Description & amp; debugDescription & amp; runtime (debug model in debug mode), describe

Description & debugDescription & runtime (debug model in debug mode), describe
Description

During development, many models are often used to load attributes. during development, debugging is often performed to check whether the attribute values in the model are correct.objective-cUsed inNSLog("%@",model)This line of code is printedmodelIs not the result we want ~! Figure:
So the question is coming again? Is there a way to solve this problem? The answer is yes ~! You only need to override- (NSString *)descriptionMethod. The following code:

. H file

#import <Foundation/Foundation.h>@interface TestModel : NSObject@property (copy,nonatomic) NSString *text;@property (assign,nonatomic) NSInteger index;@end

. M file

#import "TestModel.h"@implementation TestModel- (NSString *)description {    return [NSString stringWithFormat:@"text:%@--index:%zi",self.text,self.index];}@end

ThenNSLog("%@",model)This line of code can print the desired results. See:
The problem persists...
If the model containsNMultiple Attributes, possibly10, Possibly20... Is it necessarydescriptionIn the method, write the attributes one by one and splice them to return? You don't have to worry about it. It's a pain in my eyes... so we can use it.runtimeTechnology to dynamically obtain attributes and return the. m file code modified as follows:

Modified. m file

# Import "TestModel. h "# import <objc/runtime. h> // import the runtime header file @ implementation TestModel-(NSString *) description {// initialize a dictionary NSMutableDictionary * dictionary = [NSMutableDictionary dictionary]; // obtain all attributes of the current class uint count; objc_property_t * properties = class_copyPropertyList ([self class], & count ); // cyclically use KVC to obtain the value of each attribute for (int I = 0; I <count; I ++) {objc_property_t property = properties [I]; NSString * name = @ (Property_getName (property); id value = [self valueForKey: name]? : @ "Nil"; // The default value is the nil string [dictionary setObject: value forKey: name]; // load it into the dictionary} // release free (properties ); // return [NSString stringWithFormat: @ "<% @: % p> -- % @", [self class], self, dictionary];} @ end

Then printmodelSuch:

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DebugDescription

The problem persists ..
In the projectNSLogThere are also many statements.descriptionMethod. Many Attributes are printed on the console. It looks uncomfortable ~~ Another problem is that sometimes we don't need to printmodelSo rewrite it.descriptionMethodCounterproductiveNow! All, there is now a solution that is rewrittendebugDescriptionMethod
What isdebugDescription? ActuallydebugDescriptionAnddescriptionIs the same, but the only difference isdebugDescriptionYesXcodeUse in the consolepoCalled during command ~!
WhiledebugDescriptionIs actually called.descriptionMethod
So, in the development process andmodelDuring debugging, I recommend RewritingdebugDescriptionMethod instead of rewritingdescriptionMethod. When printingmodelIn the console.poCommand.. M file

# Import "TestModel. h "# import <objc/runtime. h> // import the runtime header file @ implementation TestModel // rewrite debugDescription, instead of description-(NSString *) debugDescription {// declare a dictionary NSMutableDictionary * dictionary = [NSMutableDictionary]; // obtain all attributes of the current class uint count; objc_property_t * properties = class_copyPropertyList ([self class], & count ); // cyclically use KVC to obtain the value of each attribute for (int I = 0; I <count; I ++) {objc_property_t Property = properties [I]; NSString * name = @ (property_getName (property); id value = [self valueForKey: name]? : @ "Nil"; // The default value is the nil string [dictionary setObject: value forKey: name]; // load it into the dictionary} // release free (properties ); // return [NSString stringWithFormat: @ "<% @: % p> -- % @", [self class], self, dictionary];} @ end

As shown in, they are used respectively.NSLogAndpoCommand Printing

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Result:

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This achieves what we want, if you need to printmodelAnd then usepoCommand