java - 比多次 if (){do} 检查更优雅的代码

Question

结合三个标准，可以通过更优雅的解决方案来实现以下行为吗？如果读了很多，switch case 就会有难闻的气味，否则就会嵌套。

    @Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    Switch sr = (Switch) findViewById(R.id.switch_ros);
    Switch srs = (Switch) findViewById(R.id.switch_ros_stream);
    boolean wifi_state = isConnected(this);
     if (buttonView.getId() == R.id.switch_ros & buttonView.isChecked() & wifi_state) {
        Toast.makeText(this, "ros intent ready", Toast.LENGTH_SHORT).show();
    }
    if (buttonView.getId() == R.id.switch_ros & buttonView.isChecked() & !wifi_state) {
        Toast.makeText(this, "log: wifi bad", Toast.LENGTH_SHORT).show();
        sr.setChecked(false);
    }
    if (buttonView.getId() == R.id.switch_ros & !buttonView.isChecked()) {
        Toast.makeText(this, "ros intent stopped", Toast.LENGTH_SHORT).show();
        srs.setChecked(false); // and stop ros intent, automatically calls onCheckedChange again
    }
    if (buttonView.getId() == R.id.switch_ros_stream & buttonView.isChecked() & sr.isChecked()) {
        Toast.makeText(this, "stream intent ready", Toast.LENGTH_SHORT).show();
    }
    if (buttonView.getId() == R.id.switch_ros_stream & buttonView.isChecked() & !sr.isChecked()) {
        Toast.makeText(this, "log: first switch is off", Toast.LENGTH_SHORT).show();
        srs.setChecked(false);
    }
    if (buttonView.getId() == R.id.switch_ros_stream & !buttonView.isChecked()) {
        Toast.makeText(this, "stream intent stopped", Toast.LENGTH_SHORT).show();
        // and stop stream intent
    }
}

Answer 1

我会将它们推出到一个枚举中。这是为您完成的前两个。

enum Check {

    IntentReady {

                @Override
                boolean check(CompoundButton buttonView, boolean wifi_state) {
                    return buttonView.getId() == R.id.switch_ros & buttonView.isChecked() & wifi_state;
                }

                @Override
                void apply(Switch sr, Switch srs) {
                    Toast.makeText(this, "ros intent ready", Toast.LENGTH_SHORT).show();
                }

            },
    WIFIBad {

                @Override
                boolean check(CompoundButton buttonView, boolean wifi_state) {
                    return buttonView.getId() == R.id.switch_ros & buttonView.isChecked() & !wifi_state;
                }

                @Override
                void apply(Switch sr, Switch srs) {
                    Toast.makeText(this, "log: wifi bad", Toast.LENGTH_SHORT).show();
                    sr.setChecked(false);
                }

            };

    abstract boolean check(CompoundButton buttonView, boolean wifi_state);

    abstract void apply(Switch sr, Switch srs);
}

public void onCheckedChangedNew(CompoundButton buttonView, boolean isChecked) {
    Switch sr = (Switch) findViewById(R.id.switch_ros);
    Switch srs = (Switch) findViewById(R.id.switch_ros_stream);
    boolean wifi_state = isConnected(this);
    for ( Check c : Check.values()) {
        if ( c.check(buttonView, wifi_state)) {
            c.apply(sr, srs);
        }
    }
}

这里的主要好处是您可以自动转换代码。完成后，您将拥有更大的灵 active 和清晰度。