//绑定用户输入到ViewModel
RxTextView.textChanges(phoneNumberEditText).subscribe(viewModel.phoneNumber());
RxTextView.textChanges(verificationCodeEditText).subscribe(viewModel.verificationCode());

//绑定按钮和command，当command正在执行或者输入不合法时，按钮将处于disable状态
RxCommandBinder.bind(verificationCodeButton, viewModel.verificationCodeCommand());
RxCommandBinder.bind(loginButton, viewModel.loginCommand());

//处理获取验证码执行状态
viewModel.verificationCodeCommand()
        .executing()
        .subscribe(executing -> {
            if (executing) {
                verificationCodeButton.setText("fetch...");
            } else {
                verificationCodeButton.setText("fetch code");
            }
        });

//处理获取验证码成功的情形，已经过滤了发生错误的情形，不需要在这里处理失败的情况
viewModel.verificationCodeCommand()
        .switchToLatest()
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(result -> Toast.makeText(LoginActivity.this, result, Toast.LENGTH_LONG).show());

//处理获取验证码成功后，正在倒数的情形
viewModel.countdownCommand()
        .switchToLatest()
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(s -> verificationCodeButton.setText(s));

//处理倒计时结束后的情形
viewModel.countdownCommand()
        .executing()
        .subscribe(executing -> {
            if (!executing) {
                verificationCodeButton.setText("fetch code");
            }
        });

//处理登录执行状态
viewModel.loginCommand()
        .executing()
        .subscribe(executing -> {
            if (executing) {
                loginButton.setText("login...");
            } else {
                loginButton.setText("login");
            }
        });

//处理登录失败或者获取验证码失败的情形
Observable.merge(
        viewModel.verificationCodeCommand().errors(),
        viewModel.loginCommand().errors())
        .subscribe(throwable ->
                Toast.makeText(LoginActivity.this, throwable.getLocalizedMessage(), Toast.LENGTH_LONG).show()
        );

//处理登录成功后的情形
viewModel.loginCommand()
        .switchToLatest()
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(success -> {
            if (success) {
                Toast.makeText(LoginActivity.this, "login success!! Now goto the MainActivity.", Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(LoginActivity.this, "login fail!!", Toast.LENGTH_LONG).show();
            }
        });