Understanding Android Activities

Oct 13, 2025 by thesweetdesigns.com 40 views

Introduction

Developing a cross-platform app using Maui can be a great way to reach a wider audience. However, when it comes to Android, things can get a bit tricky, especially when it comes to handling activities and their lifecycles. In this article, we will explore how to get Maui Android SingleTop and SingleTask activities working as documented.

Understanding Android Activities

Before we dive into the solution, let's quickly review how Android activities work. An activity is a single, focused thing that the user can do. For example, an email app might have a compose activity, a list of emails activity, and a view email activity. Each of these activities is a separate instance of the activity class.

SingleTask and SingleTop Activities

In Android, there are two types of activities that are relevant to our discussion: SingleTask and SingleTop.

SingleTask: An activity that is created as a single task. When the user navigates away from the activity, the entire task is removed from the back stack. This means that when the user returns to the activity, it will be recreated from scratch.
SingleTop: An activity that is created as a single top. When the user navigates away from the activity, the topmost instance of the activity is removed from the back stack. When the user returns to the activity, the existing instance is brought back to the top.

Maui Android SingleTask and SingleTop Activities

Now that we have a good understanding of how Android activities work, let's talk about how to create SingleTask and SingleTop activities in Maui.

Creating a SingleTask Activity

To create a SingleTask activity in Maui, you need to add the SingleTask attribute to the activity in your AndroidManifest.xml file.

<activity
    android:name=".MainActivity"
    android:exported="true"
    android:launchMode="singleTask"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

In the above code, we have added the launchMode attribute and set it to singleTask. This tells Android to create the activity as a single task.

Creating a SingleTop Activity

To create a SingleTop activity in Maui, you need to add the SingleTop attribute to the activity in your AndroidManifest.xml file.

<activity
    android:name=".MainActivity"
    android:exported="true"
    android:launchMode="singleTop"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

In the above code, we have added the launchMode attribute and set it to singleTop. This tells Android to create the activity as a single top.

Handling Activity Lifecycles

Now that we have created our SingleTask and SingleTop activities, let's talk about how to handle their lifecycles.

Handling Activity Resume

When the user resumes an activity, the OnResume method is called. This method is where you can put any code that needs to be executed when the activity is resumed.

protected override void OnResume()
{
    base.OnResume();
    // Code to be executed when the activity is resumed
}

Handling Activity Pause

When the user pauses an activity, the OnPause method is called. This method is where you can put any code that needs to be executed when the activity is paused.

protected override void OnPause()
{
    base.OnPause();
    // Code to be executed when the activity is paused
}

Handling Activity Stop

When the user stops an activity, the OnStop method is called. This method is where you can put any code that needs to be executed when the activity is stopped.

protected override void OnStop()
{
    base.OnStop();
    // Code to be executed when the activity is stopped
}

Conclusion

In this article, we have explored how to get Maui Android SingleTop and SingleTask activities working as documented. We have discussed how to create SingleTask and SingleTop activities in Maui, and how to handle their lifecycles. By following the steps outlined in this article, you should be able to create SingleTask and SingleTop activities in Maui that work as documented.

Troubleshooting

If you are experiencing any issues with your SingleTask or SingleTop activities, here are a few things you can try:

Make sure that you have added the SingleTask or SingleTop attribute to the activity in your AndroidManifest.xml file.
Make sure that you have implemented the OnResume, OnPause, and OnStop methods in your activity.
Make sure that you are not using any other launch modes that may be conflicting with the SingleTask or SingleTop launch mode.

Example Use Case

Here is an example use case for SingleTask and SingleTop activities:

Suppose you are developing a file sharing app that allows users to share files with each other. When a user shares a file, the app creates a new activity to display the file. You want the activity to be created as a single task, so that when the user navigates away from the activity, the entire task is removed from the back stack.

In this case, you would create a SingleTask activity in Maui, and add the SingleTask attribute to the activity in your AndroidManifest.xml file. You would also implement the OnResume, OnPause, and OnStop methods in your activity to handle the activity lifecycle.

Code Snippets

Here are some code snippets that demonstrate how to create SingleTask and SingleTop activities in Maui:

// Create a SingleTask activity
[Activity(Label = "SingleTask Activity", LaunchMode = LaunchMode.SingleTask)]
public class SingleTaskActivity : Activity
{
    protected override void OnResume()
    {
        base.OnResume();
        // Code to be executed when the activity is resumed
    }
protected override void OnPause()
{
    base.OnPause();
    // Code to be executed when the activity is paused
}

protected override void OnStop()
{
    base.OnStop();
    // Code to be executed when the activity is stopped
}

}
// Create a SingleTop activity
[Activity(Label = "SingleTop Activity", LaunchMode = LaunchMode.SingleTop)]
public class SingleTopActivity : Activity
{
protected override void OnResume()
{
base.OnResume();
// Code to be executed when the activity is resumed
}
protected override void OnPause()
{
    base.OnPause();
    // Code to be executed when the activity is paused
}

protected override void OnStop()
{
    base.OnStop();
    // Code to be executed when the activity is stopped
}

}

Conclusion

Introduction

In our previous article, we explored how to get Maui Android SingleTop and SingleTask activities working as documented. We discussed how to create SingleTask and SingleTop activities in Maui, and how to handle their lifecycles. In this article, we will answer some frequently asked questions about Maui Android SingleTop and SingleTask activities.

Q: What is the difference between SingleTask and SingleTop activities?

A: The main difference between SingleTask and SingleTop activities is how they handle the back stack. A SingleTask activity is created as a single task, and when the user navigates away from the activity, the entire task is removed from the back stack. A SingleTop activity is created as a single top, and when the user navigates away from the activity, the topmost instance of the activity is removed from the back stack.

Q: How do I create a SingleTask activity in Maui?

A: To create a SingleTask activity in Maui, you need to add the SingleTask attribute to the activity in your AndroidManifest.xml file. You can do this by adding the following code to your AndroidManifest.xml file:

<activity
    android:name=".MainActivity"
    android:exported="true"
    android:launchMode="singleTask"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

Q: How do I create a SingleTop activity in Maui?

A: To create a SingleTop activity in Maui, you need to add the SingleTop attribute to the activity in your AndroidManifest.xml file. You can do this by adding the following code to your AndroidManifest.xml file:

<activity
    android:name=".MainActivity"
    android:exported="true"
    android:launchMode="singleTop"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

Q: How do I handle the activity lifecycle in a SingleTask or SingleTop activity?

A: To handle the activity lifecycle in a SingleTask or SingleTop activity, you need to override the OnResume, OnPause, and OnStop methods in your activity. You can do this by adding the following code to your activity:

protected override void OnResume()
{
    base.OnResume();
    // Code to be executed when the activity is resumed
}
protected override void OnPause()
{
base.OnPause();
// Code to be executed when the activity is paused
}
protected override void OnStop()
{
base.OnStop();
// Code to be executed when the activity is stopped
}

Q: What are some common issues that can occur with SingleTask and SingleTop activities?

A: Some common issues that can occur with SingleTask and SingleTop activities include:

The activity is not being recreated when the user navigates away from it and then returns to it.
The activity is being recreated multiple times when the user navigates away from it and then returns to it.
The activity is not being removed from the back stack when the user navigates away from it.

Q: How can I troubleshoot issues with SingleTask and SingleTop activities?

A: To troubleshoot issues with SingleTask and SingleTop activities, you can try the following:

Check the AndroidManifest.xml file to make sure that the SingleTask or SingleTop attribute is correctly set.
Check the activity lifecycle methods to make sure that they are correctly implemented.
Use the Android Studio debugger to step through the code and see where the issue is occurring.

Q: What are some best practices for using SingleTask and SingleTop activities?

A: Some best practices for using SingleTask and SingleTop activities include:

Use SingleTask activities for activities that need to be recreated when the user navigates away from them and then returns to them.
Use SingleTop activities for activities that need to be recreated when the user navigates away from them and then returns to them, but do not need to be recreated from scratch.
Use the OnResume, OnPause, and OnStop methods to handle the activity lifecycle.
Use the Android Studio debugger to step through the code and see where the issue is occurring.

Conclusion

In this article, we have answered some frequently asked questions about Maui Android SingleTop and SingleTask activities. We have discussed how to create SingleTask and SingleTop activities in Maui, how to handle their lifecycles, and how to troubleshoot common issues. By following the best practices outlined in this article, you should be able to create SingleTask and SingleTop activities in Maui that work as documented.