c# - FieldBuilder - Ho do you set the default value? -


i'm using typebuilder create types @ runtime, can't seem figure out how set default value of field.

for example, wanted create following layout @ runtime, using typebuilder, how set default value of 'm_number' (to 64)?

    public class dynamictype1 {     private int m_number = 64;      public int number     {         { return m_number; }         set { m_number = value; }     } }

here code use create property, ... how set field have value of 'defaultvalue'

void addproperty(string name, type type, object defaultvalue)     {         // add private field of type          fieldbuilder fieldbuilder = m_typebuilder.definefield("m_" + name.tolower(), type, fieldattributes.private);          // define property gets , sets private field. last argument of defineproperty null, because          // property has no parameters. (if don't specify null, must specify array of type objects. parameterless property,          // use built-in array no elements: type.emptytypes)         propertybuilder propertybuilder = m_typebuilder.defineproperty(name, propertyattributes.hasdefault, type, null);          // property "set" , property "get" methods require special set of attributes.         methodattributes getsetattr = methodattributes.public | methodattributes.specialname | methodattributes.hidebysig;          // define "get" accessor method. method returns value , has no arguments. (note null           // used instead of types.emptytypes)         methodbuilder getaccessormethodbuilder = m_typebuilder.definemethod("get_" + name, getsetattr, type, type.emptytypes);          // instance property, argument 0 instance. load instance, load private          //field , return, leaving field value on stack.         ilgenerator numbergetil = getaccessormethodbuilder.getilgenerator();         numbergetil.emit(opcodes.ldarg_0);         numbergetil.emit(opcodes.ldfld, fieldbuilder);         numbergetil.emit(opcodes.ret);          // define "set" accessor method number, has no return type , takes 1 argument of type t.         methodbuilder setaccessormethodbuilder = m_typebuilder.definemethod("set_" + name, getsetattr, null, new type[] { type });          // load instance , argument, store  argument in field.         ilgenerator numbersetil = setaccessormethodbuilder.getilgenerator();         numbersetil.emit(opcodes.ldarg_0);         numbersetil.emit(opcodes.ldarg_1);         numbersetil.emit(opcodes.stfld, fieldbuilder);         numbersetil.emit(opcodes.ret);          // last, map "get" , "set" accessor methods propertybuilder. property complete.          propertybuilder.setgetmethod(getaccessormethodbuilder);         propertybuilder.setsetmethod(setaccessormethodbuilder);     }

when in doubt, ask roslyn, in il mode :-) http://goo.gl/nebcep

the default field set in constructor(s) of object:

.method public hidebysig specialname rtspecialname      instance void .ctor () cil managed  {     // method begins @ rva 0x2061     // code size 15 (0xf)     .maxstack 8      il_0000: ldarg.0     il_0001: ldc.i4.s 64     il_0003: stfld int32 dynamictype1::m_number

note if there multiple constructors, seems constructors chain other constructors of same class don't set value, while constructors don't chain other constructor of same class set. see expanded example: http://goo.gl/8y90ku


Comments

Post a Comment

Popular posts from this blog

c++ - Difference between pre and post decrement in recursive function argument -

i have following sample code used pre-decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(--c); cout << c << endl; return; } } this function give output input 4 : dp3 dp2 dp1 dp0 0 1 2 3 but when use post decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(c--); cout << c << endl; return; } } output goes in infinite loop dp4 can explain me in detail why happens ? this happens because function(c--) called same value of c , when finishes c decremented. recursively called, hence called same value no chance of return , hit stack overflow error. assume this, int x = 1, y = 0; y = x++ result y == 1 , x == 2. if y = ++x , bot x , y 2.
Read more

php - Nothing but 'run(); ' when browsing to my local project, how do I fix this? -

i added new project. made mistake in projectname.conf file in sites-available apache2, led me reinstalling apache2. after reinstalling , re-enabling projects on every page of every project .. <body> run(); </body> .. i've run composer update, restarted service, restarted pc, checked config files, tried disabling new project. there nothing in error log, , access.log: 127.0.0.1 - - [15/may/2015:01:40:47 +0200] "get / http/1.1" 304 181 "-" "mozilla/5.0 (x11; ubuntu; linux x86_64; rv:38.0) gecko/20100101 firefox/38.0" maybe i'm forgetting apache2 reinstall? don't think did different last time installed it. looks haven't setup php correctly. take @ this great guide , maybe you're forgetting link php config apache2.
Read more

php - How can I echo out this array? -

i don't know how go grabbing data in variable , put foreach loop. class tree{ private $info = array( array('name'=>'jim','state'=>'nu','company'=>'nu','phone'=>array('cell'=>'5615111111','office'=>'5611111111'),'email'=>array('primary'=>'exs@example.com','ex@there.com')), array('name'=>'joe smith','city'=>'phoenix','phone'=>'4805551111','email'=>'jsmith@some_email.com'), array('name'=>'john doe','city'=>'chandler','company'=>'doe co.','email'=>array('jdoe@gmail.com','personal'=>'email@email.com'),'phone'=>'6025550002') ); } if you're inside of class, can access private variable using $this->variablename . example, i...
Read more