它非常简单。 首先从Sqlite数据库获得用户Name和所有与用户有关的数值,以掌握提交年份。 如果所有数值都为零,那么你就开始服务器程序。 如果数据库中的所有数值都直接用于下一次应用筛选。

EDIT

Pseudo Code-

- (IBAction)SubmitTapped:(id) sender {
  //Check if Database already contains userName and password 
  if(userName && password){
    //user name and password found in database
    //show next screen or authenticate user through web services as per your requirement.
   }
   else {
      //First time login
      //Validate user entered data like values of textfields.(Suggestion use DHValidation for validating textfields)

     BOOL validate = [self validateData];//a function to validate data using DHValidation create yourself.
    if(validate){
    //save login credentails into database
   //show next screen
     }
   }
}

我希望大家现在能够理解。

<>>>>>

-(void)check
{
    app.journeyList = [[NSMutableArray alloc]init];
    [self createEditableCopyOfDatabaseIfNeeded];

    NSString *filePath = [self getWritableDBPath];

    sqlite3 *database;

    if(sqlite3_open([filePath UTF8String], &database) == SQLITE_OK) {
        const char *sqlStatement = "SELECT Username,Password FROM UserInformation where Username=? and Password=?";
        sqlite3_stmt *compiledStatement;
        if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK)    {
            sqlite3_bind_text(compiledStatement, 1, [Uname.text UTF8String], -1, SQLITE_TRANSIENT);
            sqlite3_bind_text(compiledStatement, 2, [Password.text UTF8String], -1, SQLITE_TRANSIENT);
            //NSString *loginname= [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
            //          NSString *loginPassword = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];




        }
        if(sqlite3_step(compiledStatement) != SQLITE_ROW ) {
            //NSLog( @"Save Error: %s", sqlite3_errmsg(database) );
           // UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"UIAlertView" message:@"User is not valid" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
//            [alert show];
//            [alert release];
//            alert = nil;

            //we have no data into database so send request to webserver.
            yourAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
            if(appDelegate.internetConnectionStatus != NotReachable){
                //Network Available
                [self sendRequest];
            }
        }
        else {

            isUserValid = YES;
            if (isUserValid) {
                app = (JourneyAppDelegate *)[[UIApplication sharedApplication]delegate];
                TTabBar *tabbar=[[TTabBar alloc] init];
                [app.navigationController pushViewController:tabbar animated:YES];
                tabbar.selectedIndex = 0;



            }       
        }

        sqlite3_finalize(compiledStatement);
    }
    sqlite3_close(database);        
}



//this is used when the user first time log in the server and sends
-(void)sendRequest {

    UIDevice *device = [UIDevice currentDevice];
    NSString *udid = [device uniqueIdentifier];
    NSString *sysname = [device systemName];
    NSString *sysver = [device systemVersion];
    NSString *model = [device model];

    NSLog(@"idis:%@",[device uniqueIdentifier]);
    NSLog(@"system nameis :%@",[device systemName]);
    NSLog(@"System version is:%@",[device systemVersion]);
    NSLog(@"System model is:%@",[device model]);
    NSLog(@"device orientation is:%d",[device orientation]);

    NSString *post = [NSString stringWithFormat:@"Loginkey=%@&Password=%@&DeviceCode=%@&Firmware=%@&IMEI=%@",Uname.text,Password.text,model,sysver,udid];
    NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES]; 
    NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]]; 
    NSLog(@"%@",postLength);
    NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease]; 
    [request setURL:[NSURL URLWithString:@"http://192.168.0.1:96/JourneyMapperAPI?RequestType=Login"]]; 
    [request setHTTPMethod:@"POST"]; 
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"]; 
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; 
    [request setHTTPBody:postData];

    NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self];

    if (theConnection) {
        webData = [[NSMutableData data] retain];
        NSLog(@"%@",webData);
    }
    else 
    {

    }

}



-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response 
{   
    [webData setLength: 0]; 
} 

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 
{         
    [webData appendData:data]; 

} 

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error 
{     
    [connection release];  
    [webData release]; 

} 

-(void)connectionDidFinishLoading:(NSURLConnection *)connection 
{      
    NSString *loginStatus = [[NSString alloc] initWithBytes: [webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding]; 
    NSLog(@"%@",loginStatus);  
    // this is to perfrom insert opertion on the userinformation table

    NSString *json_string = [[NSString alloc] initWithData:webData encoding:NSUTF8StringEncoding]; 

    NSDictionary *result = [json_string JSONValue];
    //
    BOOL errortest = [[result objectForKey:@"isError"] boolValue];
    if(errortest == FALSE)
    {
        values = [result objectForKey:@"Result"];
        NSLog(@"Valid User");
    }
    else
    {
        NSLog(@"Invalid User");
    }

    NSMutableArray *results = [[NSMutableArray alloc] init];

    for (int index = 0; index<[values count]; index++) {
        NSMutableDictionary * value = [values objectAtIndex:index];
        Result * result = [[Result alloc] init];
        result.UserID = [value objectForKey:@"UserId"];
        result.FirstName = [value objectForKey:@"FirstName"];
        result.LastName =[value objectForKey:@"LastName"];
        result.Email =[value objectForKey:@"Email"];
        result.ProfileImage =[value objectForKey:@"ProfileImage"];
        result.ThumbnailImage =[value objectForKey:@"ThumbnailImage"];
        result.DeviceInfoId =[value objectForKey:@"DeviceInfoId"];
        NSLog(@"%@",result.UserID);


        [results addObject:result];
        [result release]; 
    }



    for (int index = 0; index<[results count]; index++) {
        Result * result = [results objectAtIndex:index];
        //save the object variables to database here


        [self createEditableCopyOfDatabaseIfNeeded];

        NSString *filePath = [self getWritableDBPath];

        sqlite3 *database;

        //this four lines of code are  for creating timestap and journeyID in userjourney table.
        //NSTimeInterval timeStamp = [[NSDate date] timeIntervalSince1970]; 
        //   NSNumber *timeStampObj = [NSNumber numberWithInt: timeStamp];
        //   NSLog(@"%@",timeStampObj);
        //   NSString *journeyid = [NSString stringWithFormat:@"%@_%@_%@", result.UserID, result.DeviceInfoId, timeStampObj];
        if(sqlite3_open([filePath UTF8String], &database) == SQLITE_OK) {
            const char *sqlStatement = "insert into UserInformation(UserID,DeviceId,Username,Password,FirstName,Email) VALUES (?,?,?,?,?,?)";
            sqlite3_stmt *compiledStatement;
            if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK)    {
                //sqlite3_bind_text( compiledStatement, 1, [journeyid UTF8String],-1,SQLITE_TRANSIENT);
                sqlite3_bind_text( compiledStatement, 1, [result.UserID UTF8String],-1,SQLITE_TRANSIENT);
                sqlite3_bind_text(compiledStatement, 2, [result.DeviceInfoId UTF8String],-1,SQLITE_TRANSIENT);
                sqlite3_bind_text(compiledStatement, 3, [Uname.text UTF8String],-1,SQLITE_TRANSIENT);
                sqlite3_bind_text(compiledStatement, 4, [Password.text UTF8String],-1,SQLITE_TRANSIENT);
                sqlite3_bind_text (compiledStatement, 5, [result.FirstName UTF8String],-1,SQLITE_TRANSIENT);
                sqlite3_bind_text (compiledStatement, 6, [result.Email UTF8String],-1,SQLITE_TRANSIENT);

            }
            if(sqlite3_step(compiledStatement) != SQLITE_DONE ) {
                NSLog( @"Save Error: %s", sqlite3_errmsg(database) );
            }
            else {
                UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"UIAlertView" message:@"Record added" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
                [alert show];
                [alert release];
                alert = nil;
            }

            sqlite3_finalize(compiledStatement);
        }
        sqlite3_close(database);   
    }

    [loginStatus release];           
    [connection release];  
    [webData release]; 
} 



-(IBAction)buttonPressed:(id)sender
{
    //it should be on application did finish launching

    [[Reachability sharedReachability] setHostName:kHostName];
    //Set Reachability class to notifiy app when the network status changes.
    [[Reachability sharedReachability] setNetworkStatusNotificationsEnabled:YES];
    //Set a method to be called when a notification is sent.
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:@"kNetworkReachabilityChangedNotification" object:nil];

    //it will be called automatically you don t need to expilictly call this function
   // [self updateStatus];


    //The above code should be in application did finish launching.


    //NSLog(<#NSString *format#>)
    //this is to select username and password from database.
    [self check];

    //Gpassq = Password.text;
    //Gunameq = Uname.text;

    //[self check];




}

- (void)reachabilityChanged:(NSNotification *)note {
    [self updateStatus];
}

- (void)updateStatus
{
    // Query the SystemConfiguration framework for the state of the device s network connections.
    self.internetConnectionStatus   = [[Reachability sharedReachability] internetConnectionStatus];
    if (self.internetConnectionStatus == NotReachable) {
        //show an alert to let the user know that they can t connect...
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Network Status" 
                                                        message:@"Sorry, our network guro determined that the network is not available. Please try again later." 
                                                       delegate:self 
                                              cancelButtonTitle:nil 
                                              otherButtonTitles:@"OK", nil];
        [alert show];
    } else {
        // If the network is reachable, make sure the login button is enabled.
        //_loginButton.enabled = YES;
    }
}