iPAD 链接外置显示器

-(void)vgadisplay

{

NSLog(@"Number of screens: %d", [[UIScreen screens] count]);

if([[UIScreen screens]count] > 1) //if there are more than 1 screens connected to the device

{

CGSize max;

UIScreenMode *maxScreenMode;

for(int i = 0; i < [[[[UIScreen screens] objectAtIndex:1] availableModes]count]; i++)

{

UIScreenMode *current = [[[[UIScreen screens]objectAtIndex:1]availableModes]objectAtIndex:i];

if(current.size.width > max.width);

{

max = current.size;

maxScreenMode = current;

}

}

//Now we have the highest mode. Turn the external display to use that mode.

UIScreen *external = [[UIScreen screens] objectAtIndex:1];

external.currentMode = maxScreenMode;

UIWindow *newwindow = [[UIWindow alloc] initWithFrame:[external applicationFrame]];

UIView *aview=[[UIView alloc] initWithFrame:[external applicationFrame]];

aview.backgroundColor =[UIColor redColor];

[newwindow addSubview:aview];

newwindow.screen = external;

[newwindow makeKeyAndVisible];

}

}