Android 如何使用 Glide 将图像下载到设备内部存储

1. 添加Okhttp依赖项

首先，您需要对应用程序gradle具有okhttp依赖性:

implementation("com.squareup.okhttp3:okhttp:4.10.0")

Note:如果您正在进行改装，则无需添加okhttp依赖项

2. 创建下载功能

好的，现在我们要在视图模型中添加下载逻辑，在视图模型中添加okhttp实例声明和下载功能:

Note:您可以将下载逻辑移动到存储库或任何您想要的地方，这取决于您.

class YourViewModel : ViewModel() {

    // add okhttp instance to your view model or you inject it with hilt if your using dependency injection
    private val okHttpClient = OkHttpClient.Builder().build()

    // add this function to your view model
    fun downloadImage(imageUrl: String) {
        val request = Request.Builder()
            .url(imageUrl)
            .build()

        okHttpClient.newCall(request).enqueue(object : Callback {
            override fun onFailure(call: Call, e: IOException) {
                // Download Failed, you can show error to the user
            }

            override fun onResponse(call: Call, response: Response) {
                if (!response.isSuccessful) {
                    // Download Failed, you can show error to the user
                    return
                }

                response.body?.let { responseBody ->
                    try {
                        // Convert response body to byte array
                        val imageByteArray = responseBody.byteStream().readBytes()

                        // Split image url so we can get the image name
                        val words = imageUrl.split("/").toTypedArray()

                        // Get the image name
                        val imageName = words.last()

                        // Init pathName (Downloads Directory)
                        val pathName = "${Environment.getExternalStorageDirectory()}/${Environment.DIRECTORY_DOWNLOADS}"

                        // Create New file for the image
                        val file = File(pathName, imageName)

                        // Set byteArray To Image File
                        file.writeBytes(imageByteArray)
                    } catch(e: IOException) {
                        // Saving Image Failed, you can show error to the user
                        e.printStackTrace()
                    }
                }
            }
        })
    }

}

3. 将下载功能从片段传递到适配器

现在，您需要将下载函数传递给lambda函数中的适配器，片段中的适配器创建应如下所示:

val adapter = AbstractAdapter(
    context = requireContext(),
    natureList = natureList, // your list here
    downloadImage = { imageUrl ->
        viewModel.downloadImage(imageUrl)
    }
)

适配器构造函数如下所示:

class AbstractAdapter(
    private val mContext: Context, 
    private val natureList: ArrayList<Nature>,
    private val downloadImage: (imageUrl: String) -> Unit
): RecyclerView.Adapter<AbstractAdapter.ViewHolder>()

4. 在downloadBtn中调用downloadImage lambda单击侦听器

现在，我们将在click侦听器中添加downloadImage调用

holder.downloadBtn.setOnClickListener {
    val imageUrl = natureList[position].space
    imageUrl?.let {
        downloadImage(it)
    }
}

5. 将写外部存储权限添加到AndroidManifest.xml

将此权限添加到您的AndroidManifest.xml文件，可将文件添加到手机存储中

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
        android:maxSdkVersion="28" />

Note:此权限仅适用于sqk版本<；=28所以我们加了android:maxSdkVersion="28"

我希望一切都很清楚.