public class MyClass {
private static MyClass heldInstance;
public MyClass() {
heldInstance = this;
}
}
假设MyClass的一个实例没有以任何其他方式生根,那么这里的私有静态引用是否会阻止它被垃圾收集？
解决方法
您发布的课程不会被垃圾收集.你可以通过给它一个带控制台输出的终结器来测试它：
public class MyClass
{
private static MyClass heldInstance;
public MyClass()
{
heldInstance = this;
}
~MyClass()
{
Console.WriteLine("Finalizer called");
}
}
class Program
{
static void Main(string[] args)
{
var x = new MyClass(); // object created
x = null; // object may be eliglible for garbage collection now
// theoretically,a GC could happen here,but probably not,with this little memory used
System.Threading.Thread.Sleep(5000);
// so we force a GC. Now all eligible objects will definitely be collected
GC.Collect(2,GCCollectionMode.Forced);
//however their finalizers will execute in a separate thread,so we wait for them to finish
GC.WaitForPendingFinalizers();
System.Threading.Thread.Sleep(5000);
Console.WriteLine("END");
}
}
输出将是：
END Finalizer called
这意味着该类仅在应用程序的最终拆解时收集,而不是在常规垃圾收集期间收集.
如果您创建此类的多个实例,如下所示：
var x = new MyClass(); x = new MyClass(); x = new MyClass(); x = new MyClass();
然后除最近的一个之外的所有将被垃圾收集.
你会得到的
Finalizer called Finalizer called Finalizer called END Finalizer called
