在Android Studio中,可以使用ZXing库来读取在Java中定义的QR码。下面是一个使用ZXing库的示例代码:
implementation 'com.google.zxing:core:3.4.1'
implementation 'com.journeyapps:zxing-android-embedded:4.2.0'
QRCodeScannerActivity
的类,并在该类中添加以下代码:import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import androidx.annotation.Nullable;
import com.google.zxing.integration.android.IntentIntegrator;
import com.google.zxing.integration.android.IntentResult;
public class QRCodeScannerActivity extends Activity {
private Button scanButton;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_qr_code_scanner);
scanButton = findViewById(R.id.scan_button);
scanButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 创建IntentIntegrator对象,并启动扫描
IntentIntegrator integrator = new IntentIntegrator(QRCodeScannerActivity.this);
integrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE_TYPES);
integrator.setPrompt("Scan a QR Code");
integrator.setCameraId(0);
integrator.setBeepEnabled(false);
integrator.setBarcodeImageEnabled(false);
integrator.initiateScan();
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// 获取扫描结果
IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
if (result != null) {
if (result.getContents() == null) {
Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show();
} else {
String qrCodeData = result.getContents();
Toast.makeText(this, "Scanned: " + qrCodeData, Toast.LENGTH_LONG).show();
Log.d("QRCodeScannerActivity", "Scanned: " + qrCodeData);
}
}
}
}
activity_qr_code_scanner.xml
的布局文件,并添加以下代码:
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
private Button startScanButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startScanButton = findViewById(R.id.start_scan_button);
startScanButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, QRCodeScannerActivity.class);
startActivity(intent);
}
});
}
}
这样,当你点击startScanButton
按钮时,将启动扫描QR码的Activity。扫描成功后,将在日志中打印出QR码的内容,并显示一个Toast消息。