在我的应用程序中，我使用singleton类和sqlite db
这是我的单身人士课程：
#import <Foundation/Foundation.h>
@interface LoggedinUser : NSObject
{
// NSMutableArray *questionIDs;
}
+ (LoggedinUser *)sharedCenter;
@property (nonatomic,strong) NSString *email;
@property(nonatomic,strong)NSString *firmID;
@property (nonatomic,strong) NSString *name;
@property(nonatomic,strong)NSString *surname;
@property (nonatomic,strong) NSString *userTypeID;
@property(nonatomic,strong)NSString *firmName;
@property(nonatomic,strong)NSString *userID;
@property(nonatomic,strong)NSString *dbFileName;
@property(nonatomic,strong)NSString *answerdbFileName;
@property(nonatomic,strong)NSString *lastOrderIndex;
@property(nonatomic,strong)NSMutableArray *questionIDs;
@property(nonatomic,strong)NSString *programID;
@property(nonatomic,strong)NSString *merchantID;
@property(nonatomic,strong)UIViewController *myQuestionView;
@end
#import "LoggedinUser.h"
@implementation LoggedinUser
@synthesize userID,surname,name,userTypeID,email,firmID,firmName,dbFileName,answerdbFileName,lastOrderIndex,programID,questionIDs,merchantID,myQuestionView;
static LoggedinUser *sharedLoggedinUser = nil; // static instance variable
+ (LoggedinUser *)sharedCenter {
static LoggedinUser *sharedInstance = nil;
if (!sharedInstance) {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [[super allocWithZone:NULL] init];
// custom initialization
});
}
return sharedInstance;
}
- (id)init {
if ( (self = [super init]) ) {
questionIDs = [[NSMutableArray alloc] init];
myQuestionView=[[UIViewController alloc] init];
}
return self;
}
+ (id)allocWithZone:(NSZone *)zone {
return [self sharedCenter];
}
- (id)copyWithZone:(NSZone *)zone {
return self;
}
-(void)dealloc {
//[super dealloc];
}
@end
和我的DBHelper对象：
#import "DBHelper.h"
#import "Merchant.h"
#import "QuestionChoices.h"
#import "Question.h"
#import "LoggedinUser.h"
static DBHelper *sharedInstance = nil;
static sqlite3 *database = nil;
static sqlite3_stmt *statement = nil;
@implementation DBHelper
+(DBHelper*)getSharedInstance:(NSString*)dbname{
if (!sharedInstance) {
sharedInstance = [[super allocWithZone:NULL]init];
[sharedInstance createDB:dbname];
}
return sharedInstance;
}
-(BOOL)createDB:(NSString *)dbname{
NSString *docsDir;
NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0];
// Build the path to the database file
databasePath = [[NSString alloc] initWithString:
[docsDir stringByAppendingPathComponent: dbname]];
return true;
}
- (NSMutableArray*) getRegions
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:@"select ID,NAME from T_REGION"];
const char *query_stmt = [querySQL UTF8String];
NSMutableArray *regionNames = [[NSMutableArray alloc]init];
NSMutableArray *regionIDs = [[NSMutableArray alloc]init];
NSMutableDictionary *firstOptionDic =[[NSMutableDictionary alloc] init];
NSMutableArray *mainArray = [[NSMutableArray alloc]init];
if (sqlite3_prepare_v2(database,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
[firstOptionDic setValue:@"Seçiniz" forKeyPath:@"name"];
[firstOptionDic setValue:@"0" forKeyPath:@"ids"];
[mainArray addObject:firstOptionDic];
while (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *ids = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 0)];
[regionIDs addObject:ids];
NSString *name = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 1)];
[regionNames addObject:name];
}
sqlite3_finalize(statement);
//sqlite3_close(database);
for (int index = 0; index<regionNames.count; index++) {
NSMutableDictionary *dataAddDic =[[NSMutableDictionary alloc]init];
[dataAddDic setValue:[regionNames objectAtIndex:index] forKeyPath:@"name"];
[dataAddDic setValue:[regionIDs objectAtIndex:index] forKeyPath:@"ids"];
[mainArray addObject:dataAddDic];
}
return mainArray;
}
else
{
NSLog(@"problem");
}
}
return nil;
}
- (NSMutableArray*) getCityByRegionID:(NSString *) regionID
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:@"select ID,NAME from T_CITY where REGION_ID=%@ order by ORDER_NO",regionID];
const char *query_stmt = [querySQL UTF8String];
NSMutableArray *cityNames = [[NSMutableArray alloc]init];
NSMutableArray *cityIDs = [[NSMutableArray alloc]init];
NSMutableArray *mainArray = [[NSMutableArray alloc]init];
NSMutableDictionary *firstOptionDic =[[NSMutableDictionary alloc] init];
if (sqlite3_prepare_v2(database,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
[firstOptionDic setValue:@"Seçiniz" forKeyPath:@"name"];
[firstOptionDic setValue:@"0" forKeyPath:@"ids"];
[mainArray addObject:firstOptionDic];
while (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *ids = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 0)];
[cityIDs addObject:ids];
NSString *name = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 1)];
[cityNames addObject:name];
}
sqlite3_finalize(statement);
//sqlite3_close(database);
for (int index = 0; index<cityNames.count; index++) {
NSMutableDictionary *dataAddDic =[[NSMutableDictionary alloc]init];
[dataAddDic setValue:[cityNames objectAtIndex:index] forKeyPath:@"name"];
[dataAddDic setValue:[cityIDs objectAtIndex:index] forKeyPath:@"ids"];
[mainArray addObject:dataAddDic];
}
return mainArray;
}
else
{
NSLog(@"problem");
}
}
return nil;
}
- (NSMutableArray*) getDistrictByCityID:(NSString *) cityID
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:@"select ID,NAME from T_DISTIRICT where CITY_ID=%@ order by NAME",cityID];
const char *query_stmt = [querySQL UTF8String];
NSMutableArray *districtNames = [[NSMutableArray alloc]init];
NSMutableArray *districtIDs = [[NSMutableArray alloc]init];
NSMutableArray *mainArray = [[NSMutableArray alloc]init];
NSMutableDictionary *firstOptionDic =[[NSMutableDictionary alloc] init];
if (sqlite3_prepare_v2(database,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
[firstOptionDic setValue:@"Seçiniz" forKeyPath:@"name"];
[firstOptionDic setValue:@"0" forKeyPath:@"ids"];
[mainArray addObject:firstOptionDic];
while (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *ids = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 0)];
[districtIDs addObject:ids];
NSString *name = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 1)];
[districtNames addObject:name];
}
sqlite3_finalize(statement);
//sqlite3_close(database);
for (int index = 0; index<districtNames.count; index++) {
NSMutableDictionary *dataAddDic =[[NSMutableDictionary alloc]init];
[dataAddDic setValue:[districtNames objectAtIndex:index] forKeyPath:@"name"];
[dataAddDic setValue:[districtIDs objectAtIndex:index] forKeyPath:@"ids"];
[mainArray addObject:dataAddDic];
}
return mainArray;
}
else
{
NSLog(@"problem");
}
}
return nil;
}
-(int)getMerchantByMerchantName:(NSString *)firmID : (NSString *) name
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:@"select ID from T_MERCHANT where NAME like '%%%@' and FIRM_ID=%@ order by NAME",name,firmID];
const char *query_stmt = [querySQL UTF8String];
NSMutableArray *merchantIDs = [[NSMutableArray alloc]init];
if (sqlite3_prepare_v2(database,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
while (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *ids = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 0)];
[merchantIDs addObject:ids];
}
sqlite3_finalize(statement);
//sqlite3_close(database);
if(merchantIDs !=nil)
{
if(merchantIDs.count>0) {
return [[merchantIDs objectAtIndex:0] intValue];
}
else
{
return 0;
}
}
else
{
NSLog(@"problem");
return 0;
}
}
else
{
NSLog(@"problem");
}
}
return 0;
}
- (NSMutableArray*) getMerchantByFirmID:(NSString *)firmID
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:@"select ID,NAME from T_MERCHANT where FIRM_ID=%@ order by NAME",firmID];
const char *query_stmt = [querySQL UTF8String];
NSMutableArray *merchantNames = [[NSMutableArray alloc]init];
NSMutableArray *merchantIDs = [[NSMutableArray alloc]init];
NSMutableArray *mainArray = [[NSMutableArray alloc]init];
NSMutableDictionary *firstOptionDic =[[NSMutableDictionary alloc] init];
if (sqlite3_prepare_v2(database,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
[firstOptionDic setValue:@"Seçiniz" forKeyPath:@"name"];
[firstOptionDic setValue:@"0" forKeyPath:@"ids"];
[mainArray addObject:firstOptionDic];
while (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *ids = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 0)];
[merchantIDs addObject:ids];
NSString *name = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(statement, 1)];
[merchantNames addObject:name];
}
sqlite3_finalize(statement);
//sqlite3_close(database);
if(merchantNames !=nil)
{
for (int index = 0; index<merchantNames.count; index++) {
NSMutableDictionary *dataAddDic =[[NSMutableDictionary alloc]init];
[dataAddDic setValue:[merchantNames objectAtIndex:index] forKeyPath:@"name"];
[dataAddDic setValue:[merchantIDs objectAtIndex:index] forKeyPath:@"ids"];
[mainArray addObject:dataAddDic];
}
if(mainArray.count>0)
{
return mainArray;
}
else
{
return nil;
}
}
else
{
NSLog(@"problem");
return nil;
}
}
else
{
NSLog(@"problem");
}
}
return nil;
}
这就是我调用数据的方式：
NSArray *countries = [[NSArray alloc] initWithArray:[[DBHelper getSharedInstance:[LoggedinUser sharedCenter].dbFileName] getMerchantByFirmID:[LoggedinUser sharedCenter].firmID]];
现在我的问题是，当长时间使用应用程序时，应用程序内存使用量达到140-150mb然后崩溃。当我调试代码时LoggedinUser的dbfilename变为null但在应用程序中没有任何地方我从未将其设置为null。我该怎么做才能改善我的内存管理，或者使用单例类或sqlite数据库使用有什么技巧吗？