锁定语句未按预期工作

我在下面有一些带有 2 个锁定语句的示例源代码。在我的测试运行期间，我单击"r1RefreshButton"将showReport1方法放入永久循环中。然后我单击"r2RefereshButton"以检查锁定是否按预期执行。

我发现showReport2上的锁并没有真正锁定。我错过了什么吗？

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# 锁定事件中找到了类似的主题