I am developing an universal app where I have given a background image for a UIView using the following code.
UIImageView *imgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"backImage.png"];
[self.view addSubview:imgView];
[self.view sendSubviewToBack:imgView];
I have created the following images and added to the project,
backImage.png
backImage#2x.png
backImage-Portrait~ipad.png
backImage-Portrait#2x~ipad.png
backImage-Landscape~ipad.png
backImage-Landscape#2x~ipad.png
But it does not seem to take the correct images.
It works fine when I run the app on iphone (I mean it takes the backImage.png and backImage#2x.png accordingly) but when I run the app on ipad it does not use the ipad images, it still uses the iphone images.
Can anyone please tell what must be going wrong.
Thanks in advance.
You need to detect in your code what type of device is being used, and depending on that, choose the appropriate image.
See here: iOS detect if user is on an iPad
I may be wrong, but I don’t think UIImage will know whether to load the ‘portrait' or ‘landscape' version of an image, much less change them dynamically when you rotate your interface. I think you’re expecting a lot more magic then there is.
Those conventions work in the app launch snapshot, but I think that’s the extent of it?
Related
I'm building an app where I need to take a screenshot of a view whose subviews are camera sessions (AVFoundation sessions). I've tried this code:
CGRect rect = [self.containerView bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[self.containerView.layer renderInContext:context];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Which effectively gets me an UIImage with the views, only that the camera sessions are black:
I've tried the private method UIGetScreenImage() and works perfectly, but as Apple doesn't allows this, I can't use it. I've also tried the one in Apple's docs but it's the same. I've tracked the problem to AVFoundation sessions using layers. How can I achieve this? The app has a container view with two views which are stopped camera sessions.
If using iOS 7, it's fairly simple and you could do something like this from a UIViewController:
UIView *snapshotView = [self.view snapshotViewAfterScreenUpdates:YES];
You can also use this link from a widow: iOS: what's the fastest, most performant way to make a screenshot programatically?
For iOS 6 and earlier, I could only find the following Apple Technical Q&A: [How do I take a screenshot of my app that contains both UIKit and Camera elements?]
Capture the contents of your camera view.
Draw that captured camera content yourself into the graphics context that you are rendering your UIKit elements. (Similar to what you did in your code)
I too am currently looking for a solution to this problem!
I am currently out at the moment so I can't test what I have found, but take a look at these links:
Screenshots-A Legal Way To Get Screenshots
seems like its on the right track - here is the
Example Project (and here is the initial post)
When I manage to get it to work I will definitely update this answer!
My application developed for iPad contains two UiWebView's, and executes this code to make sure the content fits nicely on the screen:
- (void)webViewDidFinishLoad:(UIWebView *)webView {
[ipadWebMonth1 stringByEvaluatingJavaScriptFromString:#"document.body.style.zoom = 1.7;"];
[ipadWebMonth2 stringByEvaluatingJavaScriptFromString:#"document.body.style.zoom = 1.7;"];
}
Theres no way of me testing as I don't own one but as the screen size of the iPad mini is smaller, (I understand the amount of pixels are the same).
But surely this code would zoom the content in too much making some of in unable to be seen as I have user interaction disabled.
What options do I have here? Is there some sort of simulator I can download? Or is there a way of detecting the iPad mini and making a new function with different code?
Thanks,
Jack.
Try calling this in your viewDidLoad method (also make sure to remove your JavaScript code):
[_webView setScalesPageToFit:YES]
It makes the webpage scaled to fit exactly the webview's bounds.
One of the ways to improve user experience in iOS while showing images is to download them asynchronously without blocking the main thread and showing them....
But I want to add something to this -
Initially when there is no image,show a spinner while the async download has started.
After the download cache the image on local iOS disk for later use.
After the download populate the image part of UIImageView.
And dont just plonk the image into view for user. Showly Fade in the user (i.e. from alpha 0.0 to 1.0)
I have been using SDWebImage for sometime now. It works well but does not satisfy my 1st requirement (about spinner) and 4th.
Is there any help out there to satisfy all this?
Three20 http://www.three20.info has a TTImageView class that statisfies 2-3, you can subclass it and overwrite setImage: and create the fade animation there. (or just modify TTImageView.m directly).
Spinner is easy as well when you modify TTImageView you can add a TTActivityView on top and remove it on setImage:
I am fairly new in iOS programming and I am creating my first app.
I have been trying to use the following code to change the navigation bar background image (this is using the new iOS 5 method):
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:#"gradientBackgroundPlain.png"] forBarMetrics: UIBarMetricsDefault];
It works fine, but my image is 640 x 88 and it looks too big for the bar. It's like the system doesn't want to scale it, or do I need to do it manually? If I scale the image and create a smaller one it looks pixelated in the retina display.
Any thoughts on this?
Any help or response will be appreciated.
Thanks,
Jorge.-
Your image gradientBackgroundPlain.png should be 320x44, and create a second image named gradientBackgroundPlain#2x.png with a size of 640x88. Include the #2x image in your bundle, but continue to specify gradientBackgroundPlain.png for the name of the image. The platform automatically chooses the correct size image for use depending on whether there is a retina display present or not.
What's the best way to use a UISlider to change the volume of the iPhone in an app?
I've tried using that Bill (Using a UISlider to change volume)
But nothing appears on the screen using the code:
MPVolumeView *volumeView = [[[MPVolumeView alloc] initWithFrame:
CGRectMake(0, 0, 215, 22)] autorelease];
volumeView.center = CGPointMake(150,375);
[volumeView sizeToFit];
[self.view addSubview:volumeView];
I've just found a very easy way. Instead of coding, just place it in your XIB.
Open the XIB where you want to place to slider into
Add a UIView to your view
Change the class identity from UIView to MPVolumeView
Change backgroundColor to clear
Voila!
PS: Tested it on a device with iPhone OS 3.0. As lostInTransit stated before, it won't work on the simulator.
Using a UISlider to change volume
^ I tried that lostintransit, however this is not changing the ringer volume. It comes up on the iphone screen, but doesn't change anything. Even using the demo project provided.
I am using this same technique, however I am noticing the following behavior:
On an iPod touch G2:
The MPVolumeView slider works and fully responds to the rocker switch from app startup time.
On an iPhone Gen 1 and 3G:
The MPVolumeView slider doesn't start changing the volume until media playback has occurred via the AudioQueue APIs, and will stop changing the volume when AudioSessionSetActive(false) is called. Even more bizarre: if you hit the rocker switch on the iPhone while using the AudioQueue APIs during playback then the MPVolumeView slider will work for the rest of the lifetime of the app.
This code keeps everything in sync, and tends to help with ensuring that the rocker switch and the slider stay in sync, but it doesn't eliminate the issues I am having with MPVolumeView on an iPhone.
All of my experience here is under iPhone OS 3.0 with the iPhone 3.0 SDK.
I hope this helps narrow down your problem somewhat.
My next tactic was to start doing things with kAudioSessionProperty_AudioRoute and try alternate values for kAudioSessionProperty_AudioCategory to see what happens.
Side note:
Thanks to everyone on the IB techniques for creation and managing the MPVolumeView. I was using code to create and place it, and I keep forgetting about the technique where you can set the type of the UIView in IB.
Side note 2:
In working with the MPVolumeView I discovered that if you set the audio category to anything other than kAudioSessionCategory_MediaPlayback that the MPVolumeView will display the text "iPhone..." when the iPhone is set to silent mode.
Use an MPVolumeView to display a slider that allows the user to modify the system volume.
If you want to be able to change the iPhone volume, MPVolumeView is the only option. Try the example on this link.
http://www.stormyprods.com/blogger/2008/09/proper-usage-of-mpvolumeview-class.html