了解Finalize & Dispose & Close

最新推荐文章于 2021-04-06 15:06:39 发布

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最新推荐文章于 2021-04-06 15:06:39 发布

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原文链接：http://www.cnblogs.com/zzq417/archive/2013/05/23/Finalize_Dispose.html

本文详细解释了Finalize与Dispose方法在资源释放方面的区别及使用场景。Dispose采用显式方式，通常由程序员直接调用，并负责托管和非托管资源的释放；而Finalize则为隐式，由垃圾回收器调用，主要负责非托管资源的释放。文章还通过示例代码展示了如何正确实现这两个方法。

Finalize& Dispose are all release resources, and their function should be the same.The difference between them is, Finalize is in implicit way, and dispose is inexplicit. Another difference is finalize will be called by GC, but dispose is being called by coder.So dispose should run GC.SuppressFinalize(), and don't forget to override finalize

Close:Official has no limit that 'close' just mean release resource. Usually, there are only one method, close or dispose which do release resource and in public.

Let's look a sample

 1 public class AuthorizeBackup : IDisposable
 2     {
 3         private bool _disposed = false;
 4         private System.IO.FileStream fs = new System.IO.FileStream("", System.IO.FileMode.Create);
 5         private Dictionary<string, string> dic = new Dictionary<string, string>();
 6 
 7         public void Dispose()
 8         {
 9             Dispose(true);
10             GC.SuppressFinalize(this);
11         }
12 
13         protected virtual void Dispose(bool disposing)
14         {
15             //允许多次调用
16             if (!_disposed)
17             {
18                 //主动调用时，也释放managed resource
19                 if (disposing)
20                 {
21                     
22                 }
23                 //释放unmanaged resource
24                 fs.Close();
25 
26                 _disposed = true;
27             }
28         }
29 
30         ~AuthorizeBackup()
31         {
32             Dispose(false);
33         }
34     }

View Code

Add a derive class

 1 public class RoleAuthorizeBuckup : AuthorizeBackup
 2     {
 3         private System.IO.BinaryWriter _write;
 4         private bool _disposed = false;
 5 
 6         protected override void Dispose(bool disposing)
 7         {
 8             if (!_disposed)
 9             {
10                 if (disposing)
11                 {
12                     
13                 }
14                 _write.Close();
15                 _disposed = true;
16                 base.Dispose(disposing);
17             }
18         }
19     }