I am developing an Android app in xamarin in which I require to create a QR code from the data input by the user in various fields.
SO my question is can I do it with the help of Xamarin? If yes then please help me with any sample code or tutorial link.
ZXing.Net has a QR code generator built in. Take a look at that.
Something like this could do the job (following code not tested):
var writer = new BarcodeWriter
{
Format = BarcodeFormat.QR_CODE,
Options = new EncodingOptions
{
Height = 200,
Width = 600
}
};
var bitmap = writer.Write("My content");
This should generate an image with the QR code. There are loads of other options you can mess with.
ZXing is also available as a component for Xamarin.Android, Xamarin.iOS and Windows Phone
Related
I downloaded the sample Сamera2 API code to my device. In another app, I want to launch a third-party camera, but I can't select the one I downloaded.
I Found solution for Xamarin.Android. I added above my CameraActivity page right near that Manifest String
[Activity (Label = "Camera2Basic", MainLauncher = true, Icon = "#drawable/icon")]
my Intent Filter which contains this code
[IntentFilter(new[] { "android.media.action.IMAGE_CAPTURE" },
Categories = new[] { Intent.CategoryDefault})]
This code write strings in Manifest, they needs for default intent call
Anyone got a tip how to add a View over the current view (modal)? I'm creating an app with a video recorder, and the video screen is presented modally on the screen. I want some text to show up above the video modal, and I think I've tried any approach I can think of atm.
Currently im stuck with something like:
var topMost = frameModule.topmost();
var View = new ViewModule.View(questionHolder);
topMost.currentPage._addView(View, 0);
But with no success. questionHolder is a view I fetch with
currentpage.getViewById
Edit:
From the answer of #davecoffin where I understood you could not mix native views and nativescripts views, I was able to solve this in my case by accessing the native view directly and adding a subview to it. In my case:
var sharedApplication = utils.ios.getter(UIApplication, UIApplication.sharedApplication);
var overlay = UIView.alloc().initWithFrame({
origin : {
x: 0,
y: 44,
},
size: {
height: 100,
width: platform.screen.mainScreen.widthPixels
}
});
overlay.backgroundColor = UIColor.blackColor;
overlay.alpha = .6;
sharedApplication.keyWindow.rootViewController.presentedViewController.cameraOverlayView = overlay;
You can directly create and use modal pages as described in this article.
If I am understanding your approach correctly...
You cant add Nativescript views on top of native views.
Check out this forum question: https://discourse.nativescript.org/t/appending-nativescript-views-to-a-native-ui-view/1412
Basically once you have appended a native view (not a nativescript layout or ui view), then every view you append after that must be a native view. For iOS you use addSubview, not sure about android atm.
Currently I was working on a UWP application. I captured the ink strokes into an image. Now the same image need to display as a preview. So the original image need to re-size to shorter size or thumbnail need to be generated.
I tried with using the larger image directly as a source to shorter sized image canvas --> not working (visible image quality degrade)
I also used Transcode of image programatically --> same result as above
I test with the same image. Re-sized the same image using paint, and there interestingly the quality of the re-sized image remains good.
Please help me to solve the issue I faced.
I not sure, need to see some code, but could be how you are saving the image? Here an example:
try
{
Windows.Storage.Pickers.FileSavePicker save = new Windows.Storage.Pickers.FileSavePicker();
save.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.Desktop;
save.DefaultFileExtension = “.png”;
save.FileTypeChoices.Add(“PNG”, new string[] { “.png” });
StorageFile filesave = await save.PickSaveFileAsync();
using (IOutputStream fileStream = await filesave.OpenAsync(FileAccessMode.ReadWrite))
{
if (fileStream != null)
{
await m_InkManager.SaveAsync(fileStream);
}
}
}
catch (Exception ex)
{
var dialog = new MessageDialog(ex.Message);
dialog.ShowAsync();
}
I will post a great tutorial of Can Bilgin that explain perfectly all about inking.
Drawing / Inking API in WinRT (C#) – I
Drawing / Inking API in WinRT (C#) – II
Drawing / Inking API in WinRT (C#) – III
i'm developing an app based on maps.
Here my problem is i'm not able to display user location on maps. but i can able to displaying the map's using Xamarin.Forms.
Here is my Code
var map = new Map(
MapSpan.FromCenterAndRadius(
new Position(17.3660, 78.4760), Distance.FromMiles(0.3)))
{
IsShowingUser = true,
HeightRequest = 100,
WidthRequest = 960,
VerticalOptions = LayoutOptions.FillAndExpand
};
var stack = new StackLayout { Spacing = 0 };
stack.Children.Add(map);
Content = stack;
My out put
here i want to display the user current location.
this entire code was return in Xamarin Shared code.
i'm not using Xamarin Android.
can any one help me to solve this problem.
Thanks in advance.
Most platforms require you to request permission to get a users location via GPS.
For Android this is located in the Android Manifest (under project properties). Check both ACCESS_FINE_LOCATION and ACCESS_COURSE_LOCATION.
It's a known bug on Android. It's working fine on iOS.
Here's the link to the bug report on bugzilla.
A possible workaround would be to show a map pin instead for as long as the bug hasn't been fixed. It goes like this:
map.Pins.Add(new Pin { Label = "You are here",
Position = new Position(17.3660, 78.4760) });
UPDATE: This issue has been fixed on Xamarin.Forms.Maps version 1.3.0.6292.
The problem is that I am opening workflow designer dynamically from one shell application and I don't have reference to Canvas. I am able to save the WF4 as image but the image is not getting saved properly and contains left & top margins. I followed many articles to get it working but no success. I referred to following article as well.
Saving a canvas to png C# wpf
I am using the below function. I don't have any reference to canvas.
private BitmapFrame CreateWorkflowImage()
{
const double DPI = 96.0;
Visual areaToSave = ((DesignerView)VisualTreeHelper.GetChild(this.wd.View,
0)).RootDesigner;
Rect bounds = VisualTreeHelper.GetDescendantBounds(areaToSave);
RenderTargetBitmap bitmap = new RenderTargetBitmap((int)bounds.Width,
(int)bounds.Height, DPI, DPI, PixelFormats.Default);
bitmap.Render(areaToSave);
return BitmapFrame.Create(bitmap);
}
Please help on this.
I am able to resolve the issue by referring to again the following link
Saving a canvas to png C# wpf
I got the reference to canvas by using following code
Visual canvas= ((DesignerView)VisualTreeHelper.GetChild(this.WorkflowDesigner1.View, 0)).RootDesigner;
This has resolved the border/margin issue.
Please have a look here: http://blogs.msdn.com/b/flow/archive/2011/08/16/how-to-save-wf4-workflow-definition-to-image-using-code.aspx
let’s look at how to generate an image of the workflow definition using the standard mechanism of WPF. After all, workflow designer canvas is a WPF control.
BitmapFrame CreateWorkflowDefinitionImage()
{
const double DPI = 96.0;
// this is the designer area we want to save
Visual areaToSave = ((DesignerView)VisualTreeHelper.GetChild(
this.workflowDesigner.View, 0)).RootDesigner;
// get the size of the targeting area
Rect size = VisualTreeHelper.GetDescendantBounds(areaToSave);
RenderTargetBitmap bitmap = new RenderTargetBitmap((int)size.Width, (int)size.Height,
DPI, DPI, PixelFormats.Pbgra32);
bitmap.Render(areaToSave);
return BitmapFrame.Create(bitmap);
}
The above C# method is very straightforward. Just get the workflow diagram part of the workflow designer and create an in-memory image of it using some WPF API. The next thing is simple: create a file and save the image.
void SaveImageToFile(string fileName, BitmapFrame image)
{
using (FileStream fs = new FileStream(fileName, FileMode.Create))
{
BitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(image));
encoder.Save(fs);
fs.Close();
}
}
At last, let’s try to invoke the above 2 methods in the OnInitialized() method to hook it up and then close the application.
protected override void OnInitialized(EventArgs e)
{
// ...
this.SaveImageToFile("test.jpg", this.CreateWorkflowDefinitionImage());
Application.Current.Shutdown();
}