iOS Advanced Development ~runtime (II)

6. Get all the methods of a class:

U_int count;

Method * methods = Class_copymethodlist ([Customclass class], &count);

for (int i = 0; i < count; i++) {

SEL name = Method_getname (Methods[i]);

NSString * StrName = [nsstring stringwithcstring:sel_getname (name) encoding:nsutf8stringencoding];

NSLog (@ "%@", strName);

}

Operation Result:

2014-10-20 11:57:27.884 runtimetest[10939:303] Fun1

2014-10-20 11:57:27.886 runtimetest[10939:303] Fun3

2014-10-20 11:57:27.886 runtimetest[10939:303] VarTest1

2014-10-20 11:57:27.886 runtimetest[10939:303] SetVarTest1:

2014-10-20 11:57:27.887 runtimetest[10939:303] VarTest2

2014-10-20 11:57:27.887 runtimetest[10939:303] SetVarTest2:

2014-10-20 11:57:27.887 runtimetest[10939:303] VarTest3

2014-10-20 11:57:27.888 runtimetest[10939:303] SetVarTest3:

7

Get all properties of a class

U_int count;

objc_property_t * Properties = Class_copypropertylist ([Customclass class], &count);

for (int i = 0; i < count; i++) {

const char * propertyname = Property_getname (Properties[i]);

NSString * StrName = [NSString stringwithcstring:propertyname encoding:nsutf8stringencoding];

NSLog (@ "%@", strName);

}

Operation Result:

2014-10-20 12:01:23.508 runtimetest[11167:303] VarTest1

2014-10-20 12:01:23.510 runtimetest[11167:303] VarTest2

2014-10-20 12:01:23.510 runtimetest[11167:303] VarTest3

8. Get/Set property variables for class

Gets the value of the global variable (myfloat is a property variable for the class)

-(void) Getinstancevar {

float Myfloatvalue;

object_getinstancevariable (self,"Myfloat", (void*) &myfloatvalue);

NSLog (@ "%f", Myfloatvalue);

}

Set the value of a global variable

-(void) Setinstancevar {

float newvalue = 10.00f;

unsigned int addr = (unsignedint) &newValue;

Object_setinstancevariable(self,"Myfloat", * (float*) addr);

NSLog (@ "%f", myfloat);

}

9. Determine the type of a property of a class

-(void) Getvartype {

Classcustomclass *obj = [Classcustomclassnew];

Ivar var = class_getinstancevariable(object_getclass(obj),"VarTest1");

Const char* typeencoding =ivar_gettypeencoding (var);

NSString *stringtype = [NSStringstringwithcstring: typeencodingencoding: nsutf8stringencoding ];

if ([StringType hasprefix:@ "@"]) {

Handle class case

NSLog(@ "Handle class case");

} Else if ([StringTypehasprefix:@ "I"]) {

handle INT Case

NSLog(@ "Handle int case");

} Else if ([StringTypehasprefix:@ "F"]) {

Handle float case

NSLog(@ "Handle float case");

} Else

{

}

}

10. Get the name of the property by its value (reflection mechanism)

-(NSString *) Nameofinstance: (ID) instance

{

unsigned int numivars =0;

nsstring *key=nil;

Describes the instance variables declared by a class.

Ivar * Ivars = class_copyivarlist ([Classcustomclassclass], &numivars);

For (int i = 0; i < Numivars; i++) {

Ivar Thisivar = ivars[i];

const Char *type =ivar_gettypeencoding (thisivar);

NSString *stringtype = [NSStringstringwithcstring: typeencoding: nsutf8stringencoding];

It's not class , it's skipped.

if (![ StringType Hasprefix:@ "@"]) {

continue;

}

Reads the value of an instance variable in an object. Object_getivar This method, when a non-Objective-c object is encountered and is directly crash

if ((object_getivar (allobj, thisivar) = = instance)) {

Returns the name of an instance variable.

key = [NSStringstringwithutf8string: Ivar_getname(Thisivar)];

Break ;

}

}

Free (ivars);

return key;

}

Test code:

AllObj = [Classcustomclassnew];

allobj. VarTest1 [email protected] "vartest1string";

allobj. VarTest2 [email protected] "vartest2string";

allobj. VARTEST3 [email protected] "vartest3string";

nsstring *str = [selfnameofinstance:@ "vartest1string"];

NSLog (@ "str:%@", str);

Printing results:

2013-07-26 16:26:26.271 Highoc[7081:c07] Str:vartest1

iOS Advanced Development ~runtime (II)