上个项目的一些反思 III

离线缓存

之前的项目因为实时性要求比较高,所以一打开客户端,就开始做网络请求.现在想想,是没有做内容的离线缓存.这个问题,我没意识到.产品经理也没有意识到...

我觉得Archiver,来做比较合适,可复写.可直接从存储中读取model,(当然要在相应的model里实现NSCoding协议)代码如下

#pragma mark ============实现NSCoding协议 

//归档
- (void)encodeWithCoder:(NSCoder *)Coder
{

    NSDate *  senddate=[NSDate date];

    NSDateFormatter  *dateformatter=[[NSDateFormatter alloc] init];

    [dateformatter setDateFormat:@"YYYY-MM-dd,hh:mm:ss"];

    NSString *str = [NSString stringWithFormat:@"Cached@:%@",[dateformatter stringFromDate:senddate]];

    [Coder encodeObject:_citynm forKey:@"CityName"];
    [Coder encodeObject:_weather forKey:@"Weather"];
    [Coder encodeObject:_temperature_curr forKey:@"NowTemp"];
    [Coder encodeObject:str forKey:@"days"];
    [Coder encodeObject:UIImagePNGRepresentation(_Logo) forKey:@"img"];

}

//解档
- (nullable instancetype)initWithCoder:(NSCoder *)Decoder // NS_DESIGNATED_INITIALIZER
{

    if (self = [super init]) {

        self.citynm = [Decoder decodeObjectForKey:@"CityName"];
        self.weather = [Decoder decodeObjectForKey:@"Weather"];
        self.temperature_curr = [Decoder decodeObjectForKey:@"NowTemp"];
        self.days   =   [Decoder decodeObjectForKey:@"days"];
        self.Logo = [UIImage imageWithData:[Decoder decodeObjectForKey:@"img"]];

    }

    return self;
}

Archiver的封装

#import <Foundation/Foundation.h>

@interface ArchiverCache : NSObject

/**
*  归档
*
*  @param model model
*  @param Key   Key
*/
-(void)EncoderDoWithModel:(id)model withKey:(NSString*)Key;

/**
 *  反归档
 *
 *  @param Key
 *
 *  @return (id)Model
 */
-(id)UncoderDoWith:(NSString*)Key;

@end

====================.M=================

#import "ArchiverCache.h"

@implementation ArchiverCache

//archiver
-(void)EncoderDoWithModel:(id)model withKey:(NSString *)Key
{
    NSMutableData *data = [[NSMutableData alloc] init];

    //创建归档辅助类
    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];

    //编码
    [archiver encodeObject:model forKey:Key];
    //结束编码
    [archiver finishEncoding];
    //写入

    if ([data writeToFile:[self GetFilePath] atomically:YES]) {

        NSLog(@"Cache Set Success");

    }else{

        NSLog(@"Cache Set Fail");

    }

}

//Unarchiver
-(id)UncoderDoWith:(NSString *)Key
{
    ///////////////////////解档
    NSData *_data = [[NSData alloc] initWithContentsOfFile:[self GetFilePath]];
    //解档辅助
    NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:_data];

    //解码并解档出model
    id Wm = [unarchiver decodeObjectForKey:Key];
    //关闭解档
    [unarchiver finishDecoding];

    return Wm;
}

-(NSString *)GetFilePath
{
    NSArray *arr = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
    //虽然该方法返回的是一个数组，但是由于一个目标文件夹只有一个目录，所以数组中只有一个元素。
    NSString *cachePath = [arr lastObject];

    NSString *filePath = [cachePath stringByAppendingPathComponent:@"Model"];
//    NSLog(@"%@",filePath);

    return filePath;
}
@end

调用,在这个例子里,每次进行model操作的时候,都会直接进行归档操作.这样可以保持归档里的数据都是最新的.

-(id)NetViewModelWithCache
{
    //读取缓存...
    ArchiverCache *ar = [[ArchiverCache alloc] init];
    //需在相应的model实现 initWithCoder;
    WeatherModel *Wm = [ar UncoderDoWith:@"weather"];

    return Wm;
}

-(id)ConvertToModel:(id)Data
{

    WeatherModel *model = [[WeatherModel alloc] initWithDictionary:Data];

    ///转成模型,同时把IMG给下载了.....由于API里的ICON是GIF,为了省事,这里直接另找了一张图.(可用sdwebimage来处理gif)
    NSString *imageURLStr = @"http://pic.58pic.com/58pic/15/48/73/04f58PIC37y_1024.png";

    NSData *imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:imageURLStr]];

    model.Logo = [UIImage imageWithData:imageData];

    ArchiverCache *ar = [[ArchiverCache alloc] init];

    //需在相应的model实现 encodeWithCoder;
    [ar EncoderDoWithModel:model withKey:@"weather"];

    return model;
}