我目前正在尝试为我的应用程序添加复制到剪贴板功能。我的应用程序是一个条码扫描器，成功扫描条形码/二维码后会产生2个按钮。这两个按钮是“访问”和“确定”，我想添加一个名为“复制到剪贴板”的额外按钮，它获取条码扫描器产生的值，并将其复制到android设备上的剪贴板。我使用的android-studio版本是2.3.3

这是我的源代码（按钮编程的部分在最后一个子程序中）：

package com.example.priyanka.qrbarcodescanner;

import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.net.Uri;
import android.os.Build;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import android.content.ClipboardManager;


import com.google.zxing.Result;

import me.dm7.barcodescanner.zxing.ZXingScannerView;

import static android.Manifest.permission.CAMERA;

public class MainActivity extends AppCompatActivity implements ZXingScannerView.ResultHandler {

    private static String myResult;
    private static final int REQUEST_CAMERA = 1;
    private ZXingScannerView scannerView;
    private static int camId = Camera.CameraInfo.CAMERA_FACING_BACK;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        scannerView = new ZXingScannerView(this);
        setContentView(scannerView);
        int currentApiVersion = Build.VERSION.SDK_INT;

        if(currentApiVersion >=  Build.VERSION_CODES.M)
        {
            if(checkPermission())
            {
                Toast.makeText(getApplicationContext(), "Permission already granted!", Toast.LENGTH_LONG).show();
            }
            else
            {
                requestPermission();
            }
        }
    }

    private boolean checkPermission()
    {
        return (ContextCompat.checkSelfPermission(getApplicationContext(), CAMERA) == PackageManager.PERMISSION_GRANTED);
    }

    private void requestPermission()
    {
        ActivityCompat.requestPermissions(this, new String[]{CAMERA}, REQUEST_CAMERA);
    }

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

        int currentapiVersion = android.os.Build.VERSION.SDK_INT;
        if (currentapiVersion >= android.os.Build.VERSION_CODES.M) {
            if (checkPermission()) {
                if(scannerView == null) {
                    scannerView = new ZXingScannerView(this);
                    setContentView(scannerView);
                }
                scannerView.setResultHandler(this);
                scannerView.startCamera();
            } else {
                requestPermission();
            }
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        scannerView.stopCamera();
    }

    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case REQUEST_CAMERA:
                if (grantResults.length > 0) {

                    boolean cameraAccepted = grantResults[0] == PackageManager.PERMISSION_GRANTED;
                    if (cameraAccepted){
                        Toast.makeText(getApplicationContext(), "Permission Granted, Now you can access camera", Toast.LENGTH_LONG).show();
                    }else {
                        Toast.makeText(getApplicationContext(), "Permission Denied, You cannot access and camera", Toast.LENGTH_LONG).show();
                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                            if (shouldShowRequestPermissionRationale(CAMERA)) {
                                showMessageOKCancel("You need to allow access to both the permissions",
                                        new DialogInterface.OnClickListener() {
                                            @Override
                                            public void onClick(DialogInterface dialog, int which) {
                                                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                                                    requestPermissions(new String[]{CAMERA},
                                                            REQUEST_CAMERA);
                                                }
                                            }
                                        });
                                return;
                            }
                        }
                    }
                }
                break;
        }
    }

    private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
        new android.support.v7.app.AlertDialog.Builder(MainActivity.this)
                .setMessage(message)
                .setPositiveButton("OK", okListener)
                .setNegativeButton("Cancel", null)
                .create()
                .show();
    }

    @Override
    public void handleResult(Result result) {
        Log.d("QRCodeScanner", result.getText());
        Log.d("QRCodeScanner", result.getBarcodeFormat().toString());
        myResult = result.getText();


        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Scan Result");
        builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                scannerView.resumeCameraPreview(MainActivity.this);

            }
        });
        builder.setNeutralButton("Visit", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Intent browserIntent;
                if (myResult.startsWith("http://") || myResult.startsWith("https://"))
                    browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(myResult));
                else
                    browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://google.com/search?q=" + myResult));
                startActivity(browserIntent);
            }
        });
        builder.setMessage(result.getText());
        AlertDialog alert1 = builder.create();
        alert1.show();
    }
}