如何使用webview下载文件？ （这个案子很奇怪）

Question

我想使用webview从网站下载文件（例如.mp3） 但问题是每当我点击链接时，它会打开浏览器（默认一个） 在它关闭之前会出现一秒钟。并没有下载文件。

这是我的代码，

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.webkit.WebChromeClient;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.DownloadListener;
import android.widget.Button;
import android.widget.TextView;

public class Main extends Activity {
WebView webview;
Button bt_search;
TextView txt_search;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    webview = (WebView) findViewById(R.id.webView);
    webview.setWebChromeClient(new WebChromeClient());
    webview.getSettings().setJavaScriptEnabled(true);
    webview.setDownloadListener(new DownloadListener() {
        public void onDownloadStart(String url, String userAgent,
            String contentDisposition, String mimetype,
            long contentLength) {
          Intent i = new Intent(Intent.ACTION_VIEW);
          i.setData(Uri.parse(url));
          startActivity(i);
        }
    });
    txt_search = (TextView) findViewById(R.id.song);
    webview.loadUrl("http://www.google.com");
    bt_search = (Button) findViewById(R.id.findit);
    bt_search.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            String keyword = txt_search.getText().toString().trim();
            if (!keyword.equals("")) {
                webview.loadUrl("MP3 Sites" + keyword + ".html");
     }
    }
});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

    }

Answer 1

实施WebViewClient以与WebView一起使用。在其中，覆盖shouldOverrideUrlLoading方法，您应该检查它是否是mp3文件，然后将该URL传递给DownloadManager或您用于实际下载文件的任何内容。 这是一个粗略的想法：

    // This will handle downloading. It requires Gingerbread, though
    final DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);

    // This is where downloaded files will be written, using the package name isn't required
    // but it's a good way to communicate who owns the directory
    final File destinationDir = new File (Environment.getExternalStorageDirectory(), getPackageName());
    if (!destinationDir.exists()) {
        destinationDir.mkdir(); // Don't forget to make the directory if it's not there
    }
    webView.setWebViewClient(new WebViewClient() {
        @Override
        public boolean shouldOverrideUrlLoading (WebView view, String url) {
            boolean shouldOverride = false;
            // We only want to handle requests for mp3 files, everything else the webview
            // can handle normally
            if (url.endsWith(".mp3")) {
                shouldOverride = true;
                Uri source = Uri.parse(url);

                // Make a new request pointing to the mp3 url
                DownloadManager.Request request = new DownloadManager.Request(source);
                // Use the same file name for the destination
                File destinationFile = new File (destinationDir, source.getLastPathSegment());
                request.setDestinationUri(Uri.fromFile(destinationFile));
                // Add it to the manager
                manager.enqueue(request);
            }
            return shouldOverride;
        }
    });

Answer 2

if(mWebview.getUrl().contains(".mp3") {
 Request request = new Request(
                        Uri.parse(url));
                request.allowScanningByMediaScanner();
                request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
                request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "download"); 
// You can change the name of the downloads, by changing "download" to everything you want, such as the mWebview title...
                DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
                dm.enqueue(request);        

    }