制作flashlightlight应用程序时Toogle ImageButton背景更快 - ＆＃34; android studio＆＃34;

Question

我是android studio的新手，目前我正在尝试使用IDE构建手电筒应用。一切都运转良好，我可以通过按ImageButton将开启和关闭设备的手电筒。我还使用 .setImageResource 来更改ImageButton的背景以显示ON和OFF状态。但是，我面临的问题是ON和OFF图像之间的变化并不快（不是即时!!! ），按下按钮时实际更改背景需要一些时间。所以，如果你们能帮助我如何在ImageButton中更快地切换两个图像，我真的很感激。

这是我的代码：

package com.example.android.flashlight;

import android.support.v7.app.AppCompatActivity;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.LinearInterpolator;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

ImageButton button;
private Camera camera;
private boolean isFlashOn;
private boolean hasFlash;
Parameters params;
MediaPlayer mp;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // flash switch button
    button = (ImageButton) findViewById(R.id.button);


    // First check if device is supporting flashlight or not
    hasFlash = getApplicationContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);


    if (!hasFlash) {
        // device doesn't support flash
        // Show alert message and close the application
        AlertDialog alert = new AlertDialog.Builder(MainActivity.this)
                .create();
        alert.setTitle("Error");
        alert.setMessage("Sorry, your device doesn't support flash light!");
        alert.setButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                // closing the application
                finish();
            }
         });
        alert.show();
        return;
    }

    // get the camera
    getCamera();

    // displaying button image
    toggleButtonImage();


    // Switch button click event to toggle flash on/off
    button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            if (isFlashOn) {
                // turn off flash
                turnOffFlash();


            } else {
                // turn on flash
                turnOnFlash();
            }
        }
    });
}
// Get the camera
private void getCamera() {
    if (camera == null) {
        try {
            camera = Camera.open();
            params = camera.getParameters();
        } catch (RuntimeException e) {
            Log.e("Camera Error", e.getMessage());
        }
    }
}
// Turning On flash
private void turnOnFlash() {
    if (!isFlashOn) {
        if (camera == null || params == null) {
            return;
        }
        params = camera.getParameters();
        params.setFlashMode(Parameters.FLASH_MODE_TORCH);
        camera.setParameters(params);
        camera.startPreview();
        isFlashOn = true;

        // changing button/switch image
        toggleButtonImage();
    }

}

// Turning Off flash
private void turnOffFlash() {
    if (isFlashOn) {
        if (camera == null || params == null) {
            return;
        }

        params = camera.getParameters();
        params.setFlashMode(Parameters.FLASH_MODE_OFF);
        camera.setParameters(params);
        camera.stopPreview();
        isFlashOn = false;

        //changing between images
        toggleButtonImage();

    }
}

/*
 * Toggle switch button images
 * changing image states to on / off
 * */
private void toggleButtonImage(){
    if(isFlashOn){
        button.setImageResource(R.drawable.button_on);
    }else{
        button.setImageResource(R.drawable.button_off);
    }
}

@Override
protected void onDestroy() {
    super.onDestroy();
}

@Override
protected void onPause() {
    super.onPause();

    // on pause turn off the flash
    turnOffFlash();
}

@Override
protected void onRestart() {
    super.onRestart();
}

@Override
protected void onResume() {
    super.onResume();

    // on resume turn on the flash
    if(hasFlash)
        turnOnFlash();
}

@Override
protected void onStart() {
    super.onStart();

    // on starting the app get the camera params
    getCamera();
}

@Override
protected void onStop() {
    super.onStop();

    // on stop release the camera
    if (camera != null) {
        camera.release();
        camera = null;
    }
}


}

toogleButtonImage（）是我更改ImageButton背景的方法。