我正在尝试在Objective C中构建一个包含为我的应用程序提供Web服务和数据库方法的类。在这个类中，我想调用Web服务并获取员工记录，然后将它们加载到SQL表中，以便以后在视图中使用。
当所有代码都在视图中时，我得到了这个工作，但在尝试创建这个新类（我称之为GetEmployee）时，我遇到了问题。我不太清楚如何从另一个类访问属性和方法。
这是我的GetEmployee类
#import <Foundation/Foundation.h>
#import "employee.h"
#import "FMDatabase.h"
#import "FMDatabaseAdditions.h"
#import "FMDatabasePool.h"
#import "FMDatabaseQueue.h"
#import "FMResultSet.h"
#import "Utility.h"
@interface GetEmployee : NSObject
{
NSMutableArray *employees;
}
@property (nonatomic, copy) NSString *databaseName;
@property (nonatomic, copy) NSString *databasePath;
- (void)updateEmployeeData;
- (void)callWebService;
- (void)fetchedData:(NSData *)responseData;
- (NSMutableArray *) getEmployees;
@end
实施
#define kBgQueue dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
#define scoularDirectoryURL [NSURL URLWithString: @"https://XXXXXXXXX/mobile/mobilede.nsf/restServices.xsp/PeopleByName"]
#import "GetEmployee.h"
#import "FMDatabase.h"
#import "FMDatabaseAdditions.h"
#import "FMResultSet.h"
@implementation GetEmployee
- (id) init
{
if (self = [super init])
{
self.databaseName = @"employees.db";
}
return self;
}
#pragma
- (void)updateEmployeeData{
//Delete database if it exists and then copy fresh DB
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDir = [documentPaths objectAtIndex:0];
self.databasePath = [documentDir stringByAppendingPathComponent:self.databaseName];
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL success;
success = [fileManager fileExistsAtPath:self.databasePath];
if (success) {
[fileManager removeItemAtPath:self.databasePath error:nil];
}
NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:self.databaseName];
[fileManager copyItemAtPath:databasePathFromApp toPath:self.databasePath error:nil];
//Call the web service
[self callWebService];
[self populateDatabase];
}
- (void) callWebService {
dispatch_sync(kBgQueue, ^{
NSData* data = [NSData dataWithContentsOfURL:
scoularDirectoryURL];
[self performSelectorOnMainThread:@selector(fetchedData:) withObject:data waitUntilDone:YES];
});
}
- (void)fetchedData:(NSData *)responseData {
NSError* error;
NSMutableArray *jsonArray = [NSJSONSerialization JSONObjectWithData: responseData options: NSJSONReadingMutableContainers error: &error];
id jsonObject = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
employees = [[NSMutableArray alloc] init];
if (!jsonArray) {
} else {
for (jsonObject in jsonArray){
employee *thisEmployee = [employee new];
thisEmployee.fullName = [jsonObject objectForKey:@"$13"];
thisEmployee.ste = [jsonObject objectForKey:@"state"];
thisEmployee.city = [jsonObject objectForKey:@"city"];
[employees addObject:thisEmployee];
}
}
}
-(void) populateDatabase {
////Call the web service and populate the db
//dispatch_sync(kBgQueue, ^{
// NSData* data = [NSData dataWithContentsOfURL:
// scoularDirectoryURL];
// [self performSelectorOnMainThread:@selector(fetchedData:) withObject:data waitUntilDone:YES];
//});
//Populate the db
FMDatabase *db = [FMDatabase databaseWithPath:[Utility getDatabasePath]];
[db open];
for (employee *thisemployee in employees) {
BOOL success = [db executeUpdate:@"INSERT INTO employees (fullname,city,state) VALUES (?,?,?);",thisemployee.fullName,thisemployee.city,thisemployee.ste, nil];
if (success) {} // Only to remove success error
}
[db close];
}
- (NSMutableArray *) getEmployees
{
//NSMutableArray *employees = [[NSMutableArray alloc] init];
employees = [[NSMutableArray alloc] init];
FMDatabase *db = [FMDatabase databaseWithPath:[Utility getDatabasePath]];
[db open];
FMResultSet *results = [db executeQuery:@"SELECT * FROM employees"];
while([results next])
{
employee *thisEmployee = [employee new];
thisEmployee.fullName = [results stringForColumn:@"fullname"];
thisEmployee.city = [results stringForColumn:@"city"];
thisEmployee.ste = [results stringForColumn:@"state"];
[employees addObject:thisEmployee];
}
[db close];
return employees;
}
@end
这是MasterViewController
头
#import <UIKit/UIKit.h>
#import "employee.h"
#import "FMDatabase.h"
#import "FMResultSet.h"
#import "FMDatabaseAdditions.h"
#import "Utility.h"
#import "GetEmployee.h"
@interface MasterViewController : UITableViewController
{
NSMutableArray *employees;
//GetEmployee *ScoularEmployees;
}
@end
实施
#define kBgQueue dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
#define scoularDirectoryURL [NSURL URLWithString: @"https://xxxxxxxx/mobile/mobilede.nsf/restServices.xsp/PeopleByName"]
#import "MasterViewController.h"
#import "DetailViewController.h"
#import "employee.h"
#import "GetEmployee.h"
@interface MasterViewController () {
NSMutableArray *_objects;
}
@property(strong, nonatomic) GetEmployee *ScoularEmployees;
@end
@implementation MasterViewController
- (void)awakeFromNib
{
[super awakeFromNib];
}
- (void)viewDidLoad
{
[super viewDidLoad];
//GetEmployee *ScoularEmployees = [[GetEmployee alloc] init];
[self.ScoularEmployees init];
//[self.ScoularEmployees init];
//_ScoularEmployees = [[GetEmployee alloc] init];
//[_ScoularEmployees getEmployees];
//GetEmployee *ScoularEmployees = [[GetEmployee alloc] init];
//GetEmployee *thisEmployeeData = [[GetEmployee alloc] init];
//[self.ScoularEmployees updateEmployeeData];
//[self.ScoularEmployees getEmployees];
//[ScoularEmployees updateEmployeeData];
//[ScoularEmployees getEmployees];
}
#pragma mark - Table View
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return employees.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
NSString *fullName = [[employees objectAtIndex:indexPath.row] valueForKey:@"fullName"];
cell.textLabel.text = fullName;
return cell;
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the specified item to be editable.
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
[_objects removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
} else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
}
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:@"showDetail"]) {
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
employee *dtlEmployee = [employees objectAtIndex:indexPath.row];
[[segue destinationViewController] setDetailItem:dtlEmployee];
}
}
- (void)fetchedData:(NSData *)responseData {
NSError* error;
NSMutableArray *jsonArray = [NSJSONSerialization JSONObjectWithData: responseData options: NSJSONReadingMutableContainers error: &error];
id jsonObject = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
//employees = [[NSMutableArray alloc] init];
if (!jsonArray) {
} else {
//NSMutableArray *employees = [[NSMutableArray alloc ]init];
for (jsonObject in jsonArray){
employee *thisEmployee = [employee new];
thisEmployee.fullName = [jsonObject objectForKey:@"$13"];
thisEmployee.ste = [jsonObject objectForKey:@"state"];
thisEmployee.city = [jsonObject objectForKey:@"city"];
[employees addObject:thisEmployee];
}
}
}
//-(NSMutableArray *) getEmployees
//{
//NSMutableArray *employees = [[NSMutableArray alloc] init];
//employees = [[NSMutableArray alloc] init];
// FMDatabase *db = [FMDatabase databaseWithPath:[Utility getDatabasePath]];
// [db open];
// FMResultSet *results = [db executeQuery:@"SELECT * FROM employees"];
//
// while([results next])
// {
// employee *thisEmployee = [employee new];
// thisEmployee.fullName = [results stringForColumn:@"fullname"];
// thisEmployee.city = [results stringForColumn:@"city"];
// thisEmployee.ste = [results stringForColumn:@"state"];
// //[employees addObject:thisEmployee];
// }
//
// [db close];
//
// return employees;
// return true;
//}
@end
非常感谢任何帮助。
我认为很清楚，但我可以看到它不是。在视图类中，我希望能够加载一个名为* employees的NSMutableArray，它来自SQLLite数据库并在屏幕上显示出来。我试图在GetEmployee类中集中数据访问的代码。该类中的所有内容都处理数据 - Web服务，将数据加载到数据库，以及从数据库中获取数据。因此，在该类中，我有一个方法“getEmployees”，它从数据库获取数据并将其加载到NSMutableArry中。所以这就是问题，在类中我无法访问GetEmpployee中的方法或属性。这是我的问题。
答案 0 :(得分：0)
无需阅读您发布的所有代码......
对于使用Class方法，语法为：
[ClassName methodName];
[ClassName anotherMethod:withArguments];
使用此语法调用的方法在相应的.h文件中将如下所示：
+(void)methodName;
+(void)anotherMethod:(NSNumber*)number;
对于使用实例方法，语法为：
ClassName myObj = [[ClassName alloc] init];
[myObj someMethod];
[myObj someOtherMethod:withArguments];
使用此语法调用的方法在相应的.h文件中将如下所示：
-(void)someMethod;
-(void)someOtherMethod:(NSString*)parameter;