Android kotlin语言实现删除文件的解决方案

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

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/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/Theme.AbstractFunctionDemo"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission
        android:name="android.permission.MANAGE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />
</manifest>

package com.example.abstractfunctiondemo
import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import android.Manifest
import android.app.Activity
import android.content.ContentUris
import android.content.ContentValues
import android.content.Context
import android.content.Intent
import android.content.pm.PackageManager
import android.provider.Settings
import android.net.Uri
import android.os.Build
import android.os.Environment
import android.provider.DocumentsContract
import android.provider.MediaStore
import android.provider.OpenableColumns
import android.util.Log
import android.widget.Toast
import androidx.activity.result.contract.ActivityResultContracts
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import androidx.documentfile.provider.DocumentFile
import com.google.android.material.button.MaterialButton
import java.io.File
import java.io.FileInputStream
import java.io.FileOutputStream
import java.io.OutputStream
class MainActivity : AppCompatActivity() {
    /**
     * 1.定义选择器的公共变量
     *
     * 定义这个全局变量是因为必须在onCreate的时候就注册，
     * 不可以现用现注册
     */
    private lateinit var filePickerLauncher: androidx.activity.result.ActivityResultLauncher<Intent>
    private var onFilePicked: ((String) -> Unit)? = null
    /**
     * 定义目标文件路径的公共变量
     */
    private var sourceFilePath: String? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
        /**
         * 5.注册文件选择器
         */
        filePickerLauncher =
            registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
                if (result.resultCode == Activity.RESULT_OK) {
                    val uri: Uri? = result.data?.data
                    if (uri != null) {
                        Log.e("选取文件", "选择的文件 URI: $uri")
                        onFilePicked?.invoke(uri.toString()) // ✅ 直接返回 `Uri`
                        deleteFileByUri(uri) // ✅ 直接用 `Uri` 删除
                        Log.e("选取文件", "执行结束")
                    } else {
                        Toast.makeText(this, "无法获取文件", Toast.LENGTH_SHORT).show()
                    }
                } else {
                    Toast.makeText(this, "未选择文件", Toast.LENGTH_SHORT).show()
                }
            }
        val testButton2: MaterialButton = findViewById(R.id.testButton2)
        testButton2.setOnClickListener {
            /**
             * 6.调用
             */
            if (checkAndRequestPermissions()) {
                pickFile()
            }
        }
    }
    /**
     * 2.定义文件选择器激活函数
     */
    private fun pickFile() {
        filePickerLauncher.launch(Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
            addCategory(Intent.CATEGORY_OPENABLE)
            type = "*/*"
        })
    }
    /**
     * 3.定义URI解析函数
     */
    private fun getFilePathFromUri(uri: Uri): String? {
        val context = applicationContext
        var filePath: String? = null
        if (uri.scheme == "content") {
            val projection = arrayOf(MediaStore.Files.FileColumns.DATA)
            context.contentResolver.query(uri, projection, null, null, null)?.use { cursor ->
                if (cursor.moveToFirst()) {
                    val columnIndex =
                        cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATA)
                    filePath = cursor.getString(columnIndex)
                }
            }
        }
        return filePath
    }
    /**
     * 4.定义文件删除函数
     */
    private fun deleteFileByUri(uri: Uri) {
        try {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                // ✅ Android 10+ 需要用 `DocumentsContract.deleteDocument()`
                val deleted = DocumentsContract.deleteDocument(contentResolver, uri)
                if (deleted) {
                    Log.e("删除文件", "文件删除成功: $uri")
                    Toast.makeText(this, "文件删除成功", Toast.LENGTH_SHORT).show()
                } else {
                    Log.e("删除文件", "文件删除失败: $uri")
                    Toast.makeText(this, "无法删除文件", Toast.LENGTH_SHORT).show()
                }
            } else {
                // ✅ Android 9 及以下，尝试转换为文件路径
                val filePath = getFilePathFromUri(uri)
                if (filePath != null) {
                    val file = File(filePath)
                    if (file.exists() && file.delete()) {
                        Log.e("删除文件", "文件删除成功: $filePath")
                        Toast.makeText(this, "文件删除成功", Toast.LENGTH_SHORT).show()
                    } else {
                        Log.e("删除文件", "文件删除失败: $filePath")
                        Toast.makeText(this, "无法删除文件", Toast.LENGTH_SHORT).show()
                    }
                } else {
                    Toast.makeText(this, "无法获取文件路径，尝试手动删除", Toast.LENGTH_SHORT).show()
                }
            }
        } catch (e: Exception) {
            e.printStackTrace()
            Toast.makeText(this, "删除文件出错: ${e.message}", Toast.LENGTH_SHORT).show()
        }
    }
}