我们新建一个Xcode工程在控制台打印一些简单的信息，在这里以一个字典为例：
NSDictionary *dict = @{
@"userName":@"刘高见",
@"sex":@"man",
@"des":@{
@"message":@"我是一个iOS开发爱好者",
@"title":@"同时也是你的不到的爸爸",
@"reson":@"为什么这么说呢，因为我XX啊"
},
};
NSLog(@"%@",dict);
what's the Fuck!!!!
什么鬼，堂堂的中华大地，中文怎么就不能好好的展示。兄台莫慌张，着其实是因为编码问题导致的乱码所致的。那么，怎么解决呢？
首先，我们知道在代码打印或者执行po操作打印的时候，有几个系统方法会被调用：
-(NSString *)descriptionWithLocale:(id)locale indent:(NSUInteger)level;
-(NSString *)descriptionWithLocale:(id)locale;
-(NSString *)debugDescription;
关于这几个方法何时调用，在此不在阐述：
我们可以从这几个方法着手，重写方法的实现内容，实现中文标准输出的效果。废话不多说，代码如下：
#ifdef DEBUG
#import "LGJStandardLog.h"
#import <objc/runtime.h>
@implementation NSObject (LGJStandardLog)
/**
将对象转化成json字符串
*/
-(NSString *)convertToJsonString{
//判断能不能转化 不能转化返回nil
if (![NSJSONSerialization isValidJSONObject:self]) {
return nil;
}
NSError *error = nil;
//NSJSONWritingOptions的值有两种情况
//NSJSONWritingPrettyPrinted是将生成的json数据格式化输出
//NSJSONWritingSortedKeys是将生成的json数据不尽兴格式化输出 在一行上显示
NSJSONWritingOptions jsonOptions = NSJSONWritingPrettyPrinted;
if (@available(iOS 11.0, *)) {
//11.0之后，可以将JSON按照key排列后输出，看起来会更舒服
jsonOptions = NSJSONWritingPrettyPrinted | NSJSONWritingSortedKeys;
}
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:self options:NSJSONWritingPrettyPrinted error:&error];
if (error || !jsonData) {
return nil;
}
NSString *jsonString = [[NSString alloc]initWithData:jsonData encoding:NSUTF8StringEncoding];
return jsonString;
}
@end
/**
方法交换
*/
static inline void lgj_swizzleSelector(Class class, SEL originalSelector, SEL swizzledSelector) {
Method originalMethod = class_getInstanceMethod(class, originalSelector);
Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
BOOL addMethod = class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));
if (addMethod) {
class_replaceMethod(class, swizzledSelector,method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));
}else{
method_exchangeImplementations(originalMethod, swizzledMethod);
}
}
@implementation NSDictionary (LGJStandardLog)
/**
改方法是在代码控制打印的时候调用
*/
-(NSString *)standardlog_descriptionWithLocale:(id)locale{
NSString *result = [self convertToJsonString];
if (!result) {
//在此有些同学会一脸懵逼 这不是在掉自己么 呵呵呵呵。。。。。。因为在load方法执行的z时候已经执行了方法的交换 此时调用standardlog_descriptionWithLocale方法相当于调用系统的descriptionWithLocale
result = [self standardlog_descriptionWithLocale:locale];
return result;
}
return result;
}
/**
改方法是在代码控制打印的时候调用
*/
-(NSString *)standardlog_descriptionWithLocale:(id)locale indent:(NSUInteger)level{
NSString *result = [self convertToJsonString];
if (!result) {
result = [self standardlog_descriptionWithLocale:locale indent:level];
return result;
}
return result;
}
/**
改方法是在控制太po命令打印的时候调用
*/
-(NSString *)standardlog_debugDescription{
NSString *result = [self convertToJsonString];
if (!result) {
result = [self standardlog_debugDescription];
return result;
}
return result;
}
/**
方法交换的实现
*/
+(void)load{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class class = [self class];
lgj_swizzleSelector(class, @selector(debugDescription), @selector(standardlog_debugDescription));
lgj_swizzleSelector(class, @selector(descriptionWithLocale:indent:), @selector(standardlog_descriptionWithLocale:indent:));
lgj_swizzleSelector(class, @selector(descriptionWithLocale:), @selector(standardlog_descriptionWithLocale:));
});
}
@end
@implementation NSArray (LGJStandardLog)
-(NSString *)standardlog_descriptionWithLocale:(id)locale{
NSString *result = [self convertToJsonString];
if (!result) {
result = [self standardlog_descriptionWithLocale:locale];
return result;
}
return result;
}
-(NSString *)standardlog_descriptionWithLocale:(id)locale indent:(NSUInteger)level{
NSString *result = [self convertToJsonString];
if (!result) {
result = [self standardlog_descriptionWithLocale:locale indent:level];
return result;
}
return result;
}
-(NSString *)standardlog_debugDescription{
NSString *result = [self convertToJsonString];
if (!result) {
result = [self standardlog_debugDescription];
return result;
}
return result;
}
/**
方法交换的实现
*/
+(void)load{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class class = [self class];
lgj_swizzleSelector(class, @selector(debugDescription), @selector(standardlog_debugDescription));
lgj_swizzleSelector(class, @selector(descriptionWithLocale:indent:), @selector(standardlog_descriptionWithLocale:indent:));
lgj_swizzleSelector(class, @selector(descriptionWithLocale:), @selector(standardlog_descriptionWithLocale:));
});
}
@end
#endif
使用起来相当简单，直接把LGJStandardLog类扔进工程中，无需任何操作，即可解决问题。
我爱我的国
