Question

CRED之类的某些应用在启动应用时显示Android默认锁定屏幕。输入锁定屏幕的图钉/指纹后，我们可以继续使用该应用程序。

那么如何弹出这样的屏幕，用户可以在其中输入锁定屏幕的图案/密码/指纹？

我猜想Android上有一些内置的类/框架，但是我找不到。

Answer 1

Call createConfirmDeviceCredentialIntent() on the KeyguardManager system service。这将返回一个Intent，您可以将其与startActivityForResult()一起使用。如果您在RESULT_OK中获得了onActivityResult()，则表明该用户已通过身份验证，可以安全进行。

例如，此活动具有一个触发上述流程的操作栏项：

/***
 Copyright (c) 2018 CommonsWare, LLC
 Licensed under the Apache License, Version 2.0 (the "License"); you may not
 use this file except in compliance with the License. You may obtain    a copy
 of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required
 by applicable law or agreed to in writing, software distributed under the
 License is distributed on an "AS IS" BASIS,    WITHOUT WARRANTIES OR CONDITIONS
 OF ANY KIND, either express or implied. See the License for the specific
 language governing permissions and limitations under the License.

 Covered in detail in the book _The Busy Coder's Guide to Android Development_
 https://commonsware.com/Android
 */

package com.commonsware.android.auth.check;

import android.annotation.TargetApi;
import android.app.Activity;
import android.app.KeyguardManager;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {
  private static final int REQUEST_CODE=1337;
  private KeyguardManager mgr;

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

    mgr=(KeyguardManager)getSystemService(KEYGUARD_SERVICE);

    ImageView device=findViewById(R.id.device);
    ImageView keyguard=findViewById(R.id.keyguard);

    if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.M) {
      if (mgr.isDeviceSecure()) {
        device.setImageResource(R.drawable.ic_lock_black_24dp);
      }
      else {
        device.setImageResource(R.drawable.ic_lock_open_black_24dp);
      }
    }
    else {
      device.setImageResource(R.drawable.ic_help_black_24dp);
    }

    if (mgr.isKeyguardSecure()) {
      keyguard.setImageResource(R.drawable.ic_lock_black_24dp);
    }
    else {
      keyguard.setImageResource(R.drawable.ic_lock_open_black_24dp);
    }
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.LOLLIPOP) {
      getMenuInflater().inflate(R.menu.actions, menu);
    }

    return super.onCreateOptionsMenu(menu);
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId()==R.id.auth) {
      authenticate();

      return true;
    }

    return super.onOptionsItemSelected(item);
  }

  @Override
  protected void onActivityResult(int requestCode, int resultCode,
                                  Intent data) {
    if (requestCode==REQUEST_CODE) {
      if (resultCode==RESULT_OK) {
        Toast.makeText(this, "Authenticated!", Toast.LENGTH_SHORT).show();
      }
      else {
        Toast.makeText(this, "WE ARE UNDER ATTACK!", Toast.LENGTH_SHORT).show();
      }
    }
  }

  @TargetApi(Build.VERSION_CODES.LOLLIPOP)
  private void authenticate() {
    Intent i=mgr.createConfirmDeviceCredentialIntent("title", "description");

    if (i==null) {
      Toast.makeText(this, "No authentication required!", Toast.LENGTH_SHORT).show();
    }
    else {
      startActivityForResult(i, REQUEST_CODE);
    }
  }
}

（摘自this sample app中的this book个人资料）

在启动应用程序时弹出Android默认锁定屏幕

1 个答案: