我几乎完成了这个项目。我使用 SQLite 创建了一个电话簿的小型应用程序。成功构建后我面临线程错误。总而言之,我会告诉你我在这个项目中的最新进展。我创建了一个简单的电话簿,您可以在其中添加该人的姓名、号码和地址。有两个按钮可以保存和查找联系人。所有状态都打印在标签上。我已将 libsqlite3.dylib 包含并导入到项目中。一旦构建完成。我在主类中遇到一个线程错误,说明 libc++abi.dylib:终止调用抛出异常。
有什么帮助吗?我几乎完成了这个项目。
我的 viewcontroller.h 看起来像这样:
#import <UIKit/UIKit.h>
#import <sqlite3.h>
@interface ViewController : UIViewController
@property (strong, nonatomic) IBOutlet UITextField *name;
@property (strong, nonatomic) IBOutlet UITextField *address;
@property (strong, nonatomic) IBOutlet UITextField *phone;
@property (strong, nonatomic) IBOutlet UILabel *status;
- (IBAction)saveData:(id)sender;
- (IBAction)findContact:(id)sender;
@property (strong, nonatomic) NSString *databasePath;
@property (nonatomic) sqlite3 *contactDB;
@end
我的 viewcontroller.m 看起来像这样:
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
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:
@"contacts.db"]];
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: _databasePath ] == NO)
{
const char *dbpath = [_databasePath UTF8String];
if (sqlite3_open(dbpath, &_contactDB) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt =
"CREATE TABLE IF NOT EXISTS CONTACTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, ADDRESS TEXT, PHONE TEXT)";
if (sqlite3_exec(_contactDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
{
_status.text = @"Failed to create table";
}
sqlite3_close(_contactDB);
}
else
{
_status.text = @"Failed to open/create database";
}
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)saveData:(id)sender
{
sqlite3_stmt *statement;
const char *dbpath = [_databasePath UTF8String];
if (sqlite3_open(dbpath, &_contactDB) == SQLITE_OK)
{
NSString *insertSQL = [NSString stringWithFormat:
@"INSERT INTO CONTACTS (name, address, phone) VALUES (\"%@\", \"%@\", \"%@\")",
self.name.text, self.address.text, self.phone.text];
const char *insert_stmt = [insertSQL UTF8String];
sqlite3_prepare_v2(_contactDB, insert_stmt,
-1, &statement, NULL);
if (sqlite3_step(statement) == SQLITE_DONE)
{
self.status.text = @"Contact added";
self.name.text = @"";
self.address.text = @"";
self.phone.text = @"";
}
else
{
self.status.text = @"Failed to add contact";
}
sqlite3_finalize(statement);
sqlite3_close(_contactDB);
}
}
- (IBAction)findContact:(id)sender
{
const char *dbpath = [_databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &_contactDB) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:
@"SELECT address, phone FROM contacts WHERE name=\"%@\"",
_name.text];
const char *query_stmt = [querySQL UTF8String];
if (sqlite3_prepare_v2(_contactDB,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
if (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *addressField = [[NSString alloc]
initWithUTF8String:
(const char *) sqlite3_column_text(
statement, 0)];
_address.text = addressField;
NSString *phoneField = [[NSString alloc]
initWithUTF8String:(const char *)
sqlite3_column_text(statement, 1)];
_phone.text = phoneField;
_status.text = @"Match found";
}
else
{
_status.text = @"Match not found";
_address.text = @"";
_phone.text = @"";
}
sqlite3_finalize(statement);
}
sqlite3_close(_contactDB);
}
}
@end