如何在下载完成时获得通知

Question

我的android应用程序中有一个下载功能，当我下载一个文件时，它会通过toast通知我。我想知道如何有一个敬酒通知时，下载完成。我已经尝试了其他建议，但都没有达到我所期望的结果。

这是下载代码。

webView.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String userAgent, String contentDisposition,
String mimeType, long contentLength) {
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
request.setMimeType(mimeType);
String cookies = CookieManager.getInstance().getCookie(url);
request.addRequestHeader("cookie",cookies);
request.addRequestHeader("User-Agent",userAgent);
request.setDescription("Downloading File");
request.setTitle(URLUtil.guessFileName(url,contentDisposition,mimeType));
request.allowScanningByMediaScanner();
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,
URLUtil.guessFileName(url, contentDisposition, mimeType));
DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
downloadManager.enqueue(request);
Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_SHORT).show();
}
});

提前谢谢你。

Answer 1

您可以创建一个Broadcast Receiver来处理任何已完成下载的文件:

主要活动

public class MainActivity extends AppCompatActivity {
// create an object
OnComplete onComplete ;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WebView webView = null;
webView.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String userAgent, String contentDisposition,
String mimeType, long contentLength) {
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
request.setMimeType(mimeType);
String cookies = CookieManager.getInstance().getCookie(url);
request.addRequestHeader("cookie",cookies);
request.addRequestHeader("User-Agent",userAgent);
request.setDescription("Downloading File");
request.setTitle(URLUtil.guessFileName(url,contentDisposition,mimeType));
request.allowScanningByMediaScanner();
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,
URLUtil.guessFileName(url, contentDisposition, mimeType));
DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
downloadManager.enqueue(request);
Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_SHORT).show();
}
});
// the broadcast receiver object
onComplete = new OnComplete();
}
@Override
protected void onResume() {
super.onResume();
// to start handling any download that completes
registerReceiver(onComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
}
@Override
protected void onPause() {
super.onPause();
// to stop handling download complete when exit app
unregisterReceiver(onComplete);
}
}

广播接收器(OnComplete)

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
public class OnComplete extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
// these codes will run when download completed
// And you can do some thing
}
}

，请不要忘记在<application/>标签的Mainfest.xml中添加这个

<receiver android:name=".OnComplete" />

Answer 2

感谢@a7d。

我已经简化了答案，所以我不需要创建新的Java类(OnComplete)，因此不需要将其添加到Manifest.XML。

我只需要在webView中添加一行代码。setDownloadListener并在WebView类中创建新的BroadcastReceiver

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
webView.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String userAgent, String contentDisposition,
String mimeType, long contentLength) {
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
request.setMimeType(mimeType);
String cookies = CookieManager.getInstance().getCookie(url);
request.addRequestHeader("cookie",cookies);
request.addRequestHeader("User-Agent",userAgent);
request.setDescription("Downloading File");
request.setTitle(URLUtil.guessFileName(url,contentDisposition,mimeType));
request.allowScanningByMediaScanner();
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,
URLUtil.guessFileName(url, contentDisposition, mimeType));
DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
//Registering receiver in Download Manager
registerReceiver(onCompleted, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));    
downloadManager.enqueue(request);
Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_SHORT).show();
}
});
...
BroadcastReceiver onCompleted = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context.getApplicationContext(), "Download Finish", Toast.LENGTH_SHORT).show();