]-起点-5
-端点-6
清单[2]-起点-5
-端点-6


看来当我添加到列表对象点时，它是通过引用添加的.但是为什么呢?

Problem is in add to list. When i Add first element with point`s (2,2)m second (3,3) then first change value to second element on the list, when i add thirth with points (5,6) then first and secont element change value to thirth element and list look like:

list[0] - Begin point - 5
- EndPoint - 6
list[1] - Begin point - 5
- EndPoint - 6
list[2] - Begin point - 5
- EndPoint - 6


It is look like when i add to list object point, it is add by reference. But why ?

推荐答案

List<IPaint> list= new Line<IPaint>();

这里有一个错字;你应该写:

There is a typo here ; you should rather write :

List<IPaint> list = new List<IPaint>();

如果这只是您帖子中的错字(而不是您的实际代码中的错字)，那么您是否使三个类(Line，Rectangle，Ellipse)实现了IPaint?

If this is just a typo in your post (and not in your actual code), did you make your three classes (Line, Rectangle, Ellipse) implement IPaint ?

我在列表上始终添加相同的对象point，当我更改对象的值时，我又一次将其添加到列表中，但是相同的对象及其所有内容均通过引用提供.

我必须将MouseMove事件更改为:

Like I sad before, i add on list always the same Object point, when i change value of obiect i one more time add to list but the same obiect and its everthing is by reference.

I have to change in MouseMove event to:

if Line
point = New Line();
if rect;// 
point = New Rect();
else point = (New Ellipse();

point.EndPoint = e.location

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