android

Question

我正在我的应用程序中实施指纹验证。我已在应用程序中成功验证指纹。但问题是，我想从指纹助手 class 调用 Main Activity 中的 Asynctask class。

下面是 FingerPrintHelper.java class 的代码:

public class FingerprintHandler extends FingerprintManager.AuthenticationCallback {


    private Context context;


    // Constructor
    public FingerprintHandler(Context mContext) {
        context = mContext;
    }


    public void startAuth(FingerprintManager manager, FingerprintManager.CryptoObject cryptoObject) {
        CancellationSignal cancellationSignal = new CancellationSignal();
        if (ActivityCompat.checkSelfPermission(context, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        manager.authenticate(cryptoObject, cancellationSignal, 0, this, null);
    }


    @Override
    public void onAuthenticationError(int errMsgId, CharSequence errString) {
        this.update("Fingerprint Authentication error\n" + errString, false);
    }


    @Override
    public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
        this.update("Fingerprint Authentication help\n" + helpString, false);
    }


    @Override
    public void onAuthenticationFailed() {
        this.update("Fingerprint Authentication failed.", false);
        Vibrator v = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);
        v.vibrate(1000);

        TextView lblFingerPrintError = (TextView) ((Activity)context).findViewById(R.id.lblFingerPrintError);
        lblFingerPrintError.setVisibility(View.VISIBLE);
        lblFingerPrintError.setText("Finger print did not match");
    }


    @Override
    public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
        this.update("Fingerprint Authentication succeeded.", true);


        context.startActivity(new Intent(context, HomePage.class));
    }


    public void update(String e, Boolean success){
        if(success){
            Log.i("WW", "Matched");
        }
    }
}

在方法 onAuthenticationSucceeded() 中，我想调用 Asynctask Class，它是 Main Activity。

如果有人对此有解决方案，请回复。

谢谢。

Answer 1

您可以将回调传递给您的调用 activity 以了解身份验证完成，如下所示。

回调接口

    public interface CallBackInterface  {
    void onAuthenticationSucceed();
}

当您从 activity 调用 FingerprintHandler 时，只需使用这样的方法或构造函数传递引用。

// Constructor
public FingerprintHandler(Context mContext,CallBackInterface callback) {
    context = mContext;
    this.callback = callback;
}

现在您可以使用此引用通知调用方 activity 身份验证完成，如下所示。

 @Override
    public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
        this.update("Fingerprint Authentication succeeded.", true);
        //notify the caller about success
        callback.onAuthenticationSucceed();
    }

FingerprintHandler 的最终代码如下。

public class FingerprintHandler extends FingerprintManager.AuthenticationCallback {


private Context context;
private CallBackInterface callback;

// Constructor
public FingerprintHandler(Context mContext, CallBackInterface callback) {
    context = mContext;
    this.callback = callback;
}


public void startAuth(FingerprintManager manager, FingerprintManager.CryptoObject cryptoObject) {
    CancellationSignal cancellationSignal = new CancellationSignal();
    if (ActivityCompat.checkSelfPermission(context, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {
        return;
    }
    manager.authenticate(cryptoObject, cancellationSignal, 0, this, null);
}


@Override
public void onAuthenticationError(int errMsgId, CharSequence errString) {
    this.update("Fingerprint Authentication error\n" + errString, false);
}


@Override
public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
    this.update("Fingerprint Authentication help\n" + helpString, false);
}


@Override
public void onAuthenticationFailed() {
    this.update("Fingerprint Authentication failed.", false);
    Vibrator v = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);
    v.vibrate(1000);

    TextView lblFingerPrintError = (TextView) ((Activity)context).findViewById(R.id.lblFingerPrintError);
    lblFingerPrintError.setVisibility(View.VISIBLE);
    lblFingerPrintError.setText("Finger print did not match");
}


@Override
public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
    this.update("Fingerprint Authentication succeeded.", true);
    //here notify the caller about the success
    callback.onAuthenticationSucceed();

   // context.startActivity(new Intent(context, HomePage.class));
}


public void update(String e, Boolean success){
    if(success){
        Log.i("WW", "Matched");
    }
}

}

并且在您使用构造函数传递引用的 activity 中，您必须覆盖 onAuthenticationSucceed() 所以现在在这里调用您的异步任务

@Override
public void onAuthenticationSucceed(){
  //here start your async task.
}

android - 如何从 FIngerPrintHelper class 在 Main Activity 中调用 class 扩展 Asynctask

android - How to call a class extending Asynctask in the Main Activity from FIngerPrintHelper class

java

android-fingerprint-api