Interface BinaryMessenger
- All Known Implementing Classes:
DartExecutor
,FlutterNativeView
,FlutterView
BinaryMessenger
is expected to be utilized from a single thread throughout the
duration of its existence. If created on the main thread, then all invocations should take place
on the main thread. If created on a background thread, then all invocations should take place on
that background thread.
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Nested Class Summary
Modifier and TypeInterfaceDescriptionstatic interface
Handler for incoming binary messages from Flutter.static interface
Binary message reply callback.static interface
An abstraction over the threading policy used to invoke message handlers.static class
Options that control how a TaskQueue should operate and be created. -
Method Summary
Modifier and TypeMethodDescriptiondefault void
Disables the ability to queue messages received from Dart.default void
Enables the ability to queue messages received from Dart.default BinaryMessenger.TaskQueue
Creates a TaskQueue that executes the tasks serially on a background thread.default BinaryMessenger.TaskQueue
Creates a TaskQueue that executes the tasks serially on a background thread.void
send
(String channel, ByteBuffer message) Sends a binary message to the Flutter application.void
send
(String channel, ByteBuffer message, BinaryMessenger.BinaryReply callback) Sends a binary message to the Flutter application, optionally expecting a reply.void
setMessageHandler
(String channel, BinaryMessenger.BinaryMessageHandler handler) Registers a handler to be invoked when the Flutter application sends a message to its host platform.default void
setMessageHandler
(String channel, BinaryMessenger.BinaryMessageHandler handler, BinaryMessenger.TaskQueue taskQueue) Registers a handler to be invoked when the Flutter application sends a message to its host platform.
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Method Details
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makeBackgroundTaskQueue
Creates a TaskQueue that executes the tasks serially on a background thread.There is no guarantee that the tasks will execute on the same thread, just that execution is serial. This is could be problematic if your code relies on ThreadLocal storage or introspection about what thread is actually executing.
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makeBackgroundTaskQueue
@UiThread default BinaryMessenger.TaskQueue makeBackgroundTaskQueue(BinaryMessenger.TaskQueueOptions options) Creates a TaskQueue that executes the tasks serially on a background thread.BinaryMessenger.TaskQueueOptions
can be used to configure the task queue to execute tasks concurrently. Doing so can be more performant, though users need to ensure that the task handlers are thread-safe. -
send
Sends a binary message to the Flutter application.- Parameters:
channel
- the nameString
of the logical channel used for the message.message
- the message payload, a direct-allocatedByteBuffer
with the message bytes between position zero and current position, or null.
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send
@UiThread void send(@NonNull String channel, @Nullable ByteBuffer message, @Nullable BinaryMessenger.BinaryReply callback) Sends a binary message to the Flutter application, optionally expecting a reply.Any uncaught exception thrown by the reply callback will be caught and logged.
- Parameters:
channel
- the nameString
of the logical channel used for the message.message
- the message payload, a direct-allocatedByteBuffer
with the message bytes between position zero and current position, or null.callback
- aBinaryMessenger.BinaryReply
callback invoked when the Flutter application responds to the message, possibly null.
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setMessageHandler
@UiThread void setMessageHandler(@NonNull String channel, @Nullable BinaryMessenger.BinaryMessageHandler handler) Registers a handler to be invoked when the Flutter application sends a message to its host platform.Registration overwrites any previous registration for the same channel name. Use a null handler to deregister.
If no handler has been registered for a particular channel, any incoming message on that channel will be handled silently by sending a null reply.
- Parameters:
channel
- the nameString
of the channel.handler
- aBinaryMessenger.BinaryMessageHandler
to be invoked on incoming messages, or null.
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setMessageHandler
@UiThread default void setMessageHandler(@NonNull String channel, @Nullable BinaryMessenger.BinaryMessageHandler handler, @Nullable BinaryMessenger.TaskQueue taskQueue) Registers a handler to be invoked when the Flutter application sends a message to its host platform.Registration overwrites any previous registration for the same channel name. Use a null handler to deregister.
If no handler has been registered for a particular channel, any incoming message on that channel will be handled silently by sending a null reply.
- Parameters:
channel
- the nameString
of the channel.handler
- aBinaryMessenger.BinaryMessageHandler
to be invoked on incoming messages, or null.taskQueue
- aBinaryMessenger.TaskQueue
that specifies what thread will execute the handler. Specifying null means execute on the platform thread.
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enableBufferingIncomingMessages
default void enableBufferingIncomingMessages()Enables the ability to queue messages received from Dart.This is useful when there are pending channel handler registrations. For example, Dart may be initialized concurrently, and prior to the registration of the channel handlers. This implies that Dart may start sending messages while plugins are being registered.
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disableBufferingIncomingMessages
default void disableBufferingIncomingMessages()Disables the ability to queue messages received from Dart.This can be used after all pending channel handlers have been registered.
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