将C＃语句体lambda转换为VB [英] Convert C# statement body lambda to VB

问题描述

看起来VS8中的VB不支持/转换带有语句体的lambda表达式。我在C＃应用程序中使用它们，但现在必须将其转换为VB。

It appears that VB in VS8 doesn't support/convert lambda expressions with a statement body. I'm using them in my C# application, but now must convert it to VB.

我正在动态创建一大堆控件，我想要在飞行中给他们事件处理程序。这样就可以从数据库中构建一个动态的用户界面。在下面的代码中，我将创建一个表单和一个复选框，使复选框控制窗体的可见性，在窗体中添加几个方法处理程序，然后将新创建的复选框添加到一个预先存在的窗体/面板/ etc中。例如，处理程序会影响复选框：

I'm creating a whole bunch of controls dynamically, and I want to be able to give them event handlers on the fly. This is so I can build a dynamic user interface from a database. In the following code I'll create a form and a checkbox, make the checkbox control the form's visibility, add a few method handlers to the form, and then add the newly created checkbox to a pre-existing form/panel/etc. Handlers for the form, for instance, affect the checkbox:

  // Inside some loop creating a lot of these forms and matching checkboxes
      Form frmTemp = frmTestPanels[i];  // New form in array
      CheckBox chkSelectPanel;          // New checkbox that selects this panel
      chkSelectPanel = new CheckBox();
      chkSelectPanel.Text = SomeName;   // Give checkbox a label
      chkSelectPanel.Click += (ss, ee) =>  // When clicked
      {
          label1.Text = SomeName;       // Update a label
          if (chkSelectPanel.Checked)   // Show or hide the form
          {
              frmTemp.Show();
          }
          else
          {
              frmTemp.Hide();
          }
      };

      frmTemp.VisibleChanged += (ss, ee) =>  // When form visibility changes
      {
          chkSelectPanel.Checked = frmTemp.Visible;  // Reflect change to checkbox
          ConfigurationFileChanged = true;   // Update config file later
      };

      frmTemp.FormClosing += (ss, ee) =>     // When the form closes
      {   // We're only pretending to close the form - it'll sit around until needed
          chkSelectPanel.Checked = false;    // Update the checkbox
          frmTemp.Hide();                    // Hide the form
          ee.Cancel = true;                  // Cancel the close
      };

      flpSelectGroup.Controls.Add(chkSelectPanel); // Add checkbox to flow layout panel
  // End of loop creating a bunch of these matching forms/checkboxes

当然，我得到转换错误，VB不支持匿名方法/ lambda表达式与语句正文

Of course, I'm getting the conversion error, "VB does not support anonymous methods/lambda expressions with a statement body"

我真的很喜欢能够在飞行中创建所有内容，然后让对象处理自己 - 我不需要添加任何特殊的功能来确定哪个窗体提供关闭事件，以便它可以搜索正确的复选框并更新复选框 - 它Just Works（TM）。

I really liked the ability to create everything on the fly, and then let the objects handle themselves - I don't need to add any special functions that figure out which form is giving the close event so it can search for the right checkbox and update the checkbox - It Just Works (TM).

不幸的是，它需要转换为VB。

Unfortunately it needs to be converted to VB.

• 将lambda /匿名语句体转换为可以在VB中工作的东西，最好的方式是什么？特别是当需要创建许多语句的时候，特别是当需要创建许多语句的时候？

-Adam

推荐答案

等待最接近的.NET 4版本，它将在VB中支持这样的事情。没有看到其他选择。

Wait for the nearest release of .NET 4, it will support things like this in VB. Don't see other alternative.

丑陋的选择是：

1. 这个工作，但是你可以在一个函数中使用一个语句。

1. This work, but you can use a single statement in a function.

AddHandler Me.Click, Function(o, e) MessageBox.Show("text")

创建一些常规的Sub Foo

Create some regular Sub Foo

Public Sub Foo(ByVal o As Object, ByVal e As EventArgs)
     MessageBox.Show("text")
End Sub

并使用 AddHandler 将其绑定到一个事件

and use AddHandler to bind it to an event

AddHandler Me.Click, AddressOf Foo

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