Objective-C:NSValue类的常见用法

特殊类型的包装类：数组、结构体(OC内部的、自定义的)、指针

 //
 //  main.m
 //  05-NSValue
 //
 //  Created by ma c on 15/8/17.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>
 typedef struct
 {
     char *name;
     int age;
     char gender;
 }Student;

 int main(int argc, const char * argv[])
 {
     @autoreleasepool
     {
         //NSValue测试
         //1.指针
         int num = ;
         int *p = &num;
         NSValue *value1 = [NSValue valueWithPointer:p];
         int *p2 = (int*)[value1 pointerValue];
         NSLog(@"num = %d",*(p2));

         //2.数组
         int arr[] = {,,,,};
         NSValue *value2 = [NSValue valueWithPointer:arr];
         int *p3 = (int*)[value2 pointerValue];
         for(int i=; i<; i++)
         {
             NSLog(@"%d",p3[i]);
         }

         //3.Foundation中常用的结构体:NSRange\NSRect\NSSize\NSPoint
         NSRange range = NSMakeRange(, );
         NSValue *value3 = [NSValue valueWithRange:range];
         NSRange range2 = [value3 rangeValue];
         NSLog(@"%@",NSStringFromRange(range2));

         NSRect rect = NSMakeRect(, , , );
         NSValue *value4 = [NSValue valueWithRect:rect];
         NSRect rect2 = [value4 rectValue];

         NSLog(@"%@",NSStringFromRect(rect2));

         //4.自定义的结构体
         Student stu = {"Tom",,'M'};
         NSValue *value5 = [NSValue valueWithBytes:&stu objCType:@encode(Student)];
         NSLog(@"%s",@encode(Student));//输出结构体类型

         Student stu2;
         [value5 getValue:&stu2];
         NSLog(@"name = %s,age = %i,gender = %c",stu2.name,stu2.age,stu2.gender);
     }
     return ;
 }