I have created a UIView, added the ImageView that UIView as a subview and the add my uiview to navigation controller. here is my code for that:-
UIView* VwTopHdr=[[UIView alloc]initWithFrame:CGRectMake(0,0.3, 1024, 122)];
header_bgimageview =[[UIImageView alloc]initWithFrame:CGRectMake(0,0.3, 1024, 122)];
header_bgimageview.image=[UIImage imageNamed:#"headerBack.png"];
[VwTopHdr addSubview:header_bgimageview];
[header_bgimageview release];
[self.navigationController.view addSubview:VwTopHdr];
Now i want to change the background image of "header_bgimageview" at rune time depending on my code conditions.here i write code to change image:-
header_bgimageview.image=[UIImage imageNamed:#"Differntimage.png"];
But i am not able to change background image using above line of code. What i have to do is removing my UIView from navigation controller create again and the added on navigation controller.
Why i am not able to change image directly instead of creating and added my view again on controller.How can i change image directly?
Expecting for your favourable reply.
Try this, which will basically invalidate the view
[VwTopHdr setNeedsDisplay];
Per class reference documentation on UIView:
setNeedsDisplay
Marks the receiver’s entire bounds rectangle as needing to be redrawn.
- (void)setNeedsDisplay
Related
I have a NSView wrapped in a NSScrollView using the IB. In the initialization function of the view (class is NoteView) containing the NSScrollView, I attempt to add subviews to the NSView as follows:
// Initialize custom view with width 802 and height 130, call it initialSubview
// Set initialSubview's frame origin to (20.0, 580.0). documentView of scrollView
// is size (842.0, 740.0)
// Let innerView be the documentView of the scrollView (I have an IBOutlet attaching
// the scrollView's document view to innerView)
[innerView addSubview:initialSubview];
When I do this, nothing shows up. Likewise, trying this:
[[[scrollView] documentView] addSubview:initialSubview];
doesn't work either. However, if I added it to the contentView:
[[[scrollView] contentView] addSubview:initialSubview];
The subview shows up fine. Any ideas?
As an addendum, if I add something like an NSButton to the documentView in the IB, nothing
shows up as well.
I figured out the issue. It seems NSScrollView and Auto-layout fight themselves.
The solution is to remove whatever you're documentView is (in my case innerView)
from their superview, setTranslatesAutoresizingMaskToConstraints to no, and re-add the view.
The code looks something like this:
[innerView removeFromSuperView];
[innerView setTranslatesAutoresizingMaskIntoConstraints:NO];
[scrollView setDocumentView:innerView];
Then you have to set any constraints you'd like manually
I am pretty sure contentView is the correct place to add it. You may also need to update the content size.
Adding views to a NSScrollView from IB adds the view to the NSScrollView's contentView(NSClipView).
According to your setup you have
NoteView is clip view(contentView) of the NSScrollView.
document view of the scroll view is innerview.
inner view(documentView)'s subview which is initialSubView is added from
-initWithFrame: of contentView.
In an NSScrollView a contentView represents the 'clipped' representation of the documentView.
Having the documentView initialized in init of the contentView is why nothing happens.
Do This
Add NoteView from -awakeFromNib or similar entry point as documentView of the NSScrollView.
Add initialSubView as a subview of NoteView.
I'm working on an iPad app that lets you control different things in a prototype of an intelligent house. For example it lets you turn lights on and off. For this, I have made a UIImageView that shows the floor plan of the house and added UIButtons as subviews for each lamp that can be toggled.
As you can see the buttons are placed perfectly on the floor plan using the setFrame method of each UIButton. However, when I rotate the iPad to portrait orientation, the following happens:
The buttons obviously still have the same origin, however it is not relative to the repositioning of the image.
The floor plan image has the following settings for struts and springs:
and has its content mode set to Aspect Fit.
My question is
how do I dynamically reposition each UIButton, such that it has the same relative position. I figure I have to handle this in the {did/should}AutorotateToInterfaceOrientation delegate method.
It should be noted that the UIImageView is zoomable and to handle this I have implemented the scrollViewDidZoom delegate method as follows:
for (UIView *button in _floorPlanImage.subviews) {
CGRect oldFrame = button.frame;
[button.layer setAnchorPoint:CGPointMake(0.5, 1)];
button.frame = oldFrame;
button.transform = CGAffineTransformMakeScale(1.0/scrollView.zoomScale, 1.0/scrollView.zoomScale);
}
Thank you in advance!
I find the best way to layout subviews is in the - (void) layoutSubviews method. You will have to subclass your UIImageView and override the method.
This method will automatically get called whenever your frame changes and also gets called the first time your view gets presented.
If you put all your layout code in this method, it prevents layout fragmentation and repetition, keeps your view code in your views, and most things just work by default.
I have a UIView that contains another UIView. The outer UIView draws a border around the inner UIView via drawRect. (The border is too complicated to be drawn via CALayer properties.)
At present, when I animate the resizing of the outer UIView, its drawRect method is called once at the beginning of the animation and the result is stretched or shrunk. This does not look good.
I am looking for a way to either redraw the content at every step of the animation, or find a way to achieve the same visual effect. (The result should be similar to the resizing of a stretchable UIImage.)
You should change view's content type to:
your_view.contentMode = UIViewContentModeRedraw;
And it will redraw each time its frame changes.
I ended up adding subviews with autoresizing masks that kept them positioned correctly during the animation.
You need to send a [UIView setNeedsToDisplay] to the view for every time the frame size is changed, you could try overriding the setFrame: method like
- (void)setFrame:(CGRect)r
{
[super setFrame:r];
[self setNeedsToDisplay];
}
UIScrollView is set programmatically, please dont post answers with using .xib file.
My UIScrollView is situated in my model class, so i want the code to be able to be easly imported to another project eg. for iPad or with rotating screen.
I have a view:
self.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width;, self.view.frame.size.height;)];
And my UIScrollView. I want to set it's size to cover all screen not counting all bars that my controller class will have. But i dont know how ;)
I though about subtracting self.view.frame.size.height - self.navigationController.navigationBar.frame.height and self.tabBarController.tabBar.height if each exists.
Is there any method that automatically sets UIScrollView size..?
Thank you in advance!
In your UIViewController subclass, you don't need to worry about the size of any UINavigationController or UITabBarController chrome. Those controllers will automatically resize your controller's main view to fit the appropriate content area.
If I'm creating the UIView myself in the controller's loadView, I usually just initially size it at [[UIScreen mainScreen] applicationFrame]. If I were to add a UIScrollView as a subview that would fill up the entire area of the main view (rather than just using the UIScrollView directly as the main view), I would use self.view.bounds as its frame and be sure to set autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;.
I have a UIImageView in a UIScrollView in another UIScrollView (based on Apple's
PhotoScroller sample code). When the UIScrollView calls back to its controller to dismiss itself, it calls this method:
- (void)dismiss {
[scrollView removeFromSuperview];
ImageScrollView *isv = [self currentImageScrollView];
UIImage *image = isv.imageView;
image.frame = [self.view convertRect:image.frame fromView:isv];
[self.view insertSubview:image belowSubview:captionView];
[(NSObject *)delegate performSelector:#selector(scrollViewDidClose:)
withObject:self
afterDelay:2.0];
}
Now here's the weird part: the image view jumps to a different position right after this method executes, but before the scollViewDidClose method gets called on the delegate. If the image is larger than its new super view, it jumps so that its left edge is aligned with the left edge of its super view. If it's smaller than its new super view, it jumps to the very center of the view. There is no animation to this change.
So my question is, how do I prevent it from doing that? I've tweaked both the super view (self.view) class and the image view class to see what methods might be called. Neither the frame nor the center is set on the image view after this method is called, and while the layoutSubviews method is called on the super view, that is not what jumps the image to the center or left side of the superview. I've also tried turning off autoResizesSubviews in the super view, and setting the autoresizingMask of the image view to UIViewAutoresizingNone, with no change in behavior.
So where is this happening, and why? And more importantly, how do I make it stop?
I've been beating my head on this for days. Any pointers or guidance would be greatly appreciated.
ImageScrollView is the one centering your UIImageView. Set a breakpoint in ImageScrollView layoutSubviews and you'll see how your UIImageView is being centered.
You're taking ImageScrollView's internal imageView and placing it into another view. That's not going to work because ImageScrollView still retains ownership of that UIImageView instance and is still managing its layout.
You'll either need to copy the image into another UIImageView instance, or you'll need to change ImageScrollView to allow it to relinquish ownership of its imageView.
You're not setting up the frame of the 'image' view when you insert it as a subview. You probably want to do that explicitly if you want the view to appear at a particular position in the scroll view.