锁定语句未按预期工作

Question

我有一些示例源代码,下面有2个锁定语句.在我的测试运行期间,我点击'r1RefreshButton'将showReport1方法放入一个永久循环中.然后我点击'r2RefereshButton'来检查锁是否按预期进行.

我发现showReport2上的锁并没有真正锁定.我错过了什么？

public partial class TestReportsForm : Form
{
    private static readonly Object thisLock = new Object();

    public TestReportsForm() { InitializeComponent(); }

    private void showReport1()
    {
        lock (thisLock)
        {
            r1RefreshButton.Enabled = false;
            try
            {
                // while loop is used to simulate long process
                while (true)
                {
                    Application.DoEvents();
                }
            }
            catch (Exception ex)
            {
                String errorMessage = "Error encountered\n\n" +
                       "Error details: \n" +
                       ex.Message;
                MessageBox.Show(this, errorMessage, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                r1RefreshButton.Enabled = true;
            }
        }
    }

    private void r1RefreshButton_Click(object sender, EventArgs e)
    {
        showReport1();
    }

    private void showReport2()
    {
        lock (thisLock)
        {
            r2RefreshButton.Enabled = false;
            try
            {
                Application.DoEvents();
                // long process here
            }
            catch (Exception ex)
            {
                String errorMessage = "Error encountered\n\n" +
                       "Error details: \n" +
                       ex.Message;
                MessageBox.Show(this, errorMessage, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                r2RefreshButton.Enabled = true;
            }
        }
    }

    private void r2RefreshButton_Click(object sender, EventArgs e)
    {
        showReport2();
    }
}    

编辑:我从C#Locking from events中找到了类似的主题

Answer 1

这两个函数都在同一个线程上运行.锁保持在线程级别.

因此,在GUI线程上运行的所有代码都"拥有"锁.

在这里阅读更多内容:http://msdn.microsoft.com/en-us/library/c5kehkcz.aspx