Question

我正在尝试从文本文件中读取和编译代码。我已经完成了一些部分，但在尝试向窗体添加控件时感到困难。请指导我。我附上代码。

Public Class Form1

    Sub Execute()

        ' Creates object of the compiler
        Dim objCodeCompiler As System.CodeDom.Compiler.ICodeCompiler = New VBCodeProvider().CreateCompiler

        'References/Parameters.
        Dim objCompilerParameters As New System.CodeDom.Compiler.CompilerParameters()

        objCompilerParameters.ReferencedAssemblies.Add("System.dll")
        objCompilerParameters.ReferencedAssemblies.Add("System.Windows.Forms.dll")
        objCompilerParameters.ReferencedAssemblies.Add("Microsoft.VisualBasic.dll")


        'Compiles in memory.
        objCompilerParameters.GenerateInMemory = True

        'Runs the source code.
        'You can use resources, textbox's or even the settings, up to you! :D
        'Dim strCode As String = TextBox1.Text

        'Compiler Results
        'Dim objCompileResults As System.CodeDom.Compiler.CompilerResults = objCodeCompiler.CompileAssemblyFromSource(objCompilerParameters, strCode)

        Dim objCompileResults As System.CodeDom.Compiler.CompilerResults = objCodeCompiler.CompileAssemblyFromFile(objCompilerParameters, "H:\VB project\LE21 - CodeDom - Run code from Textbox\LE21 - CodeDom - Run code from Textbox\LE21 - CodeDom - Run code from Textbox\file.txt")

        'If an Error occurs
        If objCompileResults.Errors.HasErrors Then
            MsgBox("Error: Line>" & objCompileResults.Errors(0).Line.ToString & ", " & objCompileResults.Errors(0).ErrorText)
            Exit Sub
        End If

        'Creates assembly
        Dim objAssembly As System.Reflection.Assembly = objCompileResults.CompiledAssembly

        Dim objTheClass As Object = objAssembly.CreateInstance("MainClass")
        If objTheClass Is Nothing Then
            MsgBox("Can't load class...")
            Exit Sub
        End If

        'Trys to excute
        Try
            objTheClass.GetType.InvokeMember("ExecuteCode",
                System.Reflection.BindingFlags.InvokeMethod, Nothing, objTheClass, Nothing)
        Catch ex As Exception
            MsgBox("Error:" & ex.Message)
        End Try

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        'Runs the source code from textbox1.
        Execute()

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged


    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        Dim p As New Form2
        p.Text = "hahahahah"
        p.Show()


    End Sub
End Class

Answer 1

＆＃34;类型Form2未定义＆＃34;

那是因为你还没有定义它。您可能正在动态加载和编译包含确定它的代码的某个文件。但编译器无法在编译时知道。作为一个静态类型系统，编译器需要知道编译代码时所使用的所有类型。

如果您从文件动态加载类定义，则还需要动态调用这些类定义。这会涉及很多reflection和CodeDOM以及诸如此类的东西。它不会很漂亮，并且它肯定不会进行编译时类型检查。（并且它将非常＆＃34;字符串输入＆＃34;在某种意义上，您不会创建Form2的实例，而是要从反射中请求创建实例"Form2"并且希望得到最好的。）所以你想要为诸如不存在的类之类的东西进行大量的错误处理。

从文本文件中动态读取/编译vb.net代码

1 个答案: