Question

尝试制作绘画应用。除了保存按钮之外的所有功能都按预期运行。每当我点击保存按钮时，它都没有保存，我收到错误java.lang.SecurityException: Permission Denial: writing com.android.providers.media.MediaProvider uri content://media/external/images/media from pid=10397, uid=10298 requires android.permission.WRITE_EXTERNAL_STORAGE, or grantUriPermission()。

else if(view.getId()==R.id.save_btn){
                //save drawing
                AlertDialog.Builder saveDialog = new AlertDialog.Builder(this);
                saveDialog.setTitle("Save drawing");
                saveDialog.setMessage("Save drawing to device Gallery?");
                saveDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
                    public void onClick(DialogInterface dialog, int which){
                        //save drawing
                    }
                });
                saveDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
                    public void onClick(DialogInterface dialog, int which){
                        dialog.cancel();
                    }
                });
                saveDialog.show();
                drawView.setDrawingCacheEnabled(true);
                String imgSaved = MediaStore.Images.Media.insertImage(
                        getContentResolver(), drawView.getDrawingCache(),
                        UUID.randomUUID().toString()+".png", "drawing");

在清单中我有

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

Answer 1

您必须在Manifest fie上写入存储权限。

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <!-- The above 3 meta tags *must* come first in the head; any other head content must come *after* these tags -->
  <meta name="description" content="">
  <meta name="author" content="">
  <link rel="icon" href="assets/favicon.ico">

  <title>AngularVenkat</title>

  <%= stylesheet_link_tag "application", media: "all", "data-turbolinks-track" => true %>
  <%= javascript_include_tag "application", "data-turbolinks-track" => true %>

  <%= csrf_meta_tags %>


  <!--<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.6/angular.min.js"></script>-->
</head>
<body>

<%= yield %>

</body>
</html>

同样对于Marshmallow，您必须编写用于检查和授予存储权限的代码。

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

如果您需要获得许可，则以下代码可以正常运行。

if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
            == PackageManager.PERMISSION_GRANTED) {
        Log.v(TAG,"Permission is granted");
        return true;
  }

结果回拨权限将是。

ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CODE);

Answer 2

你可以像这样包装你的代码：

 //check permission is granted or no    
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) 
     {
      requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, RESULT);
     } 
    else
     {
    //your code
     }

SecurityException权限 - 不保存图像到Android设备

2 个答案: