JonDouglas

Approaching a Xamarin.Android Bindings Case

1. Investigation

One of the best ways to investigate a problematic Xamarin.Android Binding is to first ensure you have the proper tooling available:

• Diagnostic MSBuild Output Enabled(Instructions)
• Java Decompiler(http://jd.benow.ca/)
• .NET Decompiler(https://www.jetbrains.com/decompiler/)
• Binding SDK Documentation

JonDouglas

Xamarin.Android Performance Issues

1. Investigation

One of the best ways to investigate a problematic Xamarin.Android Errors is to first ensure you have the proper tooling available:

• Diagnostic MSBuild Output Enabled(Instructions)
• Android SDK Installed
• Android API Level Documentation

JonDouglas

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Mirror
{
    public class Program
    {
        public static void Main(string[] args)

JonDouglas

Xamarin.Android Support Library NuGet m2repository manual download

1. Investigation

You may run into issues with downloading the m2repository when referencing a NuGet package of the Android Support Libraries / Google Play Services.

Example error:

`Download failed. Please download https://dl-ssl.google.com/android/repository/android_m2repository_r25.zip

JonDouglas

using System;

using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;

using LoginScreen;

JonDouglas

Diagnosing JIT / AOT Timings

1. After installing the .apk, open up an Android Device Monitor to the Logcat tab, or use adb logcat
2. Look for a log under ActivityManager that has the message Displayed Activity: <timing>

EX:

07-28 12:48:38.356: I/ActivityManager(769): Displayed com.myapplication.App1/md58adf3f2592a7497b73592b5e766304c2.MainActivity: +1s990ms

JonDouglas

using System;
using MonoTouch.UIKit;
using System.Threading.Tasks;
using System.Threading;
using System.Text;
using MonoTouch.Foundation;

namespace Demo2LongRunningTasks
{
	partial class LongRunningTaskViewController : UIViewController

JonDouglas

Xamarin.Android Installing APK as System Application

Ideally if you took a Release .apk, anything in the lib/ABI should go into the respective /system/lib folder.

For example with a File->New Android Project

If I created a Release Aligned .apk, I should be able to extract it and view the following:

lib\armeabi-v7a

JonDouglas

Thread uiThread;

uiThread = Thread.CurrentThread; //Ensure this is called during a Main/UI thread call

void WhatThreadAmI([CallerMemberName] string method = "", [CallerLineNumber] int line = 0)
{
    Console.WriteLine("=========================");
    Console.WriteLine("=========================");
    Console.WriteLine("=========================");
    Console.WriteLine($"{method} - {line}" {IsMainThread}");

JonDouglas

Code Name	Version	API Level	Release Date
None	1.0	1	2008-09-23
None	1.1	2	2009-02-09
Cupcake	1.5	3	2009-04-27
Donut	1.6	4	2009-09-15
Eclair	2.0-2.1	5-7	2009-10-26
Froyo	2.2-2.2.3	8	2010-05-20
Gingerbread	2.3-2.3.7	9-10	2010-12-06
Honeycomb	3.0-3.2.6	11-13	2011-02-22