二维码扫描仪Android，onActivityResult方法未调用且Toast不显示

Question

我正在开发一个涉及QR扫描的应用程序。 我能够执行从我的应用程序调用的扫描仪应用程序库。扫描后，我需要存储捕获的值，但是不会调用在我的应用程序内部编写的onActivityResult方法。对此，我需要提供帮助：

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
    // Intent intent = new
    // Intent("com.google.zxing.client.android.SCAN");
    intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
    startActivityForResult(intent, 0);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    if (requestCode == 0) {
        if (resultCode == 1) {
            // Handle successful scan
            String capturedQrValue = intent.getStringExtra("RESULT");
            // String format =
            intent.getStringExtra("SCAN_RESULT_FORMAT");

            Toast.makeText(MainActivity.this,"Scan Result:" + capturedQrValue, Toast.LENGTH_SHORT).show();
            finish();
            Intent it = new Intent(MainActivity.this, ThirdActivity.class);
            it.putExtra("Code", capturedQrValue);
            startActivity(it);

        } else if (resultCode == RESULT_CANCELED) {
            // Handle cancel
        }

Answer 1

像这样更改您的onActivityResult，这可能会有所帮助

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) 
    {
    super.onActivityResult(requestCode, resultCode, data);

   if (requestCode == 0) {
        if (resultCode == 1) {
            // Handle successful scan
            String capturedQrValue = intent.getStringExtra("RESULT");
            // String format =
            intent.getStringExtra("SCAN_RESULT_FORMAT");

            Toast.makeText(MainActivity.this,"Scan Result:" + capturedQrValue, Toast.LENGTH_SHORT).show();
            finish();
            Intent it = new Intent(MainActivity.this, ThirdActivity.class);
            it.putExtra("Code", capturedQrValue);
            startActivity(it);

        } else if (resultCode == RESULT_CANCELED) {
            // Handle cancel
        }
}

Answer 2

RESULT_OK是int类型。

它的值等于-1

android.app.Activity.RESULT_OK = -1 [0xffffffff]参考网址http://developer.android.com/reference/android/app/Activity.html#RESULT_OK

public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == 0) {
    if (resultCode == RESULT_OK) {
        // Handle successful scan
        String capturedQrValue = intent.getStringExtra("RESULT");
        // String format =
        intent.getStringExtra("SCAN_RESULT_FORMAT");

        Toast.makeText(MainActivity.this,"Scan Result:" + capturedQrValue, Toast.LENGTH_SHORT).show();
        finish();
        Intent it = new Intent(MainActivity.this, ThirdActivity.class);
        it.putExtra("Code", capturedQrValue);
        startActivity(it);

    } else if (resultCode == RESULT_CANCELED) {
        // Handle cancel
    }

Answer 3

仅在您将zxing库用作第三方时，才将以下代码用于Intenting表单主要活动以捕获活动

Intent intent = new Intent("com.google.zxing.client.android.SCAN");
            intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
            startActivityForResult(intent, 0);

像这样更新您的onActivityResult方法。

//method for getting qr code from qr code image
        public void onActivityResult(int requestCode, int resultCode, Intent intent) {
            if (requestCode == 0) {
                if (resultCode == RESULT_OK) {
                    String contents = intent.getStringExtra("SCAN_RESULT");
                     Toast.makeText(MainActivity.this,"Scan Result:" + contents , Toast.LENGTH_SHORT).show();
      Intent it = new Intent(MainActivity.this, ThirdActivity.class);
                it.putExtra("Code", contents );
                startActivity(it);      

                    // Handle successful scan
                } else if (resultCode == RESULT_CANCELED) {
                    // Handle cancel
                    Log.d("the result is","not okjn");
                }
            }
        }

Answer 4

这是ZXing QR Code扫描程序库，使用它我们可以扫描任何QR Code。

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

import com.dm.zbar.android.scanner.ZBarConstants;
import com.dm.zbar.android.scanner.ZBarScannerActivity;

public class MainActivity extends Activity {
    private static final int ZBAR_SCANNER_REQUEST = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button button = (Button) findViewById(R.id.button1);
        button.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                if (isCameraAvailable()) {
                    try {
                        Intent intent = new Intent(MainActivity.this, ZBarScannerActivity.class);
                        startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
                    } catch (ActivityNotFoundException e) {
                        Toast.makeText(MainActivity.this, "Activity  " + e.getLocalizedMessage().toString(),
                                Toast.LENGTH_SHORT).show();
                    } catch (Exception e) {
                        Toast.makeText(MainActivity.this, e.getLocalizedMessage().toString(), Toast.LENGTH_SHORT)
                                .show();
                    }
                } else {
                    Toast.makeText(MainActivity.this, "Rear Facing Camera Unavailable", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
        case ZBAR_SCANNER_REQUEST:
            if (resultCode == RESULT_OK) {
                if (data.getStringExtra(ZBarConstants.SCAN_RESULT).length() > 0) {
                    Toast.makeText(this, "" + data.getStringExtra(ZBarConstants.SCAN_RESULT), Toast.LENGTH_SHORT)
                            .show();
                } else {
                    Toast.makeText(this, "No Event ID Found", Toast.LENGTH_SHORT).show();
                }

            } else if (resultCode == RESULT_CANCELED && data != null) {
                String error = data.getStringExtra(ZBarConstants.ERROR_INFO);
                if (!TextUtils.isEmpty(error)) {
                    Toast.makeText(this, error, Toast.LENGTH_SHORT).show();
                }
            }
            break;
        }
    }

    public boolean isCameraAvailable() {
        PackageManager pm = getPackageManager();
        return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);
    }

请在manifest.xml中提及这些权限

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

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.qrscandemo.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.dm.zbar.android.scanner.ZBarScannerActivity"
            android:screenOrientation="portrait" />
    </application>

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