Flutter update progress in compute method

user_14079992 0
Viewed 731

I have to save many images to the device to make videos.
As saving multiple images takes so much time and resources, I use compute to save images.

I want to show the progress in saving images so that users can notice how much time left for video.
But, calling progressDialog.update(progress: progress) in compute cause error like this

[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: Invalid argument(s): Illegal argument in isolate message : (object is a closure - Function _handleBuildScheduled@587399801:.)

How can I show progress in compute method?

single-threaded dart flutter
2 Answers

Thanks to pskink, I find out solution.
First, create RecceivePort and pass receivePort.sendPort to compute method.

ReceivePort receivePort;

myComputeFunction(args) {
    Int someParameter = args[0]
    String otherParameter = args[1]
    SendPort port = args[2]

    //if you want to send some message
    port.send("your message here(passing double was ok)")
}


callingComputeFunction() {
    await compute(myComputeFunction, [1, "string", receivePort.sendPort]);
}

And before you call compute, don't forget to receivePort.listen().

receivePort.listen((dynamic message) {
      //do whatever you want to do with message!
    });
user_140799920 
progressDialog.update(progress: 50.0)   add Double Value Here it will work

Your progress value is not double so you are getting this error

user_84800690
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