C#-公共语言运行时检测到无效程序-ILGenerator
作者:互联网
基本上,我试图将字节数组中的数据反序列化为对象.我正在尝试使用UTF8编码的GetString方法来读取字符串.这是我的代码的一部分:
var mm = new DynamicMethod("get_value", typeof(object)
, new Type[] { typeof(byte[]), typeof(int), typeof(int), typeof(int) });
var utf8 = Encoding.GetEncoding("utf-8"); //l.GetValue(null, null).GetType().GetMethod("GetString");
var getstring = utf8.GetType().GetMethod("GetString", new Type[] { typeof(byte[]), typeof(int), typeof(int) });
// var getString = Encoding.UTF8.GetType().GetMethod("GetString", new Type[] { typeof(byte[]), typeof(int), typeof(int) });
var h = new EmitHelper(mm.GetILGenerator());
var defaultCase = h.ILGenerator.DefineLabel();
var lbs = new Label[] { h.DefineLabel(),h.DefineLabel()};
var getInt32Method = typeof(BitConverter).GetMethod("ToInt32", new Type[] { typeof(byte[]), typeof(int) });
//Arg0 = Byte [] , Arg1 = type, Arg2 = size, Arg3 = offset
h
.ldarg_1
.@switch(lbs)
.MarkLabel(defaultCase)
.ldnull
.ret();
h
.MarkLabel(lbs[0])
.ldarg_0
.ldarg_3
.call(getInt32Method)
.box(typeof(int))
.ret();
//THis is the function that is causing problem; If i remove this function works;
h
.MarkLabel(lbs[1])
.ldarg_0 //Load array
.ldarg_3 //Load Offset (index)
.ldarg_2 //Load Size (count)
.callvirt(getstring)
.boxIfValueType(typeof(string))
.ret();
return (GetValueDelegate)mm.CreateDelegate(typeof(GetValueDelegate));
我在此代码之外检查了“ getstring”的方法签名,并且可以正常工作.我尝试删除“ .boxIfAny”,还尝试使用“通话”而不是“ callvirt”.据我了解,“ callvirt”是适用于这种情况的实例方法.有任何想法吗?
解决方法:
调用GetString方法需要一个实例.
我简化了您的代码并将其设置为SSCCE:
using System;
using System.Reflection.Emit;
using System.Text;
class GetStringDemo {
public static DynamicMethod GetStringForEncoding(Encoding encoding) {
var getstringMethod = encoding.GetType().GetMethod("GetString",
new Type[] { typeof(byte[]) });
var getStringCreator = new DynamicMethod("foo", typeof(string),
new Type[] { typeof(byte[]), encoding.GetType() }, typeof(void));
ILGenerator gen = getStringCreator.GetILGenerator();
gen.Emit(OpCodes.Ldarg_1); // this is the instance for callvirt
gen.Emit(OpCodes.Ldarg_0);
gen.Emit(OpCodes.Callvirt, getstringMethod);
gen.Emit(OpCodes.Box, typeof(string));
gen.Emit(OpCodes.Ret);
return getStringCreator;
}
public static void Main() {
var utf8 = Encoding.GetEncoding("utf-8");
var method = GetStringForEncoding(utf8);
Console.WriteLine(method.Invoke(null, new object[2] {
new byte[] { 0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20,
0x32, 0x30, 0x31, 0x34, 0x21 },
utf8 } ));
}
}
// Output:
Hello 2014!
在调用h.ldarg_0 //加载数组之前,请加载实际的调用目标.如果没有它,您确实会得到mscorlib抛出的System.InvalidProgramException.
标签:reflection-emit,ilgenerator,bltoolkit,ilasm,c 来源: https://codeday.me/bug/20191122/2058648.html