[移动开发]近段时间的学习碎片整理（11）

1、麦克风的音量实时展示

效果图如下

引入依赖

implementation 'com.github.giswangsj:AndRatingBar:1.0.4'

布局如下

<per.wsj.library.AndRatingBar
        android:id="@+id/vrb_volume"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="@id/pb_7"
        app:layout_constraintBottom_toBottomOf="@id/pb_7"
        app:layout_constraintStart_toEndOf="@id/tv_rest_time"
        app:layout_constraintEnd_toStartOf="@id/tv_submit"
        android:paddingStart="20dp"
        android:paddingEnd="20dp"
        android:paddingTop="13dp"
        android:paddingBottom="13dp"
        android:numStars="20"
        app:bgDrawable="@drawable/drawable_voice_off"
        app:starDrawable="@drawable/drawable_voice_on"
        app:keepOriginColor="true"
        android:visibility="gone"
        />

两个drawable都是白色?只是颜色的透明度不一样

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape
            android:shape="rectangle">
            <solid android:color="#2Effffff"/>
            <corners
                android:radius="10dp"
                />
            <size android:width="4dp" android:height="22dp"/>
        </shape>
    </item>
</layer-list>

随后在麦克风的音量回调函数中设置控件的rating即可

2、使用retrofit进行文件下载

@Streaming
    @GET
    fun download(@Url url:String): Call<ResponseBody>

private fun download(downloadUrl: String, savePath: String, callback: DownloadCallback) {
        val saveFile = File(savePath)
        val handler = Handler(Looper.getMainLooper())
        val call = mService.download(downloadUrl)
        call.enqueue(object : retrofit2.Callback<ResponseBody>{
            override fun onResponse(call: Call<ResponseBody>, response: Response<ResponseBody>) {
                launch(Dispatchers.IO, {
                    if (response.code() != 200) {
                        handler.post {
                            callback.onError("download failure: ${response.code()}")
                        }
                    }
                    var inputStream: InputStream? = null
                    var outputStream: OutputStream? = null
                    try {
                        val responseBody = response.body() ?: return@launch
                        //文件总长度
                        val totalLen = responseBody.contentLength()
                        //当前保存的字节数
                        var curLen = 0
                        //从请求到的结果中获取输入流
                        inputStream = responseBody.byteStream()
                        outputStream = FileOutputStream(saveFile)
                        //缓存数据的数组，用于将数据从输入流写入到输出流
                        val buffer = ByteArray(1024)
                        var bufferLen = 0
                        while (!call.isCanceled && inputStream.read(buffer).also { bufferLen = it } != -1) {
                            outputStream.write(buffer, 0, bufferLen)
                            outputStream.flush()
                            curLen += bufferLen
                            //回调下载进度
                            handler.post {
                                callback.onProgress(curLen.toFloat() / totalLen, totalLen)
                            }
                        }
                        handler.post {
                            callback.onSuccess()
                        }
                    }catch (e: Throwable) {
                        if (BuildConfig.DEBUG) {
                            e.printStackTrace()
                        }
                        handler.post {
                            callback.onError(e.localizedMessage ?: "")
                        }
                    }finally {
                        inputStream?.close()
                        outputStream?.close()
                    }
                }, {it.printStackTrace()})
            }

            override fun onFailure(call: Call<ResponseBody>, t: Throwable) {
                handler.post {
                    callback.onError(t.localizedMessage ?: "")
                }
            }
        })
    }

    interface DownloadCallback {
        fun onSuccess()
        fun onProgress(curLength: Float, totalLength: Long)
        fun onError(msg: String)
    }