Platform channels (MethodChannel) in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a MethodChannel with the name 'samples.flutter.dev/battery'.

Flutter

static const platform = MethodChannel('[1]');

Drag options to blanks, or click blank then click option'

Asamples.flutter.battery

Bflutter.dev/battery

Csamples.flutter.dev/battery

Dbattery.flutter.dev

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong or incomplete channel name.

Missing parts of the channel string.

The MethodChannel name must match exactly between Flutter and native code. Here, 'samples.flutter.dev/battery' is the correct channel name.

2fill in blank

medium

Complete the code to invoke the native method 'getBatteryLevel' asynchronously.

Flutter

final int batteryLevel = await platform.[1]('getBatteryLevel');

Drag options to blanks, or click blank then click option'

AexecuteMethod

BsendMethod

CcallMethod

DinvokeMethod

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent method like callMethod.

Forgetting to await the asynchronous call.

The correct method to call native code asynchronously is invokeMethod.

3fill in blank

hard

Fix the error in the code by completing the catch block to handle PlatformException.

Flutter

try {
  final int batteryLevel = await platform.invokeMethod('getBatteryLevel');
} on [1] catch (e) {
  print('Failed to get battery level: $e');
}

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APlatformException

BException

CError

DMethodChannelException

Attempts:

3 left

💡 Hint

Common Mistakes

Catching generic Exception instead of PlatformException.

Using a non-existent exception class.

The native platform errors are caught as PlatformException in Flutter.

4fill in blank

hard

Fill both blanks to send an argument map with key 'charging' and value true to native code.

Flutter

final bool isCharging = await platform.invokeMethod('isCharging', [1]);

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A{'charging': false}

B{'charging': true}

C['charging', true]

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Sending a list instead of a map.

Sending just a boolean without a key.

The argument must be a map with key 'charging' and value true to send data properly.

5fill in blank

hard

Fill all three blanks to define a MethodChannel, invoke 'getBatteryLevel', and handle exceptions properly.

Flutter

static const platform = MethodChannel('[1]');

Future<int> getBatteryLevel() async {
  try {
    final int batteryLevel = await platform.[2]('getBatteryLevel');
    return batteryLevel;
  } on [3] catch (e) {
    return -1;
  }
}

Drag options to blanks, or click blank then click option'

Asamples.flutter.dev/battery

BinvokeMethod

CPlatformException

DcallMethod

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong channel name or method name.

Catching wrong exception type.

Not awaiting the method call.

This code creates a MethodChannel with the correct name, calls the native method asynchronously, and catches PlatformException to handle errors.