If you want the display dimensions in pixels you can use getSize
:
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
If you're not in an Activity
you can get the default Display
via WINDOW_SERVICE
:
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
If you are in a fragment and want to acomplish this just use Activity.WindowManager (in Xamarin.Android) or getActivity().getWindowManager() (in java).
Before getSize
was introduced (in API level 13), you could use the getWidth
and getHeight
methods that are now deprecated:
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth(); // deprecated
int height = display.getHeight(); // deprecated
For the use case, you're describing, however, a margin/padding in the layout seems more appropriate.
Another way is: DisplayMetrics
A structure describing general information about a display, such as its size, density, and font scaling. To access the DisplayMetrics members, initialize an object like this:
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
We can use widthPixels
to get information for:
"The absolute width of the display in pixels."
Example:
Log.d("ApplicationTagName", "Display width in px is " + metrics.widthPixels);
API level 30 update
final WindowMetrics metrics = windowManager.getCurrentWindowMetrics();
// Gets all excluding insets
final WindowInsets windowInsets = metrics.getWindowInsets();
Insets insets = windowInsets.getInsetsIgnoreVisibility(WindowInsets.Type.navigationBars()
| WindowInsets.Type.displayCutout());
int insetsWidth = insets.right + insets.left;
int insetsHeight = insets.top + insets.bottom;
// Legacy size that Display#getSize reports
final Rect bounds = metrics.getBounds();
final Size legacySize = new Size(bounds.width() - insetsWidth,
bounds.height() - insetsHeight);
You will only need a ScrollView
if the contents you have now do not fit in the iPhone screen. (If you are adding the ScrollView
as the superview of the components just to make the TextField
scroll up when keyboard comes up, then it's not needed.)
The standard way to prevent the TextField
s from being covered by the keyboard is to move the view up/down whenever the keyboard is shown.
Here is some sample code:
#define kOFFSET_FOR_KEYBOARD 80.0
-(void)keyboardWillShow {
// Animate the current view out of the way
if (self.view.frame.origin.y >= 0)
{
[self setViewMovedUp:YES];
}
else if (self.view.frame.origin.y < 0)
{
[self setViewMovedUp:NO];
}
}
-(void)keyboardWillHide {
if (self.view.frame.origin.y >= 0)
{
[self setViewMovedUp:YES];
}
else if (self.view.frame.origin.y < 0)
{
[self setViewMovedUp:NO];
}
}
-(void)textFieldDidBeginEditing:(UITextField *)sender
{
if ([sender isEqual:mailTf])
{
//move the main view, so that the keyboard does not hide it.
if (self.view.frame.origin.y >= 0)
{
[self setViewMovedUp:YES];
}
}
}
//method to move the view up/down whenever the keyboard is shown/dismissed
-(void)setViewMovedUp:(BOOL)movedUp
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.3]; // if you want to slide up the view
CGRect rect = self.view.frame;
if (movedUp)
{
// 1. move the view's origin up so that the text field that will be hidden come above the keyboard
// 2. increase the size of the view so that the area behind the keyboard is covered up.
rect.origin.y -= kOFFSET_FOR_KEYBOARD;
rect.size.height += kOFFSET_FOR_KEYBOARD;
}
else
{
// revert back to the normal state.
rect.origin.y += kOFFSET_FOR_KEYBOARD;
rect.size.height -= kOFFSET_FOR_KEYBOARD;
}
self.view.frame = rect;
[UIView commitAnimations];
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
// register for keyboard notifications
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow)
name:UIKeyboardWillShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillHide)
name:UIKeyboardWillHideNotification
object:nil];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
// unregister for keyboard notifications while not visible.
[[NSNotificationCenter defaultCenter] removeObserver:self
name:UIKeyboardWillShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self
name:UIKeyboardWillHideNotification
object:nil];
}
Best Answer
You can use
CGDisplayScreenSize
to get the physical size of a screen in millimetres. From that you can compute the DPI given that you already know the resolution.So e.g.
That
@"NSScreenNumber"
thing looks dodgy but is the explicit documented means of obtaining aCGDirectDisplayID
from anNSScreen
.