用户定义类型选择正确的重载operator+的一般性处理例如我们在赋值语句中经常使用 a+=1 ; b-=2; c*=3; d/=3; 如果x和y是用户定义的类型, 就不能确保这样。
代码如下 :
代码如下 :
1
public class Saver : IDisposable
2
{
3
// Fields
4
private TextBox m_textBox;
5![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
6
private int m_start, m_end;
7![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
8
/// <summary>
9
/// Initializes a new instance of the Saver class by associating it with a TextBoxBase derived object. </summary>
10
/// <param name="textBox">
11
/// The TextBoxBase object for which the selection is being saved. </param>
12
/// <remarks>
13
/// This constructor saves the textbox's start and end position of the selection inside private fields. </remarks>
14
/// <seealso cref="System.Windows.Forms.TextBoxBase" />
15
public Saver(TextBox textBox)
16
{
17
m_textBox = textBox;
18
}
19![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
20
public static Saver operator +(Saver saver, int pos)
21
{
22
return new Saver(saver.m_textBox, saver.m_start + pos, saver.m_end + pos);
23
}
24![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
25
public void MoveBy(int start, int end)
26
{
27
m_start += start;
28
m_end += end;
29![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
30
Debug.Assert(m_start <= m_end);
31
}
32
}
33![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
2
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
3
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
4
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
5
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
6
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
7
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
8
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
9
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
10
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
11
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
12
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
13
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
14
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
15
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
16
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
17
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
18
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
19
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
20
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
21
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
22
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
23
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
24
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
25
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
26
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
27
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
28
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
29
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
30
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
31
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
32
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
33
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)