Question

我有第三方DLL我想直观地修改。我想更改表单上可用的按钮外观。使用dotPeek我发现按钮名称，现在在表单加载事件处理程序中我想使用下面的行修改该按钮：

this.cancelBtn.Enabled = true;
this.cancelBtn.ForeColor = Color.Red;
this.cancelBtn.Font = new Font(this.cancelBtn.Font.FontFamily, this.cancelBtn.Font.Size, FontStyle.Bold, GraphicsUnit.Pixel);

我可以使用Mono.Cecil加载和修改该程序集，如下所示：

var assembly = AssemblyDefinition.ReadAssembly(source);
var module = assembly.MainModule;
var name = assembly.Name;

TypeDefinition type = assembly.MainModule.Types.First(t => t.FullName == "SimpleEditor.MainDialog");

MethodDefinition method = type.Methods.First(m => m.Name == "Main_Load");

ILProcessor procesor = method.Body.GetILProcessor();
var firstInstruction = procesor.Body.Instructions.First();

MethodInfo writeLineMethod = typeof (Debug).GetMethod("WriteLine", new Type[] {typeof (string)});
var writeLine = assembly.MainModule.Import(writeLineMethod);

var callWriteLine = procesor.Create(Mono.Cecil.Cil.OpCodes.Call, writeLine);

const string sentence = @"MONO.CECIL rocks!";
var insertSentence = procesor.Create(Mono.Cecil.Cil.OpCodes.Ldstr, sentence);

procesor.InsertBefore(firstInstruction, insertSentence);
procesor.InsertAfter(insertSentence, callWriteLine);

assembly.Write(source);

但我现在所能做的就是在Main_Load方法的开头添加Debug.WriteLine("MONO.CECIL rocks!")。

我想从以下方法更改该方法：

private void Main_Load(object sender, EventArgs e)
{
    SetupEverything();
}

为：

private void Main_Load(object sender, EventArgs e)
{
    this.cancelBtn.Enabled = true;
    this.cancelBtn.ForeColor = Color.Red;
    this.cancelBtn.Font = new Font(this.cancelBtn.Font.FontFamily, this.cancelBtn.Font.Size, FontStyle.Bold, GraphicsUnit.Pixel);

    SetupEverything();
}

我怎么能用Mono.Cecil做到这一点？我无法在线找到有关Mono.Cecil的更多信息，因此我不知道如何获取属性（控件）并更改其属性（例如Font）。

Answer 1

这应该有效

.lock()

IL static void ChangeButtonProperties() { // Load the assembly and the main module string assemblyPath = $"{Environment.CurrentDirectory}\\ClassLibrary1.dll"; var mainModule = AssemblyDefinition.ReadAssembly(assemblyPath).MainModule; // Get the method to change TypeDefinition type = mainModule.Types.First(t => t.Name == "Test"); MethodDefinition method = type.Methods.Single(m => m.Name == "Main_Load"); // Get the instance field of the button FieldDefinition btnField = type.Fields.Single(f => f.Name == "_btn"); var controlType = mainModule.Import(typeof(Control)); // Import relevant types var colorType = mainModule.Import(typeof(Color)); var fontType = mainModule.Import(typeof(Font)); var fonFamilyType = mainModule.Import(typeof(FontFamily)); // Get the setters of the requested properties MethodDefinition setEnabled = controlType.Resolve().Methods.Single(m => m.Name == "set_Enabled"); MethodReference setEnabledRef = mainModule.Import(setEnabled); MethodDefinition setForeColor = controlType.Resolve().Methods.Single(m => m.Name == "set_ForeColor"); MethodReference setForeColorRef = mainModule.Import(setForeColor); MethodDefinition setFont = controlType.Resolve().Methods.Single(m => m.Name == "set_Font"); MethodReference setFontRef = mainModule.Import(setFont); // Get the Font constructor. Maybe you can think of a better way MethodDefinition fontCtor = fontType.Resolve().Methods.Single( m => m.IsConstructor && m.Parameters.Count == 4 && m.Parameters[0].ParameterType.Name == "FontFamily"); MethodReference fontCtorRef = mainModule.Import(fontCtor); // Get the getters of the requested properties var getRedColor = colorType.Resolve().Methods.Single(m => m.Name == "get_Red"); MethodReference getRedColorRef = mainModule.Import(getRedColor); var getFont = controlType.Resolve().Methods.Single(m => m.Name == "get_Font"); MethodReference getFontRef = mainModule.Import(getFont); var getFontSize = fontType.Resolve().Methods.Single(m => m.Name == "get_Size"); MethodReference getFontSizeRef = mainModule.Import(getFontSize); var getFontFamily = fontType.Resolve().Methods.Single(m => m.Name == "get_FontFamily"); MethodReference getFontFamilyRef = mainModule.Import(getFontFamily); // I clear just for the example. // You can keep the instructions and enter the new one before\after method.Body.Instructions.Clear(); ILProcessor processor = method.Body.GetILProcessor(); LoadInstanceField(processor, btnField); // Set Enabled to true processor.Emit(OpCodes.Ldc_I4_1); processor.Emit(OpCodes.Callvirt, setEnabledRef); LoadInstanceField(processor, btnField); // Set color to red processor.Emit(OpCodes.Call, getRedColorRef); // no need callvirt here because is static processor.Emit(OpCodes.Callvirt, setForeColorRef); LoadInstanceField(processor, btnField); LoadInstanceField(processor, btnField); // Get all parameters to create new Font object processor.Emit(OpCodes.Callvirt, getFontRef); processor.Emit(OpCodes.Callvirt, getFontFamilyRef); LoadInstanceField(processor, btnField); processor.Emit(OpCodes.Callvirt, getFontRef); processor.Emit(OpCodes.Callvirt, getFontSizeRef); processor.Emit(OpCodes.Ldc_I4_1); // Load 1. It's the enum value of FontStyle.Bold processor.Emit(OpCodes.Ldc_I4_2); // Load 2. It's the enum value of GraphicsUnit.Pixel // Call Font constructor processor.Emit(OpCodes.Newobj, fontCtorRef); // Set the font processor.Emit(OpCodes.Callvirt, setFontRef); processor.Emit(OpCodes.Ret); // Return from the method method.Body.OptimizeMacros(); mainModule.Write(assemblyPath + ".new.dll"); // Save the new dll } static void LoadInstanceField(ILProcessor processor, FieldDefinition field) { processor.Emit(OpCodes.Ldarg_0); // Load this processor.Emit(OpCodes.Ldfld, field); // Load button field }之前：

Main_Load

之后：

IL_0000: nop
IL_0001: ret

Mono.Cecil - 改变私有财产

1 个答案: