Question

好的，首先我必须说我在iOS领域有点像菜鸟。那说我会进一步解释我的问题。

我正在制作一个用户获取动物列表的应用程序。当用户从列表中选择动物时 - ＆gt;第二个viewcontroller打开，imageview必须设置为选定的动物+有动物的描述。

将这段代码放在viewController2.m的ViewDidLoad中

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self.navigationItem setTitle:@"Animal"];   //here the title has to be set to the animal but I will try this later

   // Do any additional setup after loading the view from its nib.
    UIImage * cowImage = [UIImage imageNamed:@"cow.png"];
    UIImage * horseImage = [UIImage imageNamed:@"horse.png"];

    ViewController1 *viewController1 = [[ViewController1 alloc]init];

    characterNumber = viewController1.pickedRow;

    //set the uiimageview based on characternumber
    switch (characterNumber) {
        case 0:
            foto.image = pukkelpopImage;
            detailInfo.text = @"blabla";
            [self.navigationItem setTitle:characterName];
            break;
        case 1:
            foto.image = cactusImage;
            break;
        default:
            break;
    }

}

在我的ViewController 1.m中，我有这个方法来选择一个项目。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{


    ViewController2 *ViewController22 = [[ViewController2 alloc] initWithNibName:@"ViewController2" bundle:nil];

    [[self navigationController] pushViewController:ViewController22 animated:YES];

    pickedRow = indexPath.row;   //As you can see here I try to get which row was tapped


}

问题出在哪里？感谢您阅读

Answer 1

您正在viewController2中分配一个新的viewController1实例，该实例与推送viewController2的viewController1实例完全无关。

尝试在viewController2中声明一个NSInteger属性来存储拾取的行，并在将它推入didSelectRowAtIndexPath之前设置viewController2实例的值。

在ViewController2.h中声明属性：

@property (nonatomic) NSInteger pickedRow;

在ViewController1.m didSelectRowAtIndexPath中，在初始化viewController2实例之后设置属性，然后再推送它：

viewController2.pickedRow = indexPath.row;

无需在ViewController2.m中初始化viewController1：

// ViewController1 *viewController1 = [[ViewController1 alloc]init];

变量characterNumber可以用self.pickedRow替换。

根据第一个viewcontrollerios中选择的行更改第二个viewcontroller中的信息

1 个答案: