Android - 活动之间的小吃

Question

当我在活动B中的回调完成时,如何在活动A(coordinatorLayout在这里)中显示snackbar ？Snackbar需要我的coordinatorLayout,但我无法从Activity B中提供它.

活动B:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();

    if(id == android.R.id.home) {
        this.finish();
        return true;
    } else if(id == R.id.action_add) {
        callAddObject();
        this.finish();
        return true;
    }

    return super.onOptionsItemSelected(item);
}

public void callAddObject() {
    [...]
    client.newCall(request).enqueue(new Callback() {
        @Override
        public void onFailure(Request request, IOException e) {
            Log.d(TAG, "onFailure: " + e.getMessage());
            // show snackbar in Activity A
        }

        @Override
        public void onResponse(Response response) throws IOException {
            Log.d(TAG, "onResponse: " + response.body().string());
            // show snackbar in Activity A
        }
    });
}

感谢帮助.

Answer 1

您应该从活动A中打开活动B.

startActivityForResult(activityBIntent, FORM_REQUEST_CODE);

然后在提交表单时,使用结果完成活动B.

@Override
public void onFailure(Request request, IOException e) {
    Log.d(TAG, "onFailure: " + e.getMessage());
    // You might not want to finish the activity here, instead, you can show an error here
}

@Override
public void onResponse(Response response) throws IOException {
    Log.d(TAG, "onResponse: " + response.body().string());
    setResult(FORM_SUBMITTED);
    finish();
}

并在活动A中对此作出反应

@Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
    switch (requestCode) {
        case FORM_REQUEST_CODE:
            if (resultCode == ActivityB.FORM_SUBMITTED) {
                Snackbar.make(mView, "Form submitted", Snackbar.LENGTH_SHORT).show();
            }
    }
}

另一种解决方案是在IntentService中调用服务器,并在调用完成后使用某种事件总线(即Otto)向活动A发送事件.