[Xamarin] Error: No xmlns declaration for prefix "local"
I got an error when I built my application. The error said 'No xmlns declaration for prefix "local". Because I used the xaml, I found the compiler did not check the error in xaml file. As a result, it got the runtime error like. This is very easy to solve. Please search all xaml files you used local has this xmlns:local="clr-namespace:[your namespace]"
[Xamarin] Error: AppData\Local\Xamarin\[packages]\[version]\class.jar missing
After I had installed a new component in my Xamarin project, I got an error like that: C:\Users\[username]\ AppData\Local\Xamarin\[packages]\[version]\class.jar missing.
I found the problems are caused the downloading packages are failed before. The Xamarin is not smart enough to re-download automatic.
The solution is simply. I only need to delete all zip files under Error: C:\Users\[username]\AppData\Local\Xamarin\zips and the package folder in the error message. Then I need to rebuild the project. The packages will be download again. The project will build successfully.
[Xamarin] Map not showing in Navigation Page
I am building an app with a map component. I put the Map Control on a navigation page. But I put this code on the button click event.
Code
MapPageXaml page = new MapPage(model); | |
Navigation.PushAsync(page); |
After the button is clicked, nothing happened. No Errors message at all.
I found out the problems is in Key. I need to re-create the key. I need to follow the steps by steps in this page.
Then that is working
Loading Images from Xamarin Forms
Even the UI I built is very simple; I need to load some icons in the UI. I have used navigation page. After I had navigated two pages, then I got an exception, OutOfMemoryException. That is because Bitmap Decode is used a lot of memory. I found we should avoid using:
Code
img.Source = ImageSource.FromFile("test.jpg"); |
We should use the images in the embedded resources
Code
img.Source = ImageSource.FromResource("advgen.test.jpg"); |
Please change the properties of the image file:
Then the problem will solve.
ZXing.Net.Mobile in Xamarin got a black screen
I started to build a library management system for small organisations. This system doesn't require a pc at all. It will works in any iOS and Android devices. It used a camera in the device as a bar scanner. I used an open source framework ZXing.Net.Mobile to do that. I found when I fire the scanner activity, it got a blank back screen. I initialized the framework
Code
MobileBarcodeScanner.Initialize (Application); |
And I gave the camera permission in AndroidManifest.xml, that still got a blank screen.
After I read the document from ZXing.Net.Mobile, it need the flash light. After I gave the flashlight permission, it works.