使用Android默认下载器下载文件

Question

我使用的Android 2.2，如何使用Android默认下载器下载文件?（网页浏览器也使用这个下载器）。
我使用如下的代码实现：

Intent i = new Intent(Intent.ACTION_VIEW , Uri.parse("MyUrl"));
startActivity(i);

还有没有更好的实现方法？

Answer 1

import android.app.Activity;
import android.app.DownloadManager;
import android.app.DownloadManager.Query;
import android.app.DownloadManager.Request;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;

public class DownloadManagerActivity extends Activity {
    private long enqueue;
    private DownloadManager dm;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        BroadcastReceiver receiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();
                if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(action)) {
                    long downloadId = intent.getLongExtra(
                            DownloadManager.EXTRA_DOWNLOAD_ID, 0);
                    Query query = new Query();
                    query.setFilterById(enqueue);
                    Cursor c = dm.query(query);
                    if (c.moveToFirst()) {
                        int columnIndex = c
                                .getColumnIndex(DownloadManager.COLUMN_STATUS);
                        if (DownloadManager.STATUS_SUCCESSFUL == c
                                .getInt(columnIndex)) {

                            ImageView view = (ImageView) findViewById(R.id.imageView1);
                            String uriString = c
                                    .getString(c
                                            .getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
                            view.setImageURI(Uri.parse(uriString));
                        }
                    }
                }
            }
        };

        registerReceiver(receiver, new IntentFilter(
                DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }

    public void onClick(View view) {
        dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
        Request request = new Request(
                Uri.parse("url for file to download"));
        enqueue = dm.enqueue(request);

    }

    public void showDownload(View view) {
        Intent i = new Intent();
        i.setAction(DownloadManager.ACTION_VIEW_DOWNLOADS);
        startActivity(i);

}
}
别忘记在manifest中添加android.permission.internet.