android 指纹解锁

先看以下效果图（图中有几次的失败，不是因为它的识别率不高，是因为我用没录过的指纹测试）：

实现的方法很简单，不用引入依赖，它自带实现指纹的类，这里我就直接贴出代码(MainActivity.java)：

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private ImageView btnImg;
    private TextView txt;
    private FingerprintManager fingerprintManager = null;

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

    private void initView(){
        btnImg = (ImageView)findViewById(R.id.btnImg);
        btnImg.setOnClickListener(this);
        txt = (TextView)findViewById(R.id.txt);
    }

    @Override
    public void onClick(View view) {
        //隐藏点击的图片控件
        btnImg.setVisibility(View.GONE);
        //隐藏显示的文字
        txt.setVisibility(View.GONE);
        //获取系统服务对象
        fingerprintManager = (FingerprintManager)getSystemService(Context.FINGERPRINT_SERVICE);
        //检测是否有指纹识别的硬件
        if(!fingerprintManager.isHardwareDetected()){
            Toast.makeText(this, "您的手机没有指纹功能", Toast.LENGTH_SHORT).show();
            return;
        }

        //检查设备是否处于安全状态中
        KeyguardManager keyguardManager = (KeyguardManager)getSystemService(Context.KEYGUARD_SERVICE);
        if(!keyguardManager.isKeyguardSecure()){
            //如果不是出于安全状态中，跳转打开安全保护（锁屏等）
            return;
        }

        //检测系统中是否注册的指纹
        if(!fingerprintManager.hasEnrolledFingerprints()){
            //没有录入指纹，跳转到指纹录入
            Toast.makeText(this, "没有录入指纹", Toast.LENGTH_SHORT).show();
            return;
        }

        //开始指纹识别
        fingerprintManager.authenticate(null,cancellationSignal,0,myAuthCallback,null);
    }

    //初始化cancellationSignal类
    private CancellationSignal cancellationSignal = new CancellationSignal();

    //初始化MyAuthCallback
    private FingerprintManager.AuthenticationCallback myAuthCallback = new FingerprintManager.AuthenticationCallback() {
        @Override
        public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
            super.onAuthenticationSucceeded(result);
            Toast.makeText(MainActivity.this, "识别成功", Toast.LENGTH_SHORT).show();
            txt.setVisibility(View.VISIBLE);
            txt.setText("识别成功");
            txt.setTextColor(Color.parseColor("#01CCFF"));
            btnImg.setVisibility(View.VISIBLE);
        }

        @Override
        public void onAuthenticationFailed() {
            super.onAuthenticationFailed();
            Toast.makeText(MainActivity.this, "识别失败，请重试", Toast.LENGTH_SHORT).show();
            txt.setText("识别失败");
            txt.setTextColor(Color.parseColor("#D81B60"));
            txt.setVisibility(View.VISIBLE);
        }
    };
}

然后就是布局文件的代码：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:textSize="16sp"
        android:textStyle="bold"
        android:gravity="center"
        android:text="指纹认证"
        android:textColor="#FFF"
        android:background="#01CCFF"
        android:layout_width="match_parent"
        android:layout_height="45dp" />

    <TextView
        android:visibility="gone"
        android:id="@+id/txt"
        android:text="识别成功"
        android:gravity="center"
        android:textSize="20sp"
        android:textColor="#01CCFF"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <ImageView
        android:id="@+id/btnImg"
        android:src="@drawable/zhiwen"
        android:layout_marginBottom="100dp"
        android:layout_alignParentBottom="true"
        android:layout_centerInParent="true"
        android:scaleType="fitXY"
        android:layout_width="60dp"
        android:layout_height="60dp" />
</RelativeLayout>