Question

我正在为iPhone开发一款应用。我有一个模型类数据库，它具有所有sqlite查询方法，如login，register和importAllInboxArticles。对于登录，我有LoginViewController，用于寄存器 - RegisterViewController。我可以在这些类中成功定义Database * db对象，并在ViewDidLoad中成功调用login或register方法。所以，这很好。

但是，我正在使用ArticleViewController实现相同的逻辑：UITableViewController，它应该调用方法importAllInboxArticles，形成NSMutable数组，然后显示所有内容

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {...}

所以我在ViewDidLoad中调用importAllInboxArticles，但是importAllInboxArticles中的NSLog（）语句都没有打印出来。我也尝试在cellForRowAtIndexPath中调用importAllInboxArticles，但没有结果。

Database.m

- (NSMutableArray*)importAllInboxArticles:(int)user_id
{

    NSLog(@"Start,Article Importing");

    NSMutableArray *inboxArticles = [[NSMutableArray alloc]initWithCapacity:20];
    NSString *sql = [NSString stringWithFormat:@"SELECT * FROM Article AS A JOIN UserArticle AS UA ON UA.article_id=A.id WHERE user_id=?"];
    sqlite3_stmt *select;

    int result = sqlite3_prepare_v2(self.db, [sql UTF8String], -1, &select, NULL);

    if (result == SQLITE_OK) {
        sqlite3_bind_int (select, 3, (NSInteger)user_id);

        NSLog(@"Article Importing SQL: %d, SQLITE_ROW: %d", result, SQLITE_ROW);

        while (sqlite3_step(select) == SQLITE_ROW) {
            NSLog(@"In Article Import While");
            NSMutableArray *values = [[NSMutableArray alloc] initWithCapacity:6];

            // add the id:
            [values addObject:
             [NSString stringWithFormat:@"%s", sqlite3_column_text(select, 0)]];
            // add the title:
            [values addObject:
             [NSString stringWithFormat:@"%s", sqlite3_column_text(select, 1)]];
            // add the content:
            [values addObject:
             [NSString stringWithFormat:@"%s", sqlite3_column_text(select, 2)]];
            // add the author:
            [values addObject:
             [NSString stringWithFormat:@"%s", sqlite3_column_text(select, 3)]];
            // add the date:
            [values addObject:
             [NSString stringWithFormat:@"%s", sqlite3_column_text(select, 4)]];
            // add the tags:
            [values addObject:
             [NSString stringWithFormat:@"%s", sqlite3_column_text(select, 5)]];



            Article* article = [[Article alloc]init];
            article.article_id = [[values objectAtIndex:0]integerValue];
            article.title = [values objectAtIndex:1];
            article.content = [values objectAtIndex:2];
            article.author = [values objectAtIndex:3];
            article.date = [values objectAtIndex:4];
            article.url = [values objectAtIndex:5];
            article.tags = [values objectAtIndex:6];
            [inboxArticles addObject:article];
            NSLog(@"Article added.");

            NSLog(@"Sucsefful loginnnn! %@", [NSString stringWithFormat:@"%s", sqlite3_column_text(select, 1)] );


        }

    }
    NSLog(@"%d articles were imported form db", inboxArticles.count);
    return inboxArticles;
}

ArticleViewController.m

   //
//  ArticleViewController.m
//  ReadLater
//
//  Created by Ibragim Gapuraev on 09/06/2014.
//  Copyright (c) 2014 Sermilion. All rights reserved.
//

#import "ArticleViewController.h"
#import "LoginViewController.h"

@interface ArticleViewController ()

@end

@implementation ArticleViewController

@synthesize db,articles;


//- (id)init{
//    self = [super init];
//    if (!self) {
//        self.db = [Database init];
//        self.articles = [[NSMutableArray alloc]init];
//    }
//    return self;
//}

- (NSMutableArray* ) articles
{
    if (!articles) {
        articles = [[NSMutableArray alloc] initWithCapacity:20];
    }

    return articles;
}

- (Database* ) db
{
    if (!db) {
        db = [[Database alloc] init];
    }
    return db;
}


//- (id)initWithStyle:(UITableViewStyle)style
//{
//    self = [super initWithStyle:style];
//    if (self) {
//        
//    }
//    return self;
//}

- (void)setInboxList:(NSMutableArray* )inboxList
{
    self.articles = inboxList;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.articles = [self.db importAllInboxArticles:16];
    NSLog(@"Number of articles in inboxArticles %d", articles.count);
    // Do any additional setup after loading the view.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    return self.articles.count;
}

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



    NSLog(@"Number of articles in articles %d", self.articles.count);
    static NSString *CellIdentifier = @"Content";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    NSInteger rowIndex = indexPath.row;

    // Configure the cell...
    Article* article = [self.articles objectAtIndex:rowIndex];
    NSString *listingKey = article.title;
    //NSString *listingKey = [[[MAIN_CONTROLLER partsCatalog].listing allKeys] objectAtIndex:indexPath.row];
    NSString *listingValues = article.url;
    cell.textLabel.text = listingKey;
    cell.detailTextLabel.text = listingValues ;

    return cell;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}





@end

那么，为什么我不能像在其他视图中一样调用ArticleViewController中的方法？谢谢。

Answer 1

我想指出您可能需要考虑使用常规UIViewController并将数据源和委托函数放在（a）单独的文件中。否则你的ViewController将变得非常混乱。最佳做法是在所有情况下都避免使用UITableViewController。

如果未调用viewDidLoad，则未正确加载ViewController。您的问题不在您的代码中。如果是，它还应该调用您的数据库方法。您的UITableView如何知道要显示多少个单元格？这是UITableViewController的.m文件的完整列表吗？

如果是这样，您错过了所需的最低实施功能：https://developer.apple.com/library/ios/documentation/uikit/reference/UITableViewDataSource_Protocol/Reference/Reference.html#//apple_ref/occ/intfm/UITableViewDataSource/tableView:numberOfRowsInSection：

在ViewController iOS中调用模型方法

1 个答案: