ios - 如何从iPad启用1920x1080外接显示器？

Question

我试图通过Lightning AV适配器从iPad 4(型号MD513LL / A)设置运行在1920x1080的外接显示器。当我解析每种可用模式时，会看到以下内容:

1600x900

1280x720

1024x768

800x600

640x480

720x480

我已经用三台现代(1-2岁)电视对它进行了测试，并在每个显示器上获得了相同的结果，却从未见过1920x1080。这是我用于外部显示器的代码。

编辑:我发现这只是Lightning数字AV适配器的问题，而不是原始的数字AV适配器。

if ([[UIScreen screens] count] > 1)
{
    UIScreen *secondScreen = [[UIScreen screens] objectAtIndex:1];
    NSString *availableModeString;

    for (int i = 0; i < secondScreen.availableModes.count; i++)
    {
        availableModeString = [NSString stringWithFormat:@"%f, %f",
        ((UIScreenMode *)[secondScreen.availableModes objectAtIndex:i]).size.width,
        ((UIScreenMode *)[secondScreen.availableModes objectAtIndex:i]).size.height];

        [[[UIAlertView alloc] initWithTitle:@"Available Mode" message:availableModeString delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
        availableModeString = nil;
    }

    // undocumented value 3 means no overscan compensation
    secondScreen.overscanCompensation = 3;

    self.secondWindow = [[UIWindow alloc] initWithFrame:CGRectMake(0, 0, 1280, 720)];
    self.secondWindow.backgroundColor = [UIColor blueColor];
    self.secondWindow.screen = secondScreen;

    T9SecondaryScreenViewController *viewController = [[T9SecondaryScreenViewController alloc] initWithNibName:@"T9SecondaryScreenViewController" bundle:nil];
    self.secondWindow.rootViewController = viewController;

    self.secondWindow.hidden = NO;
}

Answer 1

不幸的是，该适配器不能支持1080p。

Source