java - Android 在复选框上振动

Question

我想构建一个简单的应用程序，该应用程序在单击复选框时振动并在再次单击后停止:

目前看起来像这样:

import android.content.Context;
import android.os.Vibrator;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;

public class MainActivity extends AppCompatActivity {

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

        Vibrator vibrator = (Vibrator) MainActivity.this.getSystemService(Context.VIBRATOR_SERVICE);
        final CheckBox vibrateCheckBox = (CheckBox) findViewById(R.id.checkPowerStrong);

        if(vibrateCheckBox.isChecked()) {
            while(vibrateCheckBox.isChecked()) {
                vibrator.vibrate(1000);
            }
        } else {
            vibrator.cancel();
        }

    }
}

但我确实收到错误:

Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate()

我授予 list 振动权限:

如何解决这个问题

Answer 1

它完全符合您的要求。做这样的事情

final Vibrator vibrator = (Vibrator) MainActivity.this.getSystemService(Context.VIBRATOR_SERVICE);
final CheckBox vibrateCheckBox = (CheckBox) findViewById(R.id.checkPowerStrong);

final Handler handler = new Handler();

final Runnable r = new Runnable() {
    public void run() {
        vibrator.vibrate(1000);
        handler.postDelayed(this, 1000);
    }
};

vibrateCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

       @Override
       public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
           if(vibrateCheckBox.isChecked()) {
               handler.postDelayed(r, 100);
           } else {
               handler.removeCallbacks(r);
               vibrator.cancel();
           }

       }
   }
);