C#内存泄漏的四个常见场景及其解决办法

// 示例：用using语句释放文件流资源  
using (filestream filestream = new filestream("test.txt", filemode.open))  
{ 
    byte[] buffer = new byte[1024];  
    int bytesread = filestream.read(buffer, 0, buffer.length);  
    console.writeline($"读取了 {bytesread} 字节");  
} // 离开using块，filestream自动调用dispose()  

// 示例：wpf窗口关闭时取消事件订阅  
public class mywindow : window  
{ 
    public mywindow()  
    { 
        // 订阅事件  
        someservice.ondatareceived += handledatareceived;  
    }  

    private void handledatareceived(object sender, eventargs e)  
    { 
        // 处理数据  
    }  

    protected override void onclosed(eventargs e)  
    { 
        // 取消订阅  
        someservice.ondatareceived -= handledatareceived;  
        base.onclosed(e);  
    }  
}  

// 示例：用concurrentdictionary并设置最大容量  
public class cachemanager  
{ 
    private static concurrentdictionary<int, string> _cache = new concurrentdictionary<int, string>();  
    private const int maxcapacity = 1000;  

    public static void add(int key, string value)  
    { 
        _cache.tryadd(key, value);  

        // 如果超过容量，移除最旧的项  
        if (_cache.count > maxcapacity)  
        { 
            var oldestkey = _cache.keys.orderby(k => k).first();  
            _cache.tryremove(oldestkey, out _);  
        }  
    }  
}  

// 故意制造内存泄漏（示例）  
public class memoryleakexample  
{ 
    private static list<byte[]> _leaklist = new list<byte[]>();  

    public void leakmemory()  
    { 
        for (int i = 0; i < 100000; i++)  
        { 
            _leaklist.add(new byte[1024 * 1024]); // 每次分配1mb内存  
        }  
    }  
}  

// 示例：自定义字符串对象池  
public class stringobjectpool : objectpool<string>  
{ 
    public stringobjectpool(int maxsize) : base(() => "default", maxsize) {}  
}  

// 使用对象池  
var pool = new stringobjectpool(100);  
string str = pool.get();  
// 使用完毕后归还  
pool.return(str);