Question

我在我的xcode项目中实现了一个SQLite数据库。我想查看从数据库到tableview的所有名称，但收到错误

NSRangeException'，原因：'*** - [__ NSArrayM objectAtIndex：]：index 9223372036854775807超出界限[0 .. 13]'

@interface DisplayViewController ()
@property (nonatomic, strong) DBManager *dbManager;
@property (nonatomic, strong) NSArray *arrPeopleInfo;
  @end

@implementation DisplayViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.mytableview.delegate = self;
    self.mytableview.dataSource = self;
    
    NSString *docsDir;
    NSArray *dirPaths;
    
    
    //Get the directory
    dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    docsDir = dirPaths[0];
     self.dbManager = [[DBManager alloc] initWithDatabaseFilename:@"IApp.db"];    //Build the path to keep the database
   // _databasePath = [[NSString alloc] initWithString:[docsDir stringByAppendingPathComponent:@"IApp.db"]];
   // [self getcount];
    [self loadData];
   // [self getcount];
        // Do any additional setup after loading the view.
}


      
- (void)loadData {
    // Form the query.
    NSString *query = @"select * from iApp";
    
   
    if (self.arrPeopleInfo != nil) {
        self.arrPeopleInfo = nil;
    }
    self.arrPeopleInfo = [[NSArray alloc] initWithArray:[self.dbManager loadDataFromDB:query]];
    
    [self.mytableview reloadData];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    //#warning Potentially incomplete method implementation.
    // Return the number of sections.
    return  1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.arrPeopleInfo.count;
    // return [arri count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"idCellRecord" forIndexPath:indexPath];
    
    NSInteger indexOfname = [self.dbManager.arrColumnNames indexOfObject:@"firstname"];
    NSInteger indexOffname = [self.dbManager.arrColumnNames indexOfObject:@"lastname"];
  
    cell.textLabel.text = [NSString stringWithFormat:@"%@ %@", [[self.arrPeopleInfo objectAtIndex:indexPath.row] objectAtIndex:indexOfname], [[self.arrPeopleInfo objectAtIndex:indexPath.row] objectAtIndex:indexOffname]];
    
    
    return cell;
      
}

Answer 1

当您搜索某个项目时，如果该方法无法找到该项目，Cocoa将返回NSNotFound作为索引。这也适用于-indexOfObject:。 NSNotFound是一个很大的整数（INT_MAX），您可以在Q的标题中看到。

因此

NSInteger indexOfname = [self.dbManager.arrColumnNames indexOfObject:@"firstname"];

如果在接收方中找不到NSNotFound，

将为@"firstName"。请检查您是否有这样的钥匙。错字？骆驼香烟盒？ first N ams？

如果您在编译时不知道密钥，则必须检查它，正如@Inder告诉您的那样：

if(indexOfname==NSNotFound)
  // The object is not present

顺便说一句：你应该重新检查你的命名。它不遵循Cocoa命名约定。

Answer 2

请检查indexOfname或indexOffname是否等于NSNotFound

NSInteger indexOfname = [self.dbManager.arrColumnNames indexOfObject:@"firstname"];
NSInteger indexOffname = [self.dbManager.arrColumnNames indexOfObject:@"lastname"];

if (indexOfname == NSNotFound) {
  //Then don't use this index
}

if (indexOffname == NSNotFound) {
  //Then don't use this index
}

Answer 3

您可以通过非常简单的检查来防止这种情况。

if(indexOfname < [self.dbManager.arrColumnNames count] && indexOffname < [self.dbManager.arrColumnNames count]) {
    cell.textLabel.text = [NSString stringWithFormat:@"%@ %@", [[self.arrPeopleInfo objectAtIndex:indexPath.row] objectAtIndex:indexOfname], [[self.arrPeopleInfo objectAtIndex:indexPath.row] objectAtIndex:indexOffname]];     
}
else {
    cell.textLabel.text = @""; // or what ever you want to do
}

Answer 4

实际上，您已成功获取Database的所有记录。所以左边部分是如何在UITableViewCell中显示的。根据以下代码修改cellForRowAtIndexPath。

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

       UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"idCellRecord" forIndexPath:indexPath];


       cell.textLabel.text = [NSString stringWithFormat:@"%@ %@", [[self.arrPeopleInfo objectAtIndex:indexPath.row] valeuForKey:@"firstname"], [[self.arrPeopleInfo objectAtIndex:indexPath.row] valueForKey:@"lastname"]];


return cell;

}

[__NSArrayM objectAtIndex：]：索引9223372036854775807超出界限[0 .. 13]'

4 个答案: