<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  xmlns:tools="http://schemas.android.com/tools" 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:gravity="center" 
  android:orientation="vertical" 
  android:paddingBottom="@dimen/activity_vertical_margin" 
  android:paddingLeft="@dimen/activity_horizontal_margin" 
  android:paddingRight="@dimen/activity_horizontal_margin" 
  android:paddingTop="@dimen/activity_vertical_margin" 
  tools:context="com.liu.finger.MainActivity"> 
 
  <TextView 
    android:id="@+id/textView" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Hello World!" 
    android:textSize="18sp" /> 
 
  <Button 
    android:id="@+id/btn_activity_main_finger" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignParentStart="true" 
    android:layout_below="@+id/textView" 
    android:layout_marginTop="54dp" 
    android:text="指紋識別" /> 
</LinearLayout> 

package com.liu.finger; 
 
import android.Manifest; 
import android.app.KeyguardManager; 
import android.content.Context; 
import android.content.Intent; 
import android.content.pm.PackageManager; 
import android.hardware.fingerprint.FingerprintManager; 
import android.os.Bundle; 
import android.os.CancellationSignal; 
import android.support.v4.app.ActivityCompat; 
import android.support.v4.app.FragmentActivity; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.Toast; 
 
 
 
public class MainActivity extends FragmentActivity { 
  FingerprintManager manager; 
  KeyguardManager mKeyManager; 
  private final static int REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS = 0; 
  private final static String TAG = "finger_log"; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    manager = (FingerprintManager) this.getSystemService(Context.FINGERPRINT_SERVICE); 
    mKeyManager = (KeyguardManager) this.getSystemService(Context.KEYGUARD_SERVICE); 
    Button btn_finger = (Button) findViewById(R.id.btn_activity_main_finger); 
    btn_finger.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
        if (isFinger()) { 
          Toast.makeText(MainActivity.this, "請進行指紋識別", Toast.LENGTH_LONG).show(); 
          Log(TAG, "keyi"); 
          startListening(null); 
        } 
      } 
    }); 
 
  } 
 
  public boolean isFinger() { 
 
    //android studio 上，沒有這個會報錯 
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) { 
      Toast.makeText(this, "沒有指紋識別權限", Toast.LENGTH_SHORT).show(); 
      return false; 
    } 
    Log(TAG, "有指紋權限"); 
    //判斷硬件是否支持指紋識別 
    if (!manager.isHardwareDetected()) { 
      Toast.makeText(this, "沒有指紋識別模塊", Toast.LENGTH_SHORT).show(); 
      return false; 
    } 
   Log(TAG, "有指紋模塊"); 
    //判斷 是否開啟鎖屏密碼 
 
    if (!mKeyManager.isKeyguardSecure()) { 
      Toast.makeText(this, "沒有開啟鎖屏密碼", Toast.LENGTH_SHORT).show(); 
      return false; 
    } 
    Log(TAG, "已開啟鎖屏密碼"); 
    //判斷是否有指紋錄入 
    if (!manager.hasEnrolledFingerprints()) { 
      Toast.makeText(this, "沒有錄入指紋", Toast.LENGTH_SHORT).show(); 
      return false; 
    } 
    Log(TAG, "已錄入指紋"); 
 
    return true; 
  } 
 
  CancellationSignal mCancellationSignal = new CancellationSignal(); 
  //回調方法 
  FingerprintManager.AuthenticationCallback mSelfCancelled = new FingerprintManager.AuthenticationCallback() { 
    @Override 
    public void onAuthenticationError(int errorCode, CharSequence errString) { 
      //但多次指紋密碼驗證錯誤后，進入此方法；并且，不能短時間內調用指紋驗證 
      Toast.makeText(MainActivity.this, errString, Toast.LENGTH_SHORT).show(); 
      showAuthenticationScreen(); 
    } 
 
    @Override 
    public void onAuthenticationHelp(int helpCode, CharSequence helpString) { 
 
      Toast.makeText(MainActivity.this, helpString, Toast.LENGTH_SHORT).show(); 
    } 
 
    @Override 
    public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) { 
 
      Toast.makeText(MainActivity.this, "指紋識別成功", Toast.LENGTH_SHORT).show(); 
    } 
 
    @Override 
    public void onAuthenticationFailed() { 
      Toast.makeText(MainActivity.this, "指紋識別失敗", Toast.LENGTH_SHORT).show(); 
    } 
  }; 
 
 
  public void startListening(FingerprintManager.CryptoObject cryptoObject) { 
    //android studio 上，沒有這個會報錯 
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) { 
      Toast.makeText(this, "沒有指紋識別權限", Toast.LENGTH_SHORT).show(); 
      return; 
    } 
    manager.authenticate(cryptoObject, mCancellationSignal, 0, mSelfCancelled, null); 
 
 
  } 
 
  /** 
   * 鎖屏密碼 
   */ 
  private void showAuthenticationScreen() { 
 
    Intent intent = mKeyManager.createConfirmDeviceCredentialIntent("finger", "測試指紋識別"); 
    if (intent != null) { 
      startActivityForResult(intent, REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS); 
    } 
  } 
 
  @Override 
  protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    if (requestCode == REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS) { 
      // Challenge completed, proceed with using cipher 
      if (resultCode == RESULT_OK) { 
        Toast.makeText(this, "識別成功", Toast.LENGTH_SHORT).show(); 
      } else { 
        Toast.makeText(this, "識別失敗", Toast.LENGTH_SHORT).show(); 
      } 
    } 
  } 
 
  private void Log(String tag, String msg) { 
    Log.d(tag, msg); 
  } 
}