Android下载网络图片到本地

第一步，需要添加授权

 <uses-permission android:name="android.permission.INTERNET" />
 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"
        android:maxSdkVersion="32" />
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
        android:maxSdkVersion="32"
        tools:ignore="ScopedStorage" />

第二步：网络请求网络图片地址

   val imageUrl = "https://static.jikecrm.com/2018-06-10/152862233429525.jpg"
               val client = OkHttpClient()
               val request = Request.Builder()
                   .url(imageUrl)
                   .build()
               val call = client.newCall(request)

               call.enqueue(object: Callback {
                   override fun onFailure(call: Call, e: IOException) {
                       Log.e("TAG", "onFailure: 下载失败：${e.message}", )
                   }

                   override fun onResponse(call: Call, response: Response) {
                       if(response.isSuccessful){
                           val inputStream = response.body?.byteStream() ?: return
                           DownLoadImage().saveImage(inputStream,context)
                       }else{
                           Log.e("TAG", "onResponse: 下载失败~~~~~~~", )
                       }
                   }
               })

在协程中去请求，不要在UI主线程请求。

第三步保存图片到本地

    fun saveImage(inputStream: InputStream, context: Context) {

        val values = ContentValues().apply {
            put(MediaStore.Images.Media.DISPLAY_NAME, "tj_${System.currentTimeMillis()}.jpg") // 图片文件名
            put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg") // 图片MIME类型
            put(MediaStore.Images.Media.RELATIVE_PATH, Environment.DIRECTORY_PICTURES) // 存储目录，此处为Pictures
        }

        val uri = context.contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
        if (uri == null) {
            // 创建文件失败，处理错误
            Log.e("DownLoad", "saveImage: 创建文件失败")
            return
        }

        try {
            val fos = context.contentResolver.openOutputStream(uri, "w") ?: return
            val buffer = ByteArray(4 * 1024)
            var read: Int
            while (inputStream.read(buffer).also { read = it } != -1) {
                fos.write(buffer, 0, read)
            }
            fos.close()
            inputStream.close()

            // 更新媒体数据库，使图片在系统相册中可见
            MediaScannerConnection.scanFile(
                context,
                arrayOf(Environment.DIRECTORY_PICTURES),
                null,
                null
            )
            Log.i("DownLoad", "saveImage: 保存成功~~~")
        } catch (e: Exception) {
            context.contentResolver.delete(uri, null, null)
            Log.e("DownLoad", "saveImage: 保存失败：${e.message}")
        }
    }

如果是同一张网络图片，系统默认是覆盖的。