深入理解iPhone数据持久化(手把手教你iphone开发 – 基础篇)

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- (void)applicationDidFinishLaunching:(UIApplication *)application {
NSString *strOne = @"Persistent data1";
NSString *strTwo = @"Persistent data 2";

NSMutableArray *persistentArray = [[NSMutableArray alloc] init];
[persistentArray addObject:strOne];
[persistentArray addObject:strTwo];

//archive
NSUserDefaults *persistentDefaults = [NSUserDefaults standardUserDefaults];
[persistentDefaults setObject:persistentArray forKey:@"myDefault"];
NSString *descriptionDefault = [persistentDefaults description];
NSLog(@"NSUserDefaults description is :%@",descriptionDefault);

//unarchive
NSArray *UnpersistentArray =
[persistentDefaults objectForKey:@"myDefault"];

NSString *UnstrOne = [UnpersistentArray objectAtIndex:0];
NSString *UnstrTwo = [UnpersistentArray objectAtIndex:1];

NSLog(@"UnstrOne = %@,UnstrTwo = %@",UnstrOne,UnstrTwo);

// Override point for customization after application launch
[window makeKeyAndVisible];
}

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- (void)applicationDidFinishLaunching:(UIApplication *)application {
NSString *strOne = @"Persistent data1";
NSString *strTwo = @"Persistent data 2";

NSArray *persistentArray = [NSArray arrayWithObjects:strOne,strTwo,nil];
NSArray *pathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,    NSAllDomainsMask, YES);

int pathLen = [pathArray count];

NSLog(@"path number is :%d",pathLen);

NSString *filePath;

for(int i = 0; i < pathLen; i++)
{
filePath = [pathArray objectAtIndex:i];
NSLog(@"%d path is :%@",i,filePath);
}

NSString *myFilename = [filePath stringByAppendingPathComponent:@"myFile.rtf"];

NSLog(@"myfile's path is :%@",myFilename);

// no files generated in correspond directory now

[NSKeyedArchiver archiveRootObject:persistentArray toFile:myFilename];
// now the myFile.rtf is generated

// Override point for customization after application launch
[window makeKeyAndVisible];
}

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(void)applicationDidFinishLaunching:(UIApplication *)application {
NSString *myFilename;
// archive
{
NSString *strOne = @"Persistent data1";
NSString *strTwo = @"Persistent data 2";

NSMutableArray *persistentArray = [[NSMutableArray alloc] init];
[persistentArray addObject:strOne];
[persistentArray addObject:strTwo];

NSArray *pathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,    NSAllDomainsMask, YES);

int pathLen = [pathArray count];
NSLog(@"path number is :%d",pathLen);

NSString *filePath;

for(int i = 0; i < pathLen; i++)
{
filePath = [pathArray objectAtIndex:i];

NSLog(@"%d path is :%@",i,filePath);
}

myFilename = [filePath stringByAppendingPathComponent:@"myFile.rtf"];

NSLog(@"myfile's path is :%@",myFilename);

[NSKeyedArchiver archiveRootObject:persistentArray toFile:myFilename];
}

// unarchive
{
NSArray *unarchiveArray = [NSKeyedUnarchiver unarchiveObjectWithFile:myFilename];
NSString *UnstrOne = [unarchiveArray objectAtIndex:0];
NSString *UnstrTwo = [unarchiveArray objectAtIndex:1];

NSLog(@"UnstrOne = %@,UnstrTwo = %@",UnstrOne,UnstrTwo);
}

// Override point for customization after application launch
[window makeKeyAndVisible];
}

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#import <UIKit/UIKit.h>

#include "sqlite3.h"
#define kFileName @"mydb.sql"

@interface PersistentExampleAppDelegate : NSObject <UIApplicationDelegate> {
sqlite3 *database;
UIWindow *window;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;

@end

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(void)applicationDidFinishLaunching:(UIApplication *)application {

NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *paths = [[path objectAtIndex:0] stringByAppendingPathComponent:kFileName];

NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL findFile = [fileManager fileExistsAtPath:paths];

NSLog(@"Database file path = %@",paths);

// 如果找到了数据库文件
if(findFile)
{
NSLog(@"Database file have already existed.");

if(sqlite3_open([paths UTF8String], &database) != SQLITE_OK)//打开数据库失败
{
sqlite3_close(database);
NSAssert(0,@"Failed to open database");
}
}else
{
NSLog(@"Database file does not exsit!");
if(sqlite3_open([paths UTF8String], &database) != SQLITE_OK)//打开数据库失败
{
sqlite3_close(database);
NSAssert(0,@"Failed to open database");
}
}

char *errorMsg;

//创建表
NSString *createSQL = @"create table if not exists fields (row integer primary key, field_data text);";
if(sqlite3_exec(database, [createSQL UTF8String],NULL,NULL,&errorMsg)!=SQLITE_OK)
{
sqlite3_close(database);
NSAssert1(0,@"Error creating table: %s",errorMsg);
}

NSString *strOne = @"Persistent data1";
NSString *strTwo = @"Persistent data 2";

NSMutableArray *persistentArray = [[NSMutableArray alloc] init];
[persistentArray addObject:strOne];
[persistentArray addObject:strTwo];

for (int i = 0; i < [persistentArray count]; i++) {
NSString *upDataSQL = [[NSString alloc] initWithFormat:@"insert or replace into
fields (row,field_data) values (%d,'%@');",i,[persistentArray objectAtIndex:i]];

char* errorMsg;
if(sqlite3_exec(database,[upDataSQL UTF8String],NULL,NULL,&errorMsg)
!= SQLITE_OK)
{
sqlite3_close(database);
NSAssert(0,@"Failed to open database");
}
}

//unarchive
NSString *query = @"select row, field_data from fields order by row";//查找表中的数据
sqlite3_stmt *statement;
if(sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, nil)
== SQLITE_OK)
{
while(sqlite3_step(statement) == SQLITE_ROW)
{
int row = sqlite3_column_int(statement, 0);
char *rowData = (char *)sqlite3_column_text(statement, 1);

NSString *fieldName = [[NSString alloc] initWithFormat:@"show%d",row];
NSString *fieldValue = [[NSString alloc] initWithUTF8String:rowData];

NSLog(@"fieldName is :%@,fieldValue is :%@",fieldName,fieldValue);

[fieldName release];
[fieldValue release];
}
sqlite3_finalize(statement);
}

// Override point for customization after application launch
[window makeKeyAndVisible];
}

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(void)applicationDidFinishLaunching:(UIApplication *)application {

NSString *strOne = @"Persistent data1";
NSString *strTwo = @"Persistent data 2";

NSMutableArray *persistentArray = [[NSMutableArray alloc] init];
[persistentArray addObject:strOne];
[persistentArray addObject:strTwo];

NSArray *filePathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *filePath =
-          [[filePathArray objectAtIndex:0] stringByAppendingPathComponent:@"mydatas.plist"];

[[NSArray arrayWithObjects:persistentArray,nil] writeToFile:filePath atomically:NO];

//load
NSMutableArray *saveDataArray = [[NSMutableArray alloc] init];
if([[NSFileManager defaultManager] fileExistsAtPath:filePath])
saveDataArray = [NSMutableArray arrayWithContentsOfFile:filePath];
else
saveDataArray = [NSMutableArray arrayWithContentsOfFile:[[NSBundle
-                  mainBundle] pathForResource:@"Savedatas" ofType:@"plist"]];
-
NSArray *strArray = [saveDataArray objectAtIndex:0];

NSString *UnstrOne = [strArray objectAtIndex:0];
NSString *UnstrTwo = [strArray objectAtIndex:1];

// Override point for customization after application launch
[window makeKeyAndVisible];
}