相关疑难解决方法(0)

我从阅读MSDN文档中了解到,IDisposable接口的"主要"用途是清理非托管资源.

对我来说,"非托管"意味着数据库连接,套接字,窗口句柄等等.但是,我已经看到了Dispose()实现该方法以释放托管资源的代码,这对我来说似乎是多余的,因为垃圾收集器应该照顾那对你而言.

例如:

public class MyCollection : IDisposable
{
    private List<String> _theList = new List<String>();
    private Dictionary<String, Point> _theDict = new Dictionary<String, Point>();

    // Die, clear it up! (free unmanaged resources)
    public void Dispose()
    {
        _theList.clear();
        _theDict.clear();
        _theList = null;
        _theDict = null;
    }

我的问题是,这是否使得垃圾收集器可以使用的内存MyCollection比通常更快？

编辑:到目前为止,人们已经发布了一些使用IDisposable清理非托管资源(例如数据库连接和位图)的好例子.但是假设_theList在上面的代码中包含了一百万个字符串,并且你想现在释放那个内存,而不是等待垃圾收集器.上面的代码会实现吗？

在方法中将自定义对象设置为null(Nothing在VB.NET中)是否有意义Dispose()？这可以防止内存泄漏或无用吗？!

让我们考虑两个例子:

public class Foo : IDisposable
{
    private Bar bar; // standard custom .NET object

    public Foo(Bar bar) {
        this.bar = bar;
    }
    public void Dispose() {
        bar = null; // any sense?
    }
}

public class Foo : RichTextBox
{
    // this could be also: GDI+, TCP socket, SQl Connection, other "heavy" object
    private Bitmap backImage; 

    public Foo(Bitmap backImage) {
        this.backImage = backImage;
    }

    protected override void Dispose(bool disposing) {
        if (disposing) …

我有一个像下面这样的功能:

Public Function testFunction(ByVal input_string As String) As String

    Dim s As New StringBuilder()
    Dim c As Char
    For i As Integer = 0 To input_string.Length - 1
        c = input_string.Chars(i)
        s.Append(c)
    Next
    Return s.ToString

End Function

但我想知道是否最好明确销毁任何对象,如下所示:

    Public Function testFunction(ByVal input_string As String) As String

    Dim s As New StringBuilder()
    Dim c As Char
    For i As Integer = 0 To input_string.Length - 1
        c = input_string.Chars(i)
        s.Append(c)
    Next

    Dim t As String = s.ToString
    s = Nothing

    Return …