我要评论前言
在ios 中实现对象序列化，需要遵行nscoding协议，然后对对象的每个属性进行归档和接档赋值，响应的操作比较繁琐。本文主要介绍 利用 runtime遍历属性 大大简化代码量，下面来看看详细的介绍吧。
具体实现代码如下:
1.先建立nsobject的分类, 定义可能用到的相关类型
static nsstring *inttype = @"i"; // int_32t(枚举int型) static nsstring *longtpye = @"l"; //long类型 static nsstring *longlongtype= @"q"; // longlong类型 static nsstring *booltype = @"b"; //bool类型 static nsstring *floattype = @"f"; // float static nsstring *doubletype = @"d"; // double static nsstring *booltype = @"c"; static nsstring *stringtype = @"nsstring"; // nsstring 类型 static nsstring *numbertype = @"nsnumber"; // nsnumber 类型 static nsstring *arraytype = @"arraytype";//array类型 static nsstring *imagetype = @"uiimage"; // uiimage 类型
然后在归档方法中便利自身的属性名称，并且取出自身属性对应的值，进行存储到本地。此时遍历类属性本身，用到了ivar指针（定义对象的实例变量，包括类型和名字），具体代码如下
//归档
- (void)encodewithcoder:(nscoder *)acoder
{
unsigned int count; // 属性个数
ivar *vararray = class_copyivarlist([self class], &count);
for (int i = 0; i < count; i++)
{
ivar var = vararray[i];
const char *cname = ivar_getname(var); // 属性名c字符串
nsstring *proname = [[nsstring stringwithutf8string:cname] substringfromindex:1]; //oc字符串,并且去掉下划线 _
const char *ctype = ivar_gettypeencoding(var); // 获取变量类型，c字符串
id value = [self valueforkey:proname];
nsstring *protype = [nsstring stringwithutf8string:ctype]; // oc 字符串
if ([protype containsstring:@"nsstring"]) {
protype = stringtype;
}
if ([protype containsstring:@"nsnumber"]) {
protype = numbertype;
}
if ([protype containsstring:@"nsarray"]) {
protype = arraytype;
}
if ([protype containsstring:@"uiimage"]) {
protype = imagetype;
}
// (5). 根据类型进行编码
if ([protype isequaltostring:inttype] || [protype isequaltostring:booltype] || [protype isequaltostring:booltype]) {
[acoder encodeint32:[value intvalue] forkey:proname];
}
else if ([protype isequaltostring:longtpye]) {
[acoder encodeint64:[value longvalue] forkey:proname];
}
else if ([protype isequaltostring:floattype]) {
[acoder encodefloat:[value floatvalue] forkey:proname];
}
else if ([protype isequaltostring:longlongtype] || [protype isequaltostring:doubletype]) {
[acoder encodedouble:[value doublevalue] forkey:proname];
}
else if ([protype isequaltostring:stringtype]) { // string 类型
[acoder encodeobject:value forkey:proname];
}
else if ([protype isequaltostring:numbertype]) {
[acoder encodeobject:value forkey:proname];
}
else if ([protype isequaltostring:arraytype]) {
[acoder encodeobject:value forkey:proname];
}
else if ([protype isequaltostring:imagetype]) { // image 类型
[acoder encodedataobject:uiimagepngrepresentation(value)];
}
}
free(vararray);
}
其次进行解档， 原理和归档差不多， 直接上代码
- (instancetype)initwithcoder:(nscoder *)adecoder
{
self = [self init];
if (self) {
unsigned int count;
ivar *vararray = class_copyivarlist([self class], &count);
for (int i = 0; i < count; i++) {
ivar var = vararray[i];
const char *cname = ivar_getname(var); // 属性名c字符串
nsstring *proname = [[nsstring stringwithutf8string:cname] substringfromindex:1]; //oc字符串,并且去掉下划线 _
const char *ctype = ivar_gettypeencoding(var); // 获取变量类型，c字符串
nsstring *protype = [nsstring stringwithutf8string:ctype]; // oc 字符串
if ([protype containsstring:@"nsstring"]) {
protype = stringtype;
}
if ([protype containsstring:@"nsnumber"]) {
protype = numbertype;
}
if ([protype containsstring:@"nsarray"]) {
protype = arraytype;
}
if ([protype containsstring:@"uiimage"]) {
protype = imagetype;
}
if ([protype isequaltostring:inttype] || [protype isequaltostring:booltype] || [protype isequaltostring:booltype]) {
int32_t number = [adecoder decodeint32forkey:proname];
[self setvalue:@(number) forkey:proname];
}
else if ([protype isequaltostring:longtpye]) {
int64_t number = [adecoder decodeint64forkey:proname];
[self setvalue:@(number) forkey:proname];
}
else if ([protype isequaltostring:floattype]) {
float number = [adecoder decodefloatforkey:proname];
[self setvalue:@(number) forkey:proname];
}
else if ([protype isequaltostring:longlongtype] || [protype isequaltostring:doubletype]) {
double number = [adecoder decodefloatforkey:proname];
[self setvalue:@(number) forkey:proname];
}
else if ([protype isequaltostring:stringtype]) { // string 类型
nsstring *string = [adecoder decodeobjectforkey:proname];
[self setvalue:string forkey:proname];
}
else if ([protype isequaltostring:numbertype]) {
nsstring *number = [adecoder decodeobjectforkey:proname];
[self setvalue:number forkey:proname];
}
else if ([protype isequaltostring:arraytype]) {
nsarray *array = [adecoder decodeobjectforkey:proname];
[self setvalue:array forkey:proname];
}
else if ([protype isequaltostring:imagetype]) { // image 类型
uiimage *image = [uiimage imagewithdata:[adecoder decodedataobject]];
[self setvalue:image forkey:proname];
}
}
}
return self;
}
最后也就是 存储方法 、 清除存储的本地缓存 和 获取本地存储数据的方法
//存储路径
- (nsstring *)filepathwithuniqueflagstring:(nsstring *)uniqueflag
{
nsstring *docpath = [nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes) lastobject];
nsstring *detailpath = [nsstring stringwithformat:@"%@_%@",uniqueflag,[nsstring stringwithutf8string:object_getclassname(self)]];
nsstring *path = [docpath stringbyappendingpathcomponent:detailpath];
return path;
}
//保存对象数据到本地
- (void)savedatatolocalwithuniqueflagkey:(nsstring *)uniqueflagkey
{
[nskeyedarchiver archiverootobject:self tofile:[self filepathwithuniqueflagstring:uniqueflagkey]];
}
//清空本地存储的对象数据
- (id)getdatafromlocalwithuniqueflagkey:(nsstring *)uniqueflagkey
{
return [nskeyedunarchiver unarchiveobjectwithfile:[self filepathwithuniqueflagstring:uniqueflagkey]];
}
//从本地获取对象数据
- (bool)removedatafromlocalwithuniqueflagkey:(nsstring *)uniqueflagkey
{
nserror *error = nil;
[[nsfilemanager defaultmanager] removeitematpath:[self filepathwithuniqueflagstring:uniqueflagkey] error:&error];
if (!error) {
return yes;
}
else {
return no;
}
}
完整项目下载地址如下：https://github.com/maxzhang123/mxcoding.git 或者可以本地下载地址：
总结
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