Android实现扫一扫识别数字功能

下面是针对“Android实现扫一扫识别数字功能”的完整攻略。

步骤一：添加ZXing库

1. 下载并导入ZXing库。

2. 在build.gradle文件中添加ZXing依赖

dependencies {
    implementation 'com.google.zxing:core:3.3.3'
}

步骤二：添加扫码识别逻辑

1. 在AndroidManifest.xml中添加相机权限

<uses-permission android:name="android.permission.CAMERA" />

1. 创建扫码Activity

public class ScanActivity extends AppCompatActivity implements ZXingScannerView.ResultHandler {
    private static final String TAG = ScanActivity.class.getSimpleName();
    private ZXingScannerView mScannerView;

    @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);
        mScannerView = new ZXingScannerView(this);
        setContentView(mScannerView);
    }

    @Override
    public void onResume() {
        super.onResume();
        mScannerView.setResultHandler(this);
        mScannerView.startCamera();
    }

    @Override
    public void onPause() {
        super.onPause();
        mScannerView.stopCamera();
    }

    @Override
    public void handleResult(Result result) {
        String code = result.getText();
        if (code != null && code.matches("[0-9]+")) { // 匹配纯数字
            // 扫码识别成功，将扫描结果返回给调用者
            Intent intent = new Intent();
            intent.putExtra("code", code);
            setResult(RESULT_OK, intent);
            finish();
        } else {
            // 提示扫码结果格式不正确
            Toast.makeText(this, "扫描结果不是纯数字", Toast.LENGTH_SHORT).show();
            mScannerView.resumeCameraPreview(this);
        }
    }
}

步骤三：调用扫码Activity获取数字结果

1. 在需要使用扫码功能的Activity中添加按钮

<Button
    android:id="@+id/btn_scan"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="扫一扫" />

1. 实现按钮的点击事件

public class MainActivity extends AppCompatActivity {
    private static final int REQUEST_CODE_SCAN = 1;

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

        Button btnScan = findViewById(R.id.btn_scan);
        btnScan.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, ScanActivity.class);
                startActivityForResult(intent, REQUEST_CODE_SCAN);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE_SCAN && resultCode == RESULT_OK && data != null) {
            String code = data.getStringExtra("code");
            if (code != null) {
                // 扫码识别成功
                Toast.makeText(this, "扫描结果：" + code, Toast.LENGTH_SHORT).show();
            } else {
                // 扫码失败
                Toast.makeText(this, "扫描失败", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

示例1：使用扫码功能获取验证密码

假设有一个应用需要进行短信验证码登录，使用扫码功能可以简化用户的操作。具体实现方式如下：

1. 在服务端生成随机的四位数字密码

import java.util.Random;

public class PasswordGenerator {
    private static final int PASSWORD_LENGTH = 4;

    public static String generate() {
        StringBuilder builder = new StringBuilder();
        Random random = new Random();
        for (int i = 0; i < PASSWORD_LENGTH; i++) {
            builder.append(random.nextInt(10));
        }
        return builder.toString();
    }
}

1. 在登录Activity中添加获取验证码按钮

<Button
    android:id="@+id/btn_get_password"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="获取验证码" />

1. 在点击事件中生成密码并显示在控件上

public class LoginActivity extends AppCompatActivity {
    private TextView mTextPassword;

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

        mTextPassword = findViewById(R.id.text_password);

        Button btnGetPassword = findViewById(R.id.btn_get_password);
        btnGetPassword.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String password = PasswordGenerator.generate();
                mTextPassword.setText(password);
            }
        });
    }

    // ...
}

1. 在登录Activity中添加扫码按钮

<Button
    android:id="@+id/btn_scan_code"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="扫描二维码登录" />

1. 实现扫码按钮的点击事件

public class LoginActivity extends AppCompatActivity {
    private static final int REQUEST_CODE_SCAN = 1;
    private TextView mTextPassword;

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

        mTextPassword = findViewById(R.id.text_password);

        Button btnGetPassword = findViewById(R.id.btn_get_password);
        btnGetPassword.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String password = PasswordGenerator.generate();
                mTextPassword.setText(password);
            }
        });

        Button btnScanCode = findViewById(R.id.btn_scan_code);
        btnScanCode.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(LoginActivity.this, ScanActivity.class);
                startActivityForResult(intent, REQUEST_CODE_SCAN);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE_SCAN && resultCode == RESULT_OK && data != null) {
            String code = data.getStringExtra("code");
            if (code != null && code.equals(mTextPassword.getText().toString())) {
                // 扫码成功，验证密码正确，登录成功
                Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show();
            } else {
                // 验证密码错误，登录失败
                Toast.makeText(this, "密码错误", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

示例2：使用扫码功能获取支付订单号

假设有一个支付功能，需要用户输入订单号才能进行支付，使用扫码功能可以让用户快速获得订单号。具体实现方式如下：

1. 在支付Activity中添加获取支付订单按钮

<Button
    android:id="@+id/btn_get_order"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="获取支付订单" />

1. 在点击事件中生成订单号并显示在控件上

public class PaymentActivity extends AppCompatActivity {
    private TextView mTextOrder;

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

        mTextOrder = findViewById(R.id.text_order);

        Button btnGetOrder = findViewById(R.id.btn_get_order);
        btnGetOrder.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String order = OrderGenerator.generate();
                mTextOrder.setText(order);
            }
        });
    }

    // ...
}

1. 在支付Activity中添加扫码按钮

<Button
    android:id="@+id/btn_scan_code"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="扫描二维码支付" />

1. 实现扫码按钮的点击事件

public class PaymentActivity extends AppCompatActivity {
    private static final int REQUEST_CODE_SCAN = 1;
    private TextView mTextOrder;

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

        mTextOrder = findViewById(R.id.text_order);

        Button btnGetOrder = findViewById(R.id.btn_get_order);
        btnGetOrder.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String order = OrderGenerator.generate();
                mTextOrder.setText(order);
            }
        });

        Button btnScanCode = findViewById(R.id.btn_scan_code);
        btnScanCode.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(PaymentActivity.this, ScanActivity.class);
                startActivityForResult(intent, REQUEST_CODE_SCAN);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE_SCAN && resultCode == RESULT_OK && data != null) {
            String code = data.getStringExtra("code");
            if (code != null && code.equals(mTextOrder.getText().toString())) {
                // 扫码成功，验证订单正确，进行支付
                Toast.makeText(this, "支付成功", Toast.LENGTH_SHORT).show();
            } else {
                // 验证订单错误，支付失败
                Toast.makeText(this, "订单错误", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

以上是实现“Android实现扫一扫识别数字功能”的完整攻略，希望能对你有所帮助！