Asynchronously opens file for reading.
For more details, see gio.file.File.read which is the synchronous version of this call.
When the operation is finished, callback will be called. You can then call gio.file.File.readFinish to get the result of the operation.
the [I/O priority][io-priority] of the request
optional #GCancellable object, null to ignore
a #GAsyncReadyCallback to call when the request is satisfied
Asynchronously opens file for reading.
For more details, see gio.file.File.read which is the synchronous version of this call.
When the operation is finished, callback will be called. You can then call gio.file.File.readFinish to get the result of the operation.