按下按钮并有一个随机的viewcontroller？

Question

我非常擅长使用Xcode在Objective-C中进行编码，而且我试图能够按下按钮并让代码拉出一个随机视图控制器。

我为每个视图控制器创建了类并分配了它们。

我的viewcontroller.m：

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

-(IBAction)randomviewbutton {

    int randomview = rand() % 9;
    switch (randomview) {
        case 0:
            change.modalViewController = [UIViewController class:@"ViewController1"];
            break;
        case 1:
            change.modalViewController = [UIViewController class:@"ViewController2"];
            break;
        case 2:
            change.modalViewController = [UIViewController class:@"ViewController3"];
            break;
        case 3:
            change.modalViewController = [UIViewController class:@"ViewController4"];
            break;
        case 4:
            change.modalViewController = [UIViewController class:@"ViewController5"];
            break;
        case 5:
            change.modalViewController = [UIViewController class:@"ViewController6"];
            break;
        case 6:
            change.modalViewController = [UIViewController class:@"ViewController7"];
            break;
        case 7:
            change.modalViewController = [UIViewController class:@"ViewController8"];
            break;
        case 8:
            change.modalViewController = [UIViewController class:@"ViewController9"];
            break;
        default:
            break;
    }
}

我的viewcontroller.h：

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController {

    IBOutlet UIViewController *change;
}

-(IBAction)randomviewbutton;

@end

Answer 1

您必须使用-presentViewController:animated:completion:呈现模态视图控制器，而不是直接更改modalViewController属性。

这样的事情：

-(IBAction)randomviewbutton {
    UIViewController *vc = nil;
    int randomview = rand() % 9;
    switch (randomview) {
        case 0:
            vc = [[ViewController1 alloc] init];
        case 1:
            vc = [[ViewController2 alloc] init];
        default:
            break;
    }
    [change presentViewController:vc animated:YES completion:nil];
}