I have a UIViewController that I'm nesting inside another UIViewController (iOS 4.3+),
it is displayed just fine except one thing - a lot of excessive shadow.
I have tried removing it with setShadowRadius etc, but no luck..
This is the code I use to create it:
RDPreviewViewController* preview = [[[RDPreviewViewController alloc] initWithNibName:#"RDPreviewViewController" bundle:[NSBundle mainBundle]] autorelease];
[preview.view.layer setShadowOpacity:0.0];
[preview.view.layer setShadowRadius:0.0];
[preview.view.layer setColor:nil];
[preview.view setFrame:CGRectMake(0, 100, 320, 264)];
[self.mainView addSubview:preview.view];
And here's the result:
How do I remove it?
I suspect - and this is a theory - that given what you've said that somehow your PNG image with the subtle shadow is being loaded multiple times. This is why your shadow appears much darker than you're expecting - several identical PNGs are being overlaid on top of each other.
The reason I think this is the case is that judging from the code you've posted you're not programatically applying a shadow, and views do not have a shadow by default. Of course, perhaps you are adding a shadow in your code elsewhere, but based on my own experience I think it looks as if somehow the same view (your image view) is getting added multiple times.
It might be helpful if you shared more of your code, if possible.
Related
On my iPhone app, I simply want to set a particular background image, which depends on whether it's an iPhone 5 or not.
So, I tried two approaches:
A) Using
self.view.backgroundColor = [UIColor colorWithPatternImage:backGroundimage];
B) Creating an UIImageView and setting up the image there. Code:
UIImageView *backgroundImageView = [[UIImageView alloc]initWithFrame:screenBounds];
[backgroundImageView setImage:[UIImage imageNamed:backGroundImage]];
[self.view addSubview:backgroundImageView];
But I am having issues with both of them:
Issues with Step A:
When I set the image through that way, I have to deal with the image scaling issues for different sizes of the screen. I use the following code to do the scalling:
UIGraphicsBeginImageContext(screenBounds.size);
[[UIImage imageNamed:backGroundImage] drawInRect:screenBounds];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self.view.backgroundColor = [UIColor colorWithPatternImage:image];
Another issue from Step A is that the image appears quite blurry. It doesn't have the same sharpness to it.
Issues with Step B:
With this, the image looks really crisp and sharp - just the way it should look.
But when I switch to another view using the following code, strangely enough the UIImageView backgroundImageView still appears on the second one. The code I use to switch views is:
[self presentViewController:secondViewController animated:YES completion:nil];
I even tried [backgroundImageView removeFromSuperview], but that doesn't solve anything either.
So what am I doing wrong? And how can I set up a picture as my background which is dependent on the size of the iphone?
Plan B is a good plan. Presenting another view controller should and will definitely hide your image view. If it isn't happening, then it's a problem with the creation of secondViewController, unrelated to the background image on the presenting VC.
Before presenting secondViewController, log it:
NSLog(#"presenting %#", secondViewController);
I'll bet a dollar that it's nil. If I'm right, let's have a look at how you initialize secondViewController. That's the problem, unrelated to the background image view.
Okay, I finally fixed this issue, although the cause of this issue is still puzzling to me.
To fix this, I had to create an IBOutlet property for UIImageView and hook it up on the XIB file.
The reason I was programmatically creating the UIImageView is because the size of the UIImageView depends on what size iPhone they are using. But for the IBOutlet (let's call it as UIImageViewOutlet, I simply used [self.UIImageViewOutlet setFrame:] to get the size and location that I wanted.
I also discovered that one of the buttons that I was programmatically creating, was still visible in the secondViewController. I ended up creating an Outlet on the XIB file for that one as well and used setFrame on it to position it properly.
If anyone who knows the reason of this problem, I will be very grateful.
I am using the standard way of making shadows from a button programmatically, but I would like to shadow to no longer exist after I am done with the button. I could set opacity to 0, but would the shadow still exist and if so would it still tax the system. thanks
this gives an error
tempButton.superview.layer.shadowOffset = nil;
tempButton.superview.layer.shadowRadius = nil;
tempButton.superview.layer.shadowOpacity = nil;
I usually do the following to be safe.
[[tempButton layer] setShadowOpacity:0.0];
[[tempButton layer] setShadowRadius:0.0];
[[tempButton layer] setShadowColor:nil];
Quartz is highly optimized and will not waste any time rendering if it doesn't have to.
I would just remove the button, and replace it with an identical (but non-shadowed) button. Or keep both around and hide/unhide one of them. Sometimes it's easier to create a new UI object than munge around with an existing one.
I have seen many times waiting panels (panels with a uiactivityindicatorview) black/dark with some transparency and white labels.
Like this one :
I guess it is a standard element.
Where can I find it?
Try This. it's the best solution I came across to show the activity. MBProgressHUD
MBProgressHUD looks nice. You might want to check out http://code.google.com/p/toast-notifications-ios/ too.
There's no iOS component that does this.
If you don't want to include an external library just for this one component then you can do it using UI components.
/* Warning, typed from memory */
// Create the UIView that's the background
UIView *pleaseWaitView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 80)];
[pleaseWaitView setBackgroundColor:[UIColor colorWithWhite:0.5 alpha:0.5]];
[[pleaseWaitView layer] setCornerRadius:5.0f];
// And create an activity indicator
UIActivityIndicator *i = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
[i startAnimating];
[pleaseWaitView addSubview:i];
[i release];
// Add it to the main view (in the middle)
[pleaseWaitView setCenter:CGPointMake(self.view.bounds.size.width/2, self.view.bounds.size.height/2)];
[self.view addSubview:pleaseWaitView];
You can add a UILabel with whatever text you want (in your case, 'Authenticating') in the same way as you added the activity indicator.
The tricky part is setting the corner radius - you will probably need this at the top of your .m file :
#import <QuartzCore/QuartzCore.h>
NB You can do this in interface builder as well if you want (apart from the corner radius bit!) ;)
I answered a question that included an overlay like this. I included the code and the overlay image you need to do it with. Take a look at this answer and take a look at the screen shot it created. I use this overlay as I send email in the background so you will want to edit the code to do your function but the overlay code is already in place.
Locking the Fields in MFMailComposeViewController
Happy Coding!
Check out DSActivityView. I've successfully used it in a few of my projects.
As by now there is no standard UIElement for that in iOS.
But checkout this library:
Ok So I have this code, which allows me to put a background image in:
I would love to know how to size this, so on the iPhone 4 I can get a 320x480 size but make it nice with an image of 570.855.
self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"background_stream-570x855.jpg"]];
I have tried this:
UIImageView *image = [[UIImageView alloc]
initWithImage:[UIImage imageNamed:#"background_stream-570x855.jpg"]];
[self.view sendSubviewToBack:streamBG];
image.frame = CGRectMake(0, 0, 320, 480);
Which works, however the problem is it's behind the view, so I can't see it. I could make the view clear, but it has objects on it that need to be displayed.
Any help would be most apretiated
There are multiple options to put Views at desired location.
[self.view sendSubviewToBack:streamBG]; //Sends subview to last position i.e. at the last
[self.view bringSubviewToFront:streamBG] //Brings subview to first position i.e. at the first.
[self.view insertSubview:streamBG atIndex:yourDesiredIndex];//Put at desired index.
This is not answer to your question, though it may help you to set your imageview to desired location.
Hope it helps.
To answer part of your question about sizing. You need to use 2 different images for your app if you want the full resolution of the retina display (iPhone4) You should provide a 320x480 image (i.e. myImage.png) for older iPhones and one at twice the resolution, 640x960, for the iPhone 4. Use the exact same name for the high res version but add an "#2x" to the end (i.e. myImage#2x.png). In your code all you ever have to call is the base name (i.e. myImage.png) the app will choose the correct image based on the hardware its running on. That will get you the best experience on your app.
On the other part about the background view visibility, you could make the background color clear ([UIColor clearColor]) on the view that is blocking it. That would leave the content visible in that view but the view its self would be clear. Alternatively you could just insert the background at a specific index as #Jennis has suggested instead of forcing it to the back.
I have a couple of UIViews with UIImageViews on them. When I display a view the first time, there is a noticeable lag (0.5 second or so) before it is shown. When shown again everything works.
I have managed to work around this by adding all views and then removing them. Like this:
[self performSelectorOnMainThread:#selector(addAndRemoveAllViews)
withObject:nil
waitUntilDone:NO];
The function loops over all views and [addSubview:view] followed by [view removeFromSuperview]. This seems to trigger the images to load while not being shown.
Questions:
This all feels like a workaround to me. Is there a better approach to handle these types of things?
Is it possible to get a callback or something when it's completed? I want to run an animation when done.
Update:
Images are created from NSData like this:
[[UIImageView alloc] initWithImage:[UIImage imageWithData:rawData]];
It seems very likely the image is larger than the image view. If possible shrink it down to the size the image view needs.
The initial delay is loading the image from storage, after that you are using a cached version which is why it is faster.