Image in a Drawer not loaded immediately - image

I have an image saved in a dedicated directory in my flutter project. The entire directory is included as asset in pubspec.yaml, the code where it is shown is this:
Drawer(
child: ListView(
children: <Widget>[
Image(image: AssetImage('immagini/liberty_square.jpg')),
SizedBox(height: 4),
ListTile(
// contents
),
// etc...
],
),
);
Drawer is located in a StatefulWidget. The image weighs about 2MB. It's a photo of a square in a town. I haven't used DrawerHeader to avoid paddings and margins.
In the android simulator (android studio), the image is loaded immediately as I open the Drawer, instead in my two real devices I have problems.
At app start I open the Drawer, but I can't see the image. Sometimes I have to wait some seconds to see the image, but other times I have to close and re-open the Drawer many times to see the image.
This happens both in test mode (android studio) and in production mode (apk installed and opened, without a pc).
I have thought to pre-load, but the image is an asset, not downloaded from network.

Try using precached image to load the image before the drawer is built.
Go to the widget that contains your drawer and add this to your initState:
precacheImage(new AssetImage('immagini/liberty_square.jpg'));
Then just call your image the same way you do now.

Related

Xamarin.iOS: Adding image in visual studio assets.xcassets imageset for both landscape and portrait orienatation

For my Xamarin.iOS project I am using LaunchScreen.Storynboard for showing launch screen. For adding images, I am using asset catalog. My application supports both orientations on iPad. However, when I open imageset in visual studio it shows only one #2x image for iPad which will be occupied by Portrait image. Now, for adding landscape image I have edited its Contents.Json file and added image details there. added image locally and also added its entry in projects .csproject file.
However, when I build and run application its only picking one image and applying it to both the orientations.
e.g. Its picking landscape image and applying it in both landscape and portrait launch screen image. Now, in portrait mode image is showing vertically stretched.
which is causing UI issue.
How to set image for both the orientations in visual studio xcassets imageset?
Any suggestion would be appreciated.
Thank You.
How to set image for both the orientations in visual studio xcassets
imageset?
LaunchImage ImageSet is the old way which has been deprecated, we don't need to set storyboard or xib on Launch Screen, but it is nothing except image. We can't find a way to set LaunchImage ImageSet in the latest Visual-Studio.
Refer: Xcode 11 UILaunchImages has been deprecated, use launch storyboards instead Warning
Now, in portrait mode image is showing vertically stretched. which is
causing UI issue.
You should use auto-layout to layout your image in both landscape and portrait orientation so that it won't be stretched. See document here: Managing Launch Screens with Storyboards
:

Nativescript launch screen logo tiny

I used the new Nativescript Sidekick feature to create my launch screens, but the logo appears tiny on the screen. To fix it to make it look more like the stock nativescript logo size, I manually modified and replaced the logo in App Resources files generated to more closely match those images, but regardless my logo continues to look very small on the launch screen. Where is that sizing controlled? If I look in splash_screen.xml I don't see anything that controls the size for android.

Launch Image does not show up in my iOS App

I want to get a simple launch screen to show in my app, built using Xcode 6.0.1.
I have added a launch screen in two ways: As an XIB (with the default name, LaunchScreen.xib) and as a launchimage set within xcassets.
I have made sure that my "Launch Screen File" is set to LaunchScreen.xib.
I have simulated every device available (e.g., "iPhone5 iOS8" / "iPhone5s iOS8" / "iPhone6 iOS8". Note that only iOS 8 is available within the simulator).
So this has been quite painful for something that should be trivial. Here is what I did:
Use xcassets
I decided to use .xcassets versus the .xib for launch. I deleted the .xib. If you have images.xcassets already in your project then great, otherwise you can add one from File>New>file:
Create a Launch Image Set
Now create at a minimum a launchimage set and icon set in your .xcassets file by right clicking in the navigator area.
Update the App Icons and Launch Images Settings
Then I made sure that the "Apps icon and image sets" in my target are as below.
Very Important: Make sure the "Launch screen file" setting is blank.
Add the Images
Last but not least, the terminology used by Apple for the device selection is confusing. Initially I thought that since I am deploying for iOS8 only (iPhone Portrait), I can do this and just put in the iPhone 6 and iPhone 6+ launch images:
I quickly realized that is not the way this works and I was getting a warning:
"An iPhone Retina (4-inch) launch image for iOS 7.0 and later is required."
So I had to select the iPhone under iOS 7.0 and later as well and add an Image for the iPhone 5s.
So to find out which boxes to check on the right, do not ask the question: What is my minimum iOS and device and device orientation but rather ask:
What devices out there can support my minimum iOS? Now What is the minimum iOS supported on those devices? And make sure you check all of those boxes. So for me, I am targeting iPhone 5s, 6 and 6 Plus at 8.0 but given that iPhone 5s can exist with 7.0, I need to check the 7.0 box as well to show the image placeholder. In other words, the (iOS) check box on the right shows you the minimum iOS version available for that device and you need to click it to show the image placeholder and put an image regardless of whether you are deploying at this iOS version or not.
The LaunchScreen.xib and the info value Launch screen interface file base name are from my experience both placeholders that are created when the project is created. If you would like to use the Images.xcassets exclusively for your launch screens, delete both the LaunchScreen.xib and the info.plist item.
If you provide the info.plist setting you app will use the xib and not your Images.xcassets
Xcode 8:
Images used in LaunchScreen.xib should not be on a .xcassets, try dropping them in the bundle.
Looks like that by the time that the .xib gets loaded, the images in the .xcassets are not yet available.
EDIT: For some opaque reason after adding some localizations, launch screen stopped working, now it works with an image from the assets, extremely weird.
My solution was to create all the launch images.
Then I set the Launch Images Source to the LaunchImage asset, and leave launch screen file blank.
Finally if the project does not have a Launch Screen.xib, then add that file and leave it as is.
For me, it worked when I uninstalled the app and then restarted the simulator.
When installed again, launch image appeared as expected.
This also worked on an actual device.
For the people who are using the Asset Catalog's Launch Image, as I learned this the hardest way, I had this scenario where I was first given a jpg file then I asked them convert it to PNG.
I trusted them enough that I scoured the internet first as to why the launch image wasn't showing and did every solution to no avail, then I tried putting back the old launch image and was working fine, it was there that I thought what I have is not a proper PNG file.
TL;DR: Make sure that you are actually using a proper PNG file, not a file with a renamed extension.
Removing "Launch screen interface file base name" from Info.plist file AND trashing "Launch Screen.xib" worked for me.
Simply removing and reinstalling the app worked for me:
Testing in the Simulator
Delete the app in the simulator.
Quit and restart the simulator.
Run the project again in Xcode.
Testing on Device
Delete the app from the device.
Run the project again in Xcode.
The problem with the accepted answer is that if you don't set the Launch Screen File, your application will be in upscaling mode on devices such as the iPhone 6 & 6+ => blurry rendering.
Below is what I did to have a complete working solution (I'm targeting iOS 7.1 & using Xcode 8) on every device (truly, I was getting crazy about this upscaling problem)
1. Prepare your .xcassets
To simplify it, I'm using a vector .PDF file. It is very convenient and avoid creating multiple images for each resolution (1x, 2x, 3x...). I also assume here you already created your xcassets.
Add your launch screen image (or vector file) to your project
Go to your .xcassets and create a New Image Set. In the Attributes window of the Image, select Scales -> Single Scale
Drag and drop the vector file in the Image Set.
2. Create your Launch Screen file
3. Add your image to your Launch Screen file
Add an Image View object to your Launch Screen file (delete the labels that were automatically created). This image view should refer to the previous .xcassets Image Set. You can refer it from the Name attribute. At this stage, you should correctly see your launch screen image in your image view.
Add constraints to this image view to keep aspect ratio depending on the screen resolution.
4. Add your Launch Screen file to your target
Fianlly, in your Target General properties, refer the Launch Screen file.
Start your app, and your splash screen should be displayed. Try also on iPhone6 & iPhone6+, and your application should be correctly displayed without any upscaling (the Launch Screen file aims to do this).
After several hours frustrated on this, I decided to use this way. It works for both iPhone and iPad (on Xcode 6.1)
File >> New File >> User Interface >> Launch Screen
Create new key/value: "Launch screen interface file base name"/"Your Launch Screen Name" in YourApp-Info.plist
1 picture worths more than thousand words. Please look at below:
I've read about a bug in Xcode 6 which prevents landscape only apps from displaying a launch image.
Try to set images and orientation within Images.xcassets:
There is a bug where Xcode 6 launch images stored in asset files cause iphone landscape only apps on iOS7/iOS8 to display a black launch image. iPad works fine.
http://www.raywenderlich.com/forums/viewtopic.php?f=2&t=10868
Solution:
Use the new Launchscreen.xib for ios8+ onwards. (it is far better)
For ios7 devices to work you simply turn off launch images source and use the old school launch images file names in the plist
iphone5 - Default-568h#2x.png
iphone4s - Default#2x.png
ipad2 - Default-Landscape~ipad.png
ipad retina - Default-Landscape#2x~ipad.png
Painful but works.
B
I have tried everything but solution was extremely simple. Just use .jpg file instead of .png on your LaunchScreen.storyboard. It seems like iOS does not render .png file or relatively big image size at launch screen.
Do what Spectravideo328 answered and:
Try to UNCHECK the iOS 7 and later box and CHECK the iOS 6 and prior box in the asset catalog. There seems to be a bug with the iOS 7 Launch Image.
(These both have the same Launch Images except for the 320x480 one)
Hope this helps, it did help for me!
I set up "LaunchImage" in my asset catalog and simply cleared the "Launch Screen" field et voila ! I had the launch images appear ...
One way is to also add "Launch Screen" (LaunchScreen.xib), paste the image into UIImageView and then set it to "Horizontal Center in Container" and "Vertical Center in Container" in "Align" if you are using Auto Layout.
Screen:
http://i.stack.imgur.com/CfnHT.png
Don't forget to put LaunchScreen.xib into "Launch Screen File".
I had the same issue after I started using Xcode 6.1 and changed my launcher images. I had all images in an Asset Catalog.
I would get only a black screen instead of the expected static image. After trying so many things, I realised the problem was that the Asset Catalog had the Project 'Target Membership' ticked-off in its FileInspector view. Ticking it to ON did the magic and the image started to appear on App launch.
Make sure your images are accurate size according to Apple guidelines.
Make sure, You will select only one option , either launch screen file or Launch Image Source. You can find these two options in Project build settings -> General
My suggestion to you is to select Launch Image Source as Image.Assets. Create splash image assets there in Image.assests folder.
Reference image for right configuration:
If you have changed your launch image from a previous image, and observe the following:
devices/simulators where the app was previously installed, still show the previous image and refuse to show the new one (uninstalling and reinstalling the app doesn't help)
devices/simulators where the app was not previously installed, show the new launch image
It is likely because of the caching of launch image done by iOS. Rebooting the device should solve the problem.
I tried opening a new project, and moving through the same steps you did to set a launch screen.
By default, the .xib was set as "Launch Screen File," and the white screen with a label did show for half a second in the simulator.
I then a "Launch Images Source" and set it to the Images.xcassets which generated with the background images I added to the project. (all good so far)
Rerun the simulator and the launch images don't show...
After deleting the specified "Launch Screen File" and a clean: Product -> Clean, from the top menu, the launch images finally show up.
Maybe that will help?
There is a file 'LaunchScreen.xib' automatically added to your project
Deleting this will shift xCode to using your Default images in Images.xcassets
edited to add
go to App Icons and Launch Images
Launch Screen File should be blank/emtpy
I had a very strange bug. Apparently my launch image source was only set for debug configuration and not release. This resulted in my launch screen appearing when running debug configuration, but when I changed to release I just got a black screen.
I fixed this when I changed my build configuration to release the Launch Image Source button appeared and I had to choose Use Asset Catalog again.
For those who are curious, this is what my project.pbxproj looked like.
...
...
...
XXXXXXXXXXXXXXXXXXXXXXXX /* Release */ = {
isa = XCBuildConfiguration;
buildSettings = {
ALWAYS_SEARCH_USER_PATHS = NO;
ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
ASSETCATALOG_COMPILER_LAUNCHIMAGE_NAME = LaunchImage; <---THIS LINE WAS MISSING
...
...
...
For some reason, I had to change the asset catalog location to "relative to project" for this to work.
I had also deleted the app from my phone and reinstalled, but it was probably the "relative to project" that did it.
* (Xcode 7.2 / Deployment Target 7.0 / Landscape Orientation Only) *
I know is an old question but with Xcode 7.2 I'm still getting the message and I fixed with this:
1) Select PORTRAIT and both landscapes. Add "Launch Images Source" and "Launch Screen File"
2) In your Launch Image select iPhone "8.0 and Later" and "7.0 and Later".
3) Add this code in your appDelegate:
#if __IPHONE_OS_VERSION_MAX_ALLOWED < 90000
- (NSUInteger)supportedInterfaceOrientations
{
return UIInterfaceOrientationMaskLandscape;
}
#else
- (UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window
{
return (UIInterfaceOrientationMaskLandscape);
}
#endif
4) Add this on your ViewController
#if __IPHONE_OS_VERSION_MAX_ALLOWED < 90000
- (NSUInteger)supportedInterfaceOrientations
#else
- (UIInterfaceOrientationMask)supportedInterfaceOrientations
#endif
{
return UIInterfaceOrientationMaskLandscape;
}
I hope help to somebody else.
This is worked for me. Click LaunchScreen.storyboard then in the right panel you can select "Is Initial View Controller" check box.
LaunchScreen.storyboard -> Is Initial View Controller
I just figured this out. My launch image was not showing up, I get a white screen when launching on a device (iPhone 6, 7+) or testFlight. Fix: Renamed "Landing_screen.png" to just "Landing_screen" removing .png part. The image icon in Xcode changed to white icon and in the launch screen storyboard the image appears as a question mark now. The Launch image now appears and not the white screen. My Setup: I am using Swift 3.1 with Xcode 8.3.1. In LaunchScreen.storyboard I added a simple image view and stretched the image to fit the view controller. I set auto layout constraints Top/Bottom/Leading/Trailing space to superview to 0.
I encountered this bug also with my landscape-only app. Following carlodurso's solution works:
tick the "Landscape" box
drag and drop the image to the place.
For me, it works when I remove LaunchScreen.xib and change it to a storyboard file LaunchScreen.storyboard.

Xcode landscape launch image warning when not required

I am finishing up an app which only runs in portrait mode on the iPad and iPhone. As a result, I don't provide any landscape launch images - I could include them, but they would never be seen, so I'd prefer to save the space in my app.
How do I stop XCode trying to auto assign 'Default.png' and 'Default#2x.png' into the landscape images for the iPad? This causes a warning to appear, since these images are for the iPhone and so are the wrong dimensions. Alternatively, a solution to suppress the warning that appears would suffice.
Control-click on an unwanted iPad launch image in the Summary window and choose Delete. This will remove the reference to the image as a launch image for iPad. Even better, go ahead and include solid black PNG images for the unneeded launch images. They will be compressed by Xcode when it builds your app, so that they will take up virtually no space in the app bundle.
I regard the fact that Xcode automatically creates default launch images for iPhone but not iPad as a bug. I suggest you complain about this behavior at bugreporter.apple.com.
EDIT: Just to be clear, what you want is a minimal set of properly sized images with the following names:
Default.png
Default#2x.png
Default-568h#2x.png
Default-Portrait~ipad.png
Default-Landscape~ipad.png
Default-Portrait#2x~ipad.png
Default-Landscape#2x~ipad.png
This will prevent Xcode from using e.g. an iPhone launch image in an iPad slot.

how to change the default background image when info button is selected

Im running Xcode 4.3.2 I have built a basic iPad/iphone app. On the main menu the info button is displayed. When I select it on my device the screen flips over and displays some info. My question is, When the screen flips over, for a brief second, you can see an image in the background. Although it's an image in my project folder I'm not quite sure how to change it or how it got there. Thanks
-Anthony
This image is actually the MainWindow_ipad.xib or MainWindow_iphone.xib file within my project. you can drag and drop a new image into it from your media library once you've put that image into your project folder and then selected xcode>file>add files to "your project's name"

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