Question

嘿我正在android studio中设计一个应用程序。我需要相机的许可。我在AndroidManifest.xml文件中包含了<html lang=="en"> <meta name="viewport" content="width=device-width, initial-scale=1"> <head> <meta charset="utf-8"> <title>Deut65</title> <link href="site.css" rel="stylesheet"> </head> <body> <ul id="nav"> <img id="logo" src="logo.png"></img> <li><a href="#home">Home</a></li> <li><a href="#editor">Editor</a></li> <li><a href="#about">About</a></li> </ul> <div id="image-div"> <img id="top-image"src="fotoDeut65.jpeg"> <button id="image-button">Button</button> </div> <style> #image-div{ top: -50%; left: -50%; width: 100%; height: 100%; } #top-image{ position: absolute; top: 0; left: 0; right: 0; bottom: 0; margin: auto; min-width: 100%; min-height: 100%; width: 400px; height: auto; } #image-button{ position: relative; z-index: 1; margin-left: auto; margin-right: auto; top: 191px; left: 420px; right: -420px; bottom: -191px; } </style>  </body> </html>。它在除Marshmallow之外的所有Android版本中都能正常工作。如何默认获得相机权限？如果不可能，我该如何向用户询问？

Answer 1

首先检查用户是否已授予权限：

if (ContextCompat.checkSelfPermission(context, Manifest.permission.CAMERA)
    == PackageManager.PERMISSION_DENIED)

然后，您可以使用它来向用户请求：

ActivityCompat.requestPermissions(activity, new String[] {Manifest.permission.CAMERA}, requestCode);

在Marshmallow中，它会出现在对话框中

Answer 2

您可以尝试使用以下代码在marshmallow中请求相机权限。

首先检查用户是否授予权限。如果用户没有被授予   权限然后请求相机许可。

private static final int MY_CAMERA_REQUEST_CODE = 100;

    if (checkSelfPermission(Manifest.permission.CAMERA)
                        != PackageManager.PERMISSION_GRANTED) {
               requestPermissions(new String[]{Manifest.permission.CAMERA},
                            MY_CAMERA_REQUEST_CODE);
                }

请求权限后，将显示警告以询问权限包含允许和拒绝选项。点击动作后我们可以得到使用以下方法的请求结果。

@Override

    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

    if (requestCode == MY_CAMERA_REQUEST_CODE) {

            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();

            } else {

                Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();

            }

        }}//end onRequestPermissionsResult

Answer 3

RxPermission是将代码排成1行的最佳库。

要获得摄像头许可，解决方法是这样的。

1）首先在您的manifest.xml中添加此权限。

<uses-permission android:name="android.permission.CAMERA" />

2）然后询问运行时权限。

 new RxPermissions(this)
.request(Manifest.permission.CAMERA) // ask single or multiple permission once
.subscribe(granted -> {
    if (granted) {
       // All requested permissions are granted
    } else {
       // At least one permission is denied
    }
});

将此库添加到您的build.gradle

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

dependencies {
    implementation 'com.github.tbruyelle:rxpermissions:0.10.1'
    implementation 'com.jakewharton.rxbinding2:rxbinding:2.1.1'
}

这不容易吗？

Answer 4

check using this
if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.CAMERA)
            == PackageManager.PERMISSION_DENIED)

和

Answer 5

这对我有用，来源是here

int MY_PERMISSIONS_REQUEST_CAMERA=0;
        // Here, this is the current activity
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)
        {
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA))
            {

            }
            else
            {
                ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.CAMERA}, MY_PERMISSIONS_REQUEST_CAMERA );
                // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
                // app-defined int constant. The callback method gets the
                // result of the request.
            }
        }

Answer 6

click here获取完整的源代码，并了解更多。

在获得许可之前，您可以检查api版本，

  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
  {
      if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {

      } 
      else
      {
         ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 401);
      }
  }
  else
  {
    // if version is below m then write code here,          
  }

获取权限对话框的结果，

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == 401) {
        if (grantResults.length == 0 || grantResults == null) {

        } else if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            openGallery();
        } else if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
        }
    } else if (requestCode == 402) {
        if (grantResults.length == 0 || grantResults == null) {

        } else if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {

        } else if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
        }
    }
}

Answer 7

我尝试添加以下代码：

private static final int MY_CAMERA_REQUEST_CODE = 100;

@RequiresApi(api = Build.VERSION_CODES.M)

if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
        requestPermissions(new String[]{Manifest.permission.CAMERA}, MY_CAMERA_REQUEST_CODE);
    }

关于 onCreate 函数和以下代码：

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == MY_CAMERA_REQUEST_CODE) {
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
        } else {
            Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
        }
    }
}

这对我有用:)

Answer 8

请求权限在以下代码中，我们将请求相机许可：

在Java中

EasyPermissions是一个包装器库，用于简化针对Android M或更高版本的基本系统权限逻辑。

安装通过将以下依赖项添加到build.gradle文件中来安装EasyPermissions：

依赖性{

// For developers using AndroidX in their applications
implementation 'pub.devrel:easypermissions:3.0.0'

// For developers using the Android Support Library
implementation 'pub.devrel:easypermissions:2.0.1'

}

private void askAboutCamera（）{

    EasyPermissions.requestPermissions(
            this,
            "A partir deste ponto a permissão de câmera é necessária.",
            CAMERA_REQUEST_CODE,
            Manifest.permission.CAMERA );

}

如何在Android中获得相机的许可。（特别是Marshmallow）

8 个答案: