向远程地址服务器请求信息吗,xmPP(即时通讯)向远程服务器请求数据

首先在本地初始化一个数据库

- (void)initDatabase

{

//最终数据库路径

NSString *dbPath  &＃61; [NSHomeDirectory() stringByAppendingPathComponent:&＃64;"Documents/database.db"];

NSFileManager *fm &＃61; [NSFileManager defaultManager];

if(![fm fileExistsAtPath:dbPath])

{

EGODatabase* database &＃61; [EGODatabase databaseWithPath:dbPath];

strSql &＃61; &＃64;"creat table if not exists notice(id integer primary key asc,noticeid text,title text, image text,content text,timestamp text);";

[database executeQuery:strSql];

[database close];

&＃xff5d;

然后保存信息在本地数据库&＃xff0c;因为我做的时资讯&＃xff0c;所以有一个判断&＃xff0c;如果本地已经有这个资讯则直接返回&＃xff0c;如果有更新资讯就插入最新的资讯

-(void)saveNotice:(NoticeMessage *)notice

{

NSString *dbPath  &＃61; [NSHomeDirectory() stringByAppendingPathComponent:&＃64;"Documents/database.db"];

EGODatabase* database &＃61; [EGODatabase databaseWithPath:dbPath];

//查询是否已经存在&＃xff0c;如果存在就直接返回不插入

NSString *sqlQuery &＃61; [[NSString alloc]initWithFormat:&＃64;"select count(*) from notice where noticeid &＃61; %&＃64;",notice.strnotId];

//NSLog(&＃64;"%&＃64;",sqlQuery);

EGODatabaseResult *result &＃61; [database executeQuery:sqlQuery];

for(EGODatabaseRow* row in result) {

NSString* strTotal &＃61; [row stringForColumnAtIndex:0];

if ([strTotal integerValue] > 0) {

return;

}

}

NSString* sqlInsert &＃61; [[NSString alloc] initWithFormat:&＃64;"insert into notice(noticeid,title,date,image,content,timestamp) values([email protected],[email protected],[email protected],[email protected],[email protected],[email protected])",notice.strNoticeId,notice.strTitle,notice.strDate,notice.strImage,notice.strContent,notice.strTimeStamp];

[database executeQuery:sqlInsert];

NSLog(&＃64;"save message:%&＃64;",sqlInsert);

[database close];

}

我们在与服务器端同事沟通时做了一个资讯的id&＃xff0c;通过ID判断是否最新资讯&＃xff0c;所以会查询一下本地数据库里的id&＃xff0c;那么我就抽出了这个数据库方法&＃xff0c;将这个id赋给一个全局变量&＃xff0c;

在把这个全局变量赋给后面的请求。

//检查本地公告id

-(void)searchNoticeDataBase

{

EGODatabase* database &＃61; [EGODatabase databaseWithPath:[NSHomeDirectory() stringByAppendingPathComponent:&＃64;"Documents/database.db"]];

//查询是否已经存在最新公告

NSString *sqlQuery &＃61; [[NSString alloc]initWithFormat:&＃64;"select noticeid from notice group by category order by noticeid limit 1"];

//NSLog(&＃64;"%&＃64;",sqlQuery);

EGODatabaseResult *result &＃61; [database executeQuery:sqlQuery];

for(EGODatabaseRow* row in result)

{

NoticeMessage *msg &＃61; [[NoticeMessage alloc]init];

msg.strnotId &＃61; [row stringForColumn:&＃64;"noticeid"];

noticeId &＃61; msg.strnotId;

}

[database close];

}

请求的方法

-(void)checkNewNotice

{

NSUserDefaults *pref &＃61; [NSUserDefaults standardUserDefaults];

NSString* strToken &＃61; [pref stringForKey:&＃64;"logintoken"];

NSString *oldNoticeId &＃61; noticeId;

if (oldNoticeId &＃61;&＃61; nil) {

oldNoticeId &＃61; &＃64;"0";

}

//向管理平台登录&＃xff0c;获取token

NSString *strUrl &＃61; [NSString stringWithFormat:&＃64;"http://xxx.xx.x.xxx:xxxx/fxxxxxxxx?xxxx&＃61;%&＃64;&xxxx&＃61;%&＃64;",strToken,oldNoticeId];

NSLog(&＃64;"Chect new info %&＃64;",strUrl);

NSURL *url &＃61; [NSURL URLWithString:strUrl];

__block ASIHTTPRequest *request &＃61; [ASIHTTPRequest requestWithURL:url];

[request setCompletionBlock:^{

// Use when fetching text data

NSString *responseString &＃61; [request responseString];

NSLog(&＃64;"login result:%&＃64;",responseString);

NSError *error &＃61; nil;

NSData *jsonData &＃61; [responseString dataUsingEncoding:NSUTF8StringEncoding];

NSDictionary *dict &＃61; [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&error];

NSString* msgCode &＃61; [dict objectForKey:&＃64;"code"];

if ([msgCode isEqualToString:&＃64;"200"]) {

NSLog(&＃64;"get new info success!");

NSDictionary *noticeDict &＃61; [dict objectForKey:&＃64;"result"];

for (NSDictionary* dResult in noticeDict) {

NSString *strNoticeId &＃61; [dResult objectForKey:&＃64;"noticeid"];

NSString *strTitle &＃61; [dResult objectForKey:&＃64;"title"];

NSString *strDate &＃61; [dResult objectForKey:&＃64;"date"];

NSString *strImage &＃61; [dResult objectForKey:&＃64;"image"];

NSString *strContent &＃61; [dResult objectForKey:&＃64;"content"];

NSString *strTimeStamp &＃61; [dResult objectForKey:&＃64;"timestamp"];

NoticeMessage *notice &＃61; [[NoticeMessage alloc]init];

notice.strNoticeId &＃61; strNoticeId;

notice.strTitle &＃61; strTitle;

notice.strDate &＃61; strDate;

notice.strImage &＃61; strImage;

notice.strContent &＃61; strContent;

notice.strTimeStamp &＃61; strTimeStamp;

[self saveNotice:notice];

}

//重新加载资讯信息

[self loadNotice];

[self.tableValued reloadData];

//   [SVProgressHUD dismiss];

}

else if([msgCode isEqualToString:&＃64;"404"]) {

NSLog(&＃64;"找不到用户");

//  [SVProgressHUD showErrorWithStatus:&＃64;"用户名或密码有误"];

return;

}

else{

;// [SVProgressHUD dismiss];

}

NSLog(&＃64;"msgCode is %&＃64;",msgCode);

// Use when fetching binary data

//NSData *responseData &＃61; [request responseData];

}];

[request setFailedBlock:^{

NSError *error &＃61; [request error];

NSLog(&＃64;"login result:%&＃64;",error.description);

}];

[request startAsynchronous];

}

还需要一个从数据库载入的方法

- (void)loadNotice

{

if (!arrayNotice) {

arrayNotice &＃61; [[NSMutableArray alloc]init];

}

EGODatabase* database &＃61; [EGODatabase databaseWithPath:[NSHomeDirectory() stringByAppendingPathComponent:&＃64;"Documents/database.db"]];

//查询所有的公告

NSString *sqlQuery &＃61; [[NSString alloc]initWithFormat:&＃64;"select distinct * from notice  order by timestamp"];

//NSLog(&＃64;"%&＃64;",sqlQuery);

EGODatabaseResult *result &＃61; [database executeQuery:sqlQuery];

for(EGODatabaseRow* row in result) {

NoticeMessage *msg &＃61; [[NoticeMessage alloc]init];

msg.strNoticeId &＃61; [row stringForColumn:&＃64;"noticeid"];

msg.strTitle &＃61; [row stringForColumn:&＃64;"title"];

msg.strContent &＃61; [row stringForColumn:&＃64;"content"];

msg.strTimeStamp &＃61; [row stringForColumn:&＃64;"timestamp"];

[arrayNotice insertObject:msg atIndex:0];

}

[database close];

}

那么最后&＃xff0c;我是在登录的时候调用请求的方法

[self checkNewNotice]

说实话我还是个小菜鸟&＃xff0c;这个项目真的帮助我提升了许多&＃xff0c;虽然很多还是不懂&＃xff0c;但我都觉得我已经是高富帅了

原文&＃xff1a;http://www.cnblogs.com/tuhaoYY/p/3850894.html