Question

我开发了一个应用程序，我需要从数组和数据库中删除行。？在 cellForRowAtIndexPath 中我写的像 cell.textLabel.Text = [myarray.objectAtIndexPath。我希望从数据库和数组中删除该行。在编辑方法中我编写代码如

MoneyAppDelegate *mydelegate=(MoneyAppDelegate *)[[UIApplication sharedApplication]delegate]; if (editingStyle == UITableViewCellEditingStyleDelete) { database *objdata=[[database alloc]init]; [app deleteCategory:objdata]; [self.mytableview deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; }

但它不起作用。在deletecategory方法中，我有像
这样的代码
-(void)deleteCategory:(database *)databaseObj { [databaseObj deleteCategory]; [myarray removeObject:databaseObj]; }

- （UITableViewCell *）tableView：（UITableView *）tableView cellForRowAtIndexPath：（NSIndexPath *）indexPath

{

MoneyAppDelegate * app =（MoneyAppDelegate *）[[UIApplication sharedApplication] delegate];

static NSString * CellIdentifier = @“Cell”;

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator; } cell.textLabel.text = [app.myarray4 objectAtIndex:indexPath.row]; return cell;}

deletecategory是从Database.nothing中删除记录的方法。如何从数据库中删除所选择的行我知道它非常简单，但我提前混淆了..thnanx：）

Answer 1

试试这个 -

- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath
{
 return UITableViewCellEditingStyleDelete;
}

-(void) tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
[self delBtnPressed:indexPath.row];
}

//在这里放置代码 -

-(void)delBtnPressed:(int)sender
 {  
NSString *titleStr=@"";
    NSString *table=@"";
NSString *attribute=@"";

sqlite3 *database;

if(![titleStr isEqualToString:@""])
{
    //-------------------------------deletion-------------------------  

    if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) 
    {

        NSString *  sqlStatement = [NSString stringWithFormat:@"delete from %@ where %@='%@' ",table,attribute,titleStr];

        if (sqlite3_exec(database, [sqlStatement cStringUsingEncoding:NSUTF8StringEncoding], NULL, NULL, NULL)  == SQLITE_OK)
        {

            [yourArr removeAllObjects];
            [self fetchAgain]; //here you need to fetch all records from DB and fill the yourArr again.
            [tblView reloadData];

        }
        sqlite3_close(database);

    }

}
else 
{
    NSLog(@"Error while deleting please try again");
}

}

Answer 2

检查此行..

database *objdata=[[database alloc]init];
[app deleteCategory:objdata];

在第一行中，您只是将“database”的对象创建为“objdata”并将其分配。在此处“objdata”中没有任何内容。因此，当您将此传递给deleteCategory：方法时，数据库中不会删除任何内容。所以这是一个问题。

试试这个：

 database *objdata=[[database alloc]init];
 objdata = [myarray.objectAtIndexPath.row];
[app deleteCategory:objdata];

从数组中删除行＆amp;数据库

2 个答案: