具有Dexter的Android中的Easy Runtime权限

在棉花糖中引入的Android中的运行时权限(由于这些运行时权限)，用户可以在运行时向应用授予权限，同时还可以编写运行时权限的代码。有时，处理请求权限的任务变得如此困难，开发人员不得不编写大量代码。因此，我们将看到使用Dexter在Android中实现运行时权限。

Android中的Dexter是什么?

Dexter是一个库，可以帮助我们简化此任务，以便在Android中处理运行时权限。现在，我们将在我们的Android应用程序中看到此实现。

我们将在本文中构建什么?

我们将构建一个简单的应用程序，向用户显示一个按钮。单击该按钮后，我们将向用户显示运行时权限。因此，如果用户拒绝该权限，那么我们将显示打开设置屏幕并授予权限的选项。下面是一个简短的视频，我们将在其中看到我们将要构建的内容。注意，我们将使用Java语言实现该项目。

分步实施

步骤1：创建一个新项目

要在Android Studio中创建新项目，请参阅如何在Android Studio中创建/启动新项目。请注意，选择Java作为编程语言。

步骤2：在build.gradle文件中添加Dexter运行时权限的依赖性

导航到gradle脚本，然后构建到build.gradle(Module)级别。在依赖性部分的build.gradle文件中添加以下行。

implementation ‘com.karumi:dexter:6.2.2’

添加此依赖项后，现在同步您的项目。让我们转向XML部分。

步骤3：使用activity_main.xml文件

转到activity_main.xml文件，并参考以下代码。以下是activity_main.xml文件的代码。

步骤4：使用MainActivity。 Java文件

转到MainActivity。 Java文件并参考以下代码。下面是MainActivity的代码。 Java文件。在代码内部添加了注释，以更详细地了解代码。

Java

import android.Manifest;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.provider.Settings;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
  
import androidx.appcompat.app.AppCompatActivity;
  
import com.karumi.dexter.Dexter;
import com.karumi.dexter.MultiplePermissionsReport;
import com.karumi.dexter.PermissionToken;
import com.karumi.dexter.listener.DexterError;
import com.karumi.dexter.listener.PermissionRequest;
import com.karumi.dexter.listener.PermissionRequestErrorListener;
import com.karumi.dexter.listener.multi.MultiplePermissionsListener;
  
import java.util.List;
  
public class MainActivity extends AppCompatActivity {
      
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         
        // initializing our button and adding on click listener to it.
        Button requestPermissionsBtn = findViewById(R.id.idBtnRequestPermission);
        requestPermissionsBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // inside on click listener calling
                // method to request permission
                requestPermissions();
            }
        });
    }
  
    private void requestPermissions() {
        // below line is use to request 
        // permission in the current activity.
        Dexter.withActivity(this)
                // below line is use to request the number of 
                // permissions which are required in our app.
                .withPermissions(Manifest.permission.CAMERA,
                        // below is the list of permissions
                        Manifest.permission.ACCESS_FINE_LOCATION,
                        Manifest.permission.READ_CONTACTS)
                // after adding permissions we are 
                // calling an with listener method.
                .withListener(new MultiplePermissionsListener() {
                    @Override
                    public void onPermissionsChecked(MultiplePermissionsReport multiplePermissionsReport) {
                        // this method is called when all permissions are granted
                        if (multiplePermissionsReport.areAllPermissionsGranted()) {
                            // do you work now
                            Toast.makeText(MainActivity.this, "All the permissions are granted..", Toast.LENGTH_SHORT).show();
                        }
                        // check for permanent denial of any permission
                        if (multiplePermissionsReport.isAnyPermissionPermanentlyDenied()) {
                            // permission is denied permanently,
                            // we will show user a dialog message.
                            showSettingsDialog();
                        }
                    }
  
                    @Override
                    public void onPermissionRationaleShouldBeShown(List list, PermissionToken permissionToken) {
                        // this method is called when user grants some 
                        // permission and denies some of them.
                        permissionToken.continuePermissionRequest();
                    }
                }).withErrorListener(new PermissionRequestErrorListener() {
            // this method is use to handle error 
            // in runtime permissions
            @Override
            public void onError(DexterError error) {
                // we are displaying a toast message for error message.
                Toast.makeText(getApplicationContext(), "Error occurred! ", Toast.LENGTH_SHORT).show();
            }
        })
                // below line is use to run the permissions
                // on same thread and to check the permissions
                .onSameThread().check();
    }
  
    // below is the shoe setting dialog 
    // method which is use to display a
    // dialogue message.
    private void showSettingsDialog() {
        // we are displaying an alert dialog for permissions
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
          
        // below line is the title 
        // for our alert dialog.
        builder.setTitle("Need Permissions");
          
        // below line is our message for our dialog
        builder.setMessage("This app needs permission to use this feature. You can grant them in app settings.");
        builder.setPositiveButton("GOTO SETTINGS", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // this method is called on click on positive 
                // button and on clicking shit button we
                // are redirecting our user from our app to the 
                // settings page of our app.
                dialog.cancel();
                // below is the intent from which we 
                // are redirecting our user.
                Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                Uri uri = Uri.fromParts("package", getPackageName(), null);
                intent.setData(uri);
                startActivityForResult(intent, 101);
            }
        });
        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // this method is called when 
                // user click on negative button.
                dialog.cancel();
            }
        });
        // below line is used
        // to display our dialog
        builder.show();
    }
}

步骤5：在清单文件中添加所需的权限

导航至应用程序> AndroidManifest.xml文件，然后向其添加以下权限。

在我们的AndroidManifest.xml文件中添加这些权限之后。现在运行我们的应用程序，然后查看代码输出。

输出：

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