Java 如何在webview android中添加下载管理器 package sawatop.com.tubemate； 导入android.app.Activity； 导入android.app.AlertDialog； 导入android.content.Context； 导入android.content.DialogInterface； 导入android.graphics.Bitmap； 导入android.net.ConnectivityManager； 导入android.net.NetworkInfo； 导入android.os.Bundle； 导入android.view.KeyEvent； 导入android.view.view； 导入android.webkit.WebView； 导入android.webkit.WebViewClient； 导入android.widget.Button； 导入android.widget.ProgressBar； 导入android.widget.Toast； 导入com.google.android.gms.ads.AdRequest； 导入com.google.android.gms.ads.AdView； 公共类详细信息活动扩展活动{ 私人ProgressBar ProgressBar； 私有网络视图； 私有WebView web2； 私有字符串url=“”； 私有字符串url2=“”； 私人按钮； 私人长按时间； 私有静态最终整数周期=60000； @凌驾 公共布尔onKeyDown（int-keyCode，KeyEvent事件）{ 如果（event.getKeyCode（）==KeyEvent.KEYCODE_BACK）{ 开关（event.getAction（））{ case KeyEvent.ACTION_向下： 如果（event.getDownTime（）-lastPressedTime

如何从该url添加下载文件

package sawatop.com.tubemate; 
import android.app.Activity; 
import android.app.AlertDialog; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.graphics.Bitmap; 
import android.net.ConnectivityManager; 
import android.net.NetworkInfo; 
import android.os.Bundle; 
import android.view.KeyEvent; 
import android.view.View; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 
import android.widget.Button; 
import android.widget.ProgressBar; 
import android.widget.Toast; 
import com.google.android.gms.ads.AdRequest; 
import com.google.android.gms.ads.AdView; 

public class DetailsActivity extends Activity { 
    private ProgressBar progressBar; 
    private WebView web; 
    private WebView web2; 
    private String url = ""; 
    private String url2 = ""; 
    private Button buttonClose; 
    private long lastPressedTime; 
    private static final int PERIOD = 60000; 

    @Override 
    public boolean onKeyDown(int keyCode, KeyEvent event) { 
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) { 
            switch (event.getAction()) { 
                case KeyEvent.ACTION_DOWN: 
                    if (event.getDownTime() - lastPressedTime < PERIOD) { 
                        finish(); 
                    } else { 
                        Toast.makeText(getApplicationContext(), "click agin to exit", Toast.LENGTH_SHORT).show(); 
                        lastPressedTime = event.getEventTime(); 
                    } return true; 
                } 
            } 
        return false; 
    } 

    @Override 
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_details); 
        AdView mAdView = (AdView) findViewById(R.id.adView); 
        AdRequest adRequest = new AdRequest.Builder().build(); 
        mAdView.loadAd(adRequest); 
        if (getIntent().getExtras() != null) { 
            url = getIntent().getExtras().getString("KEY_INTENT_URL"); 
        } 
        buttonClose = (Button) findViewById(R.id.btnClose);
        buttonClose.setText("\u0623\u063a\u0644\u0627\u0642 \u0627\u0644\u0646\u0627\u0641\u0630\u0629");
        buttonClose.setOnClickListener(new View.OnClickListener() { 
            @Override 
            public void onClick(View v) {
                finish(); 
            } 
        }); 
        progressBar = (ProgressBar) findViewById(R.id.progress); 
        web = (WebView) findViewById(R.id.webview); web2 = (WebView) findViewById(R.id.webview2);
        web2.getSettings().setJavaScriptEnabled(true); 
        web.getSettings().setJavaScriptEnabled(true); 
        if (hasConnection(this)) { 
            web.loadUrl(url);
            web2.loadUrl(url2); 
            web.setWebViewClient(new WebViewClient() { 
                @Override 
                public void onPageStarted(WebView view, String url, Bitmap favicon) { 
                    // TODO Auto-generated method stub 
                    super.onPageStarted(view, url, favicon); 
                    super.onPageStarted(view, url2, favicon); 
                    progressBar.setVisibility(View.VISIBLE); 
                } 

                @Override 
                public void onPageFinished(WebView view, String url) {
                    // TODO Auto-generated method stub 
                    super.onPageFinished(view, url); 
                    super.onPageFinished(view, url2); 
                    progressBar.setVisibility(View.GONE); 
                    // actionBar.show(); 
                } 
            }); 
        } else { 
            DisplayAlertDialog(this, "Internet connection not available. \nPlease check your internet connection."); 
        } 
    } 
    public static boolean hasConnection(Context context) { 
        boolean isNetAvailable = false; 
        if (context != null) { 
            final ConnectivityManager mConnectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); 
        if (mConnectivityManager != null) { 
            boolean mobileNetwork = false; 
            boolean wifiNetwork = false; 
            boolean mobileNetworkConnecetd = false; 
            boolean wifiNetworkConnecetd = false; 
            final NetworkInfo mobileInfo = mConnectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE); 
            final NetworkInfo wifiInfo = mConnectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI); 
            if (mobileInfo != null) { 
                mobileNetwork = mobileInfo.isAvailable(); 
            } 
            if (wifiInfo != null) { 
                wifiNetwork = wifiInfo.isAvailable(); 
            } 
            if (wifiNetwork || mobileNetwork) { 
                if (mobileInfo != null) 
                    mobileNetworkConnecetd = mobileInfo.isConnectedOrConnecting(); 
                wifiNetworkConnecetd = wifiInfo.isConnectedOrConnecting(); 
            } 
            isNetAvailable = (mobileNetworkConnecetd || wifiNetworkConnecetd); 
         } 
      } 
      return isNetAvailable; 
    } 

    private void DisplayAlertDialog(Context context, String Message) {
      AlertDialog.Builder alertDialog = new AlertDialog.Builder(context); 
      alertDialog.setTitle(web.getTitle()); 
      alertDialog.setMessage(Message); 
      alertDialog.setPositiveButton("OK", new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, int which) {
              dialog.dismiss(); 
          } 
      }); 
      alertDialog.show(); 
    } 
}