关闭后IWindowsFormsEditorService延迟

Question

我需要将一个自定义属性值编辑器集成到PropertyGrid控件中。代码如下

internal class VariableTypeEditor : UITypeEditor
{
    public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
    {
        return UITypeEditorEditStyle.DropDown;
    }

    public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
    {
        IWindowsFormsEditorService service = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;

        Type type = context.GetType();
        PropertyInfo property = type.GetProperty("OwnerGrid");

        IPlugIn plug = context.Instance as IPlugIn;

        if (service != null && property != null
                            && plug != null)
        {
            PropertyGrid owner = property.GetValue(context) as PropertyGrid;

            if (owner != null)
            {
                Collection<VariableWrapper> variables = owner.Tag as Collection<VariableWrapper>;

                if (variables != null)
                {
                    VariableEditorForm editor = new VariableEditorForm();
                    editor.Value = plug.VariableName;
                    editor.Variables = variables.Select(o => o.Variable).Where(o => o.ValueType == plug.VariableType).ToArray();
                    editor.TopLevel = false;
                    editor.FormClosed += new FormClosedEventHandler((sender, args) =>
                    {
                        service.CloseDropDown();
                    });

                    service.DropDownControl(editor);
                    value = editor.Value;
                }
            }
        }

        return value;
    }
}

我希望它以这种方式工作：

• 更改属性的值用户打开带有VariableEditorForm的DropDown（使用PropertyGrid）
• 用户选择VariableEditorForm中列出的值之一，之后VariableEditorForm会自动关闭

它现在有效。但由于某种原因，在EditValue方法返回其值之前需要2-3秒。

为什么service.DropDownControl(editor)在关闭后不会立即返回？

Answer 1

我设法找到了解决方案。我不喜欢，但它的工作原理。代码如下。

            public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
            {
                IWindowsFormsEditorService service = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;

                Type type = context.GetType();
                PropertyInfo property = type.GetProperty("OwnerGrid");

                IPlugIn plug = context.Instance as IPlugIn;

                if (service != null && property != null
                                    && plug != null)
                {
                    PropertyGrid owner = property.GetValue(context) as PropertyGrid;

                    if (owner != null)
                    {
                        Collection<VariableWrapper> variables = owner.Tag as Collection<VariableWrapper>;

                        if (variables != null)
                        {
                            VariableEditorForm editor = new VariableEditorForm();
                            editor.Value = plug.VariableName;
                            editor.Variables = variables.Select(o => o.Variable).Where(o => o.ValueType == plug.VariableType).ToArray();
                            editor.TopLevel = false;
                            editor.FormClosed += new FormClosedEventHandler((sender, args) =>
                            {
                                // disable main form rendering
                                User32.PostMessage(Process.GetCurrentProcess().MainWindowHandle, Messages.WM_DISABLE_RENDER, IntPtr.Zero, IntPtr.Zero);
                                service.CloseDropDown();
                            });

                            service.DropDownControl(editor);

                            // enable main form rendering
                            User32.PostMessage(Process.GetCurrentProcess().MainWindowHandle, Messages.WM_ENABLE_RENDER, IntPtr.Zero, IntPtr.Zero);
                            value = editor.Value;
                            editor.Dispose();
                        }
                    }
                }

                return value;
            }

事实上，我的主窗体上有一个面板，它使用定时器来不断渲染自己。我注意到每次禁用该计时器时我的问题都会消失。所以没有更好的解决方案我决定将消息发布到我的主窗体以启用/禁用提到的计时器。

如果有人能为我的问题提供适当的解决方案，我将不胜感激。