java - 开关机一次后按钮停止工作

Question

应用程序有一个图像按钮，可以打开和关闭屏幕亮度，但在打开和关闭一次后，该按钮不再起作用。有谁知道代码有什么问题吗？

import android.provider.Settings;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageButton;

public class ScreenFlashlight extends AppCompatActivity {
    private static String tag;
    private static final String TAG = tag ;
    private boolean brightnessOnOff;
    private ImageButton screenFlashOnOffButton;

    public ScreenFlashlight() throws Settings.SettingNotFoundException {
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_screen_flashlight);
        screenFlashOnOffButton = (ImageButton) findViewById(R.id.flashOnOffButton);
        brightnessOnOff = false;


    }
    public void screenFlashButtonClicked(View view) {

            try {
                if (brightnessOnOff) {

                    turnBrightnessOff();
                    Log.d(TAG, "screenFlashButtonClicked: ");
                } else {
                    brightnessOnOff = true;
                    turnBrightnessOn();
                    Log.d(TAG, "screenFlashButtonClicked: ");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

    }



    private void turnBrightnessOn() {
        try {
            screenFlashOnOffButton.setImageResource(R.drawable.screenonbutton);
            int currentBrightness = Settings.System.getInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS);
            //Screen refresh to add brightness

            WindowManager.LayoutParams lp = getWindow().getAttributes();
            lp.screenBrightness = currentBrightness/ 100.0f;
            getWindow().setAttributes(lp);


        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void turnBrightnessOff() {
        try {
            screenFlashOnOffButton.setImageResource(R.drawable.screenoffbutton);
            int currentBrightness = Settings.System.getInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS);
            //Refresh screen

            WindowManager.LayoutParams lpp = getWindow().getAttributes();
            lpp.screenBrightness = currentBrightness;
            getWindow().setAttributes(lpp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

Answer 1

当亮度关闭时，您永远不会将 brightnessOnOff 设置为 false，因此在您第一次按下按钮后它将具有值 true。所以你的代码每次都会进入if block 。您需要做的是在关闭亮度时将 brightnessOnOff 设置为 false，并在再次打开亮度时将其设置为 true。基本上，您需要在 true 和 false 之间交替 brightnessOnOff 才能正常工作