Android kotlin language implements a solution to delete files

1. Preface

During project development, especially projects that require cross-platform collaboration, the operation of deleting user-specified files is particularly important. However, in Android11+ operating systems, permission declarations become complicated, and most solutions are mostly Java language, and there are very few solutions for kotlin language, and most solutions are useless.

I also found this solution that I have tried to put together after many days of success. Here I provide a template for the majority of developers. Comrades can rewrite it based on this template to reduce unnecessary query of information.

2. Applicable environment

Language: kotlin

Operating system version: Android 7+ (This solution has distinguished Android 11+ and Android 7-10, so you can use it with confidence)

3. Template content

1. Authorization application

First, you must register these three permissions:

<uses-permission android:name=".READ_EXTERNAL_STORAGE" />
<uses-permission android:name=".WRITE_EXTERNAL_STORAGE" />
<uses-permission
        android:name=".MANAGE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />

The complete example is as follows:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:andro
    xmlns:tools="/tools">
    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="" />
                <category android:name="" />
            </intent-filter>
        </activity>
    </application>
    <uses-permission android:name=".READ_EXTERNAL_STORAGE" />
    <uses-permission android:name=".WRITE_EXTERNAL_STORAGE" />
    <uses-permission
        android:name=".MANAGE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />
</manifest>

Template in

I wrote comments in the template according to the steps. After copying and leaving, the developers digest them according to the comment process and then simply rewrite them.

The complete template () is as follows:

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class MainActivity : AppCompatActivity() {
    /**
      * 1. Define the common variable of the selector
      *
      * This global variable is defined because it must be registered when onCreate.
      * Cannot register now
      */
    private lateinit var filePickerLauncher: &lt;Intent&gt;
    private var onFilePicked: ((String) -&gt; Unit)? = null
    /**
      * Define the public variables that target file path
      */
    private var sourceFilePath: String? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        (savedInstanceState)
        enableEdgeToEdge()
        setContentView(.activity_main)
        (findViewById()) { v, insets -&gt;
            val systemBars = (())
            (, , , )
            insets
        }
        /**
          * 5. Register file selector
          */
        filePickerLauncher =
            registerForActivityResult(()) { result -&gt;
                if ( == Activity.RESULT_OK) {
                    val uri: Uri? = ?.data
                    if (uri != null) {
                        ("Select File", "Selected file URI: $uri")
                        onFilePicked?.invoke(()) // ✅ Return directly to `Uri`                        deleteFileByUri(uri) // ✅ Use `Uri` to delete it directly                        ("Select File", "Execution ends")
                    } else {
                        (this, "Cannot get file", Toast.LENGTH_SHORT).show()
                    }
                } else {
                    (this, "File not selected", Toast.LENGTH_SHORT).show()
                }
            }
        val testButton2: MaterialButton = findViewById(.testButton2)
         {
            /**
              * 6. Call
              */
            if (checkAndRequestPermissions()) {
                pickFile()
            }
        }
    }
    /**
      * 2. Define the file selector activation function
      */
    private fun pickFile() {
        (Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
            addCategory(Intent.CATEGORY_OPENABLE)
            type = "*/*"
         })
     }
     /**
      * 3. Define URI parsing function
      */
    private fun getFilePathFromUri(uri: Uri): String? {
        val context = applicationContext
        var filePath: String? = null
        if ( == "content") {
            val projection = arrayOf()
            (uri, projection, null, null, null)?.use { cursor -&gt;
                if (()) {
                    val columnIndex =
                        ()
                    filePath = (columnIndex)
                }
            }
        }
        return filePath
    }
    /**
      * 4. Define file deletion function
      */
    private fun deleteFileByUri(uri: Uri) {
        try {
            if (.SDK_INT &gt;= Build.VERSION_CODES.Q) {
                // ✅ Android 10+ requires `()`                val deleted = (contentResolver, uri)
                if (deleted) {
                    ("Delete File", "File deletion successfully: $uri")
                    (this, "File deletion succeeded", Toast.LENGTH_SHORT).show()
                } else {
                    ("Delete File", "File deletion failed: $uri")
                    (this, "Cannot delete file", Toast.LENGTH_SHORT).show()
                }
            } else {
                // ✅ Android 9 and below, try to convert to file path                val filePath = getFilePathFromUri(uri)
                if (filePath != null) {
                    val file = File(filePath)
                    if (() &amp;&amp; ()) {
                        ("Delete File", "File deletion successfully: $filePath")
                        (this, "File deletion succeeded", Toast.LENGTH_SHORT).show()
                    } else {
                        ("Delete File", "File deletion failed: $filePath")
                        (this, "Cannot delete file", Toast.LENGTH_SHORT).show()
                    }
                } else {
                    (this, "Cannot get file path, try to delete it manually", Toast.LENGTH_SHORT).show()
                }
            }
        } catch (e: Exception) {
            ()
            (this, "An error occurred when deleting a file: ${}", Toast.LENGTH_SHORT).show()
        }
    }
}

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