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;
}