App Center Crashes

App Center Crashes will automatically generate a crash log every time your app crashes. The log is first written to the device's storage and when the user starts the app again, the crash report will be sent to App Center. Collecting crashes works for both beta and live apps, i.e. those submitted to Google Play. Crash logs contain valuable information for you to help fix the crash.

Please follow the Getting Started section if you haven't set up the SDK in your application yet.

Generate a test crash

App Center Crashes provides you with an API to generate a test crash for easy testing of the SDK. This API can only be used in debug builds and won't do anything in release builds.

Crashes.generateTestCrash();
Crashes.generateTestCrash()

Get more information about a previous crash

App Center Crashes has two APIs that give you more information in case your app has crashed.

Did the app receive a low memory warning in the previous session?

At any time after starting the SDK, you can check if the app received a memory warning in the previous session:

Crashes.hasReceivedMemoryWarningInLastSession();
Crashes.hasReceivedMemoryWarningInLastSession()

This API is asynchronous, you can read more about that in our App Center Asynchronous APIs guide.

Note

This method must only be used after Crashes has been started, it will always return false before start.

Note

In some cases, a device with low memory may not be able to send events.

Did the app crash in the previous session?

At any time after starting the SDK, you can check if the app crashed in the previous launch:

Crashes.hasCrashedInLastSession();
Crashes.hasCrashedInLastSession()

This API is asynchronous, you can read more about that in our App Center Asynchronous APIs guide.

This comes in handy in case you want to adjust the behavior or UI of your app after a crash has occurred. Some developers chose to show additional UI to apologize to their users, or want way to get in touch after a crash has occurred.

Note

This method must only be used after Crashes has been started, it will always return false before start.

Details about the last crash

If your app crashed previously, you can get details about the last crash.

Crashes.getLastSessionCrashReport();
Crashes.getLastSessionCrashReport()

This API is asynchronous, you can read more about that in our App Center Asynchronous APIs guide.

There are numerous use cases for this API, the most common one is people who call this API and implement their custom CrashesListener.

Note

This method must only be used after Crashes has been started, it will always return null before start.

Customize your usage of App Center Crashes

App Center Crashes provides callbacks for developers to perform additional actions before and when sending crash logs to App Center.

To handle the callbacks, you must either implement all methods in the CrashesListener interface, or override the AbstractCrashesListener class and pick only the ones you're interested in.

Use your own CrashesListener

Create your own CrashesListener and assign it like this:

CrashesListener customListener = new CrashesListener() {
    // Implement all callbacks here.
};
Crashes.setListener(customListener);
val customListener = object : CrashesListener {
    // Implement all callbacks here.
}
Crashes.setListener(customListener)

In case you are only interested in customizing some of the callbacks, use the AbstractCrashesListener instead:

AbstractCrashesListener customListener = new AbstractCrashesListener() {
    // Implement any callback here as required.
};
Crashes.setListener(customListener);
val customListener = object : AbstractCrashesListener() {
    // Implement any callback here as required.
}
Crashes.setListener(customListener)

Note

You must set the listener before calling AppCenter.start(), since App Center starts processing crashes immediately after the start.

Should the crash be processed?

Implement this callback if you'd like to decide if a particular crash needs to be processed or not. For example, there could be a system level crash that you'd want to ignore and that you don't want to send to App Center.

@Override
public boolean shouldProcess(ErrorReport report) {
    return true; // return true if the crash report should be processed, otherwise false.
}
override fun shouldProcess(report: ErrorReport?): Boolean {
    return true
}

If user privacy is important to you, you might want to get user confirmation before sending a crash report to App Center. The SDK exposes a callback that tells App Center Crashes to await user confirmation before sending any crash reports.

If you chose to do so, you are responsible for obtaining the user's confirmation, e.g. through a dialog prompt with one of the following options: Always Send, Send, and Don't send. Based on the input, you will tell App Center Crashes what to do and the crash will then be handled accordingly.

Note

The SDK does not display a dialog for this, the app must provide its own UI to ask for user consent.

The following callback shows how to tell the SDK to wait for user confirmation before sending crashes:

@Override
public boolean shouldAwaitUserConfirmation() {

    // Build your own UI to ask for user consent here. SDK does not provide one by default.

    // Return true if you just built a UI for user consent and are waiting for user input on that custom UI, otherwise false.
    return true;
}
override fun shouldAwaitUserConfirmation(): Boolean {
    return true
}

If you return true, your app must obtain (using your own code) the user's permission and message the SDK with the result using the following API:

// Depending on the user's choice, call Crashes.notifyUserConfirmation() with the right value.
Crashes.notifyUserConfirmation(Crashes.DONT_SEND);
Crashes.notifyUserConfirmation(Crashes.SEND);
Crashes.notifyUserConfirmation(Crashes.ALWAYS_SEND);
Crashes.notifyUserConfirmation(Crashes.DONT_SEND)
Crashes.notifyUserConfirmation(Crashes.SEND)
Crashes.notifyUserConfirmation(Crashes.ALWAYS_SEND)

As an example you can refer to our custom dialog example.

Get information about the sending status for a crash log

At times, you would like to know the status of your app crash. A common use case is that you might want to show UI that tells the users that your app is submitting a crash report, or, in case your app is crashing very quickly after the launch, you want to adjust the behavior of the app to make sure the crash logs can be submitted. App Center Crashes has three different callbacks that you can use in your app to be notified of what is going on:

The following callback will be invoked before the SDK sends a crash log

@Override
public void onBeforeSending(ErrorReport errorReport) {
    // Your code, e.g. to present a custom UI.
}
override fun onBeforeSending(report: ErrorReport?) {
    // Your code, e.g. to present a custom UI.
}

The following callback will be invoked after the SDK sent a crash log successfully

@Override
public void onSendingSucceeded(ErrorReport report) {
    // Your code, e.g. to hide the custom UI.
}
override fun onSendingSucceeded(report: ErrorReport?) {
    // Your code, e.g. to hide the custom UI.
}

The following callback will be invoked if the SDK failed to send a crash log

@Override
public void onSendingFailed(ErrorReport report, Exception e) {
    // Your code goes here.
}
override fun onSendingFailed(report: ErrorReport?, e: Exception?) {
    // Your code goes here.
}

Add attachments to a crash report

You can add one binary and one text attachment to a crash report. The SDK will send it along with the crash so that you can see it in App Center portal. The following callback will be invoked right before sending the stored crash from previous application launches. It will not be invoked when the crash happens. Here is an example of how to attach text and an image to a crash:

@Override
public Iterable<ErrorAttachmentLog> getErrorAttachments(ErrorReport report) {

    // Attach some text.
    ErrorAttachmentLog textLog = ErrorAttachmentLog.attachmentWithText("This is a text attachment.", "text.txt");

    // Attach binary data.
    byte[] binaryData = getYourBinary();
    ErrorAttachmentLog binaryLog = ErrorAttachmentLog.attachmentWithBinary(binaryData, "your_filename.jpeg", "image/jpeg");

    // Return attachments as list.
    return Arrays.asList(textLog, binaryLog);
}
override fun getErrorAttachments(report: ErrorReport?): MutableIterable<ErrorAttachmentLog> {

    // Attach some text.
    val textLog = ErrorAttachmentLog.attachmentWithText("This is a text attachment.", "text.txt")

    // Attach binary data.
    val binaryData = getYourBinary()
    val binaryLog = ErrorAttachmentLog.attachmentWithBinary(binaryData, "your_filename.jpeg", "image/jpeg")

    // Return attachments as list.
    return listOf(textLog, binaryLog)
}

Note

The size limit is currently 7 MB. Attempting to send a larger attachment will trigger an error.

Enable or disable App Center Crashes at runtime

You can enable and disable App Center Crashes at runtime. If you disable it, the SDK will not do any crash reporting for the app.

Crashes.setEnabled(false);
Crashes.setEnabled(false)

To enable App Center Crashes again, use the same API but pass true as a parameter.

Crashes.setEnabled(true);
Crashes.setEnabled(true)

The state is persisted in the device's storage across application launches.

This API is asynchronous, you can read more about that in our App Center Asynchronous APIs guide.

Note

This method must only be used after Crashes has been started.

Check if App Center Crashes is enabled

You can also check if App Center Crashes is enabled or not:

Crashes.isEnabled();
Crashes.isEnabled()

This API is asynchronous, you can read more about that in our App Center Asynchronous APIs guide.

Note

This method must only be used after Crashes has been started, it will always return false before start.

Handled Errors

App Center also allows you to track errors by using handled exceptions. In order to do so, simply use the trackException method:

try {
    // your code goes here.
} catch (Exception exception) {
    Crashes.trackException(exception);
}
try {
    // your code goes here.
} catch (exception: Exception) {
    Crashes.trackException(exception)
}

An app can optionally attach properties to a handled error report to provide further context. Pass the properties as a map of key/value pairs (strings only) as shown in the example below.

try {
    // your code goes here.
} catch (Exception exception) {
    Map<String, String> properties = new HashMap<String, String>() {{
        put("Category", "Music");
        put("Wifi", "On");
    }};
    Crashes.trackError(exception, properties, null);
}
try {
    // your code goes here.
} catch (exception: Exception) {
    val properties = mapOf("Category" to "Music", "Wifi" to "On")
    Crashes.trackError(exception, properties, null)
}

You can optionally add one binary and one text attachment to a handled error report. Pass the attachments as an Iterable as shown in the example below.

try {
    // your code goes here.
} catch (Exception exception) {

    // Attach some text.
    ErrorAttachmentLog textLog = ErrorAttachmentLog.attachmentWithText("This is a text attachment.", "text.txt");

    // Attach binary data.
    byte[] binaryData = getYourBinary();
    ErrorAttachmentLog binaryLog = ErrorAttachmentLog.attachmentWithBinary(binaryData, "your_filename.jpeg", "image/jpeg");

    // Track an exception with attachments.
    Crashes.trackException(exception, null, Arrays.asList(textLog, binaryLog));
}
try {
    // your code goes here.
} catch (exception: Exception) {

    // Attach some text.
    val textLog = ErrorAttachmentLog.attachmentWithText("This is a text attachment.", "text.txt")

    // Attach binary data.
    val binaryData = getYourBinary()
    val binaryLog = ErrorAttachmentLog.attachmentWithBinary(binaryData, "your_filename.jpeg", "image/jpeg")

    // Track an exception with attachments.
    Crashes.trackException(exception, null, listOf(textLog, binaryLog))
}

Reporting NDK crashes

Reporting crashes

To receive proper crash reports in App Center, first make sure you have the App Center Crashes SDK set up by following the instructions listed above.

Building the breakpad library

Next, you must include and compile Google Breakpad by following the instructions listed in the official Google Breakpad for Android README.

Note

The App Center SDK does not bundle Google Breakpad by default.

Attaching the exception handler

Once you have Google Breakpad included, attach the NDK Crash Handler after AppCenter.start:

// Attach NDK Crash Handler after SDK is initialized.
Crashes.getMinidumpDirectory().thenAccept(new AppCenterConsumer<String>() {
    @Override
    public void accept(String path) {

        // Path is null when Crashes is disabled.
        if (path != null) {
            setupNativeCrashesListener(path);
        }
    }
});

The method setupNativeCrashesListener is a native method that you must implement in C/C++:

#include "google-breakpad/src/client/linux/handler/exception_handler.h"
#include "google-breakpad/src/client/linux/handler/minidump_descriptor.h"

void Java_com_microsoft_your_package_YourActivity_setupNativeCrashesListener(
        JNIEnv *env, jobject, jstring path) {
    const char *dumpPath = (char *) env->GetStringUTFChars(path, NULL);
    google_breakpad::MinidumpDescriptor descriptor(dumpPath);
    new google_breakpad::ExceptionHandler(descriptor, NULL, dumpCallback, NULL, true, -1);
    env->ReleaseStringUTFChars(path, dumpPath);
}

Where dumpCallback is used for troubleshooting:

/*
 * Triggered automatically after an attempt to write a minidump file to the breakpad folder.
 */
bool dumpCallback(const google_breakpad::MinidumpDescriptor &descriptor,
                  void *context,
                  bool succeeded) {

    // Allow system to log the native stack trace.
    __android_log_print(ANDROID_LOG_INFO, "YourLogTag",
                        "Wrote breakpad minidump at %s succeeded=%d\n", descriptor.path(),
                        succeeded);
    return false;
}

Once these methods are properly set up, the app sends the minidump to App Center automatically upon restart. To troubleshoot, you can use verbose logs (AppCenter.setLogLevel(Log.VERBOSE) before AppCenter.start) to check if minidumps are sent after the app is restarted.

Note

The app sends the minidump file as a binary attachment to App Center. Since App Center allows only one binary attachment, you can send only text attachments with the native crash report.

Note

There is a known bug in breakpad which makes it impossible to capture crashes on x86 emulators.

Symbolication

See the Diagnostics documentation for more information regarding the processing of crashes.