java - 如何从webview下载文件

Question

我无法从我的网站下载在 WebView 中加载的文件。单击文件的下载链接后，Web View 会重新加载主页 URL。

我通过一些博客帮助更改了一些代码，但没有改变。还可以帮助编写从网站下载文件的代码。

public class WebPageActivity extends AppCompatActivity {

    private WebView webView;

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_web_page);
        webView = findViewById(R.id.webView);

        // Define url that will open in webview
        String webViewUrl = "http://www.tekies.online";

        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setLoadWithOverviewMode(true);
        webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
        webView.setScrollbarFadingEnabled(false);
        // webView.getSettings().setBuiltInZoomControls(true);
        webView.getSettings().setPluginState(PluginState.ON);
        webView.getSettings().setAllowFileAccess(true);
        webView.getSettings().setSupportZoom(true);

        if(!isConnected(WebPageActivity.this)) buildDialog(WebPageActivity.this).show();
        else {
        webView.loadUrl(webViewUrl);
        startWebView();
            }


        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);
            }
        });
    }

    private void startWebView() {

        webView.setWebViewClient(new WebViewClient() {
            ProgressDialog progressDialog;

            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                if (url.contains("youtube")) {
                    view.getContext().startActivity(
                            new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
                // Open links in External Browser
                    return true;

                } else {
                    // Stay within this webview and load url
                    view.loadUrl(url);
                    return true;
                }

            }


            public void onLoadResource(WebView view, String url) {
                if (progressDialog == null && url.contains("tekies")
                        ) {
                    progressDialog = new ProgressDialog(WebPageActivity.this);
                    progressDialog.setMessage("Loading...");
                    progressDialog.show();
                }
            }
            public void onPageFinished(WebView view, String url) {

                try {
                    // Close progressDialog
                    if (progressDialog.isShowing()) {
                        progressDialog.dismiss();
                        progressDialog = null;
                    }
                } catch (Exception exception) {
                    exception.printStackTrace();
                }
            }

        });

    }

    @Override
    public void onBackPressed() {
        if(webView.canGoBack()) {
            webView.goBack();
        } else {
            super.onBackPressed();
        }
    }

    public boolean isConnected(Context context) {

        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netinfo = cm.getActiveNetworkInfo();

        if (netinfo != null && netinfo.isConnectedOrConnecting()) {
            android.net.NetworkInfo wifi = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
            android.net.NetworkInfo mobile = cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

            if((mobile != null && mobile.isConnectedOrConnecting()) || (wifi != null && wifi.isConnectedOrConnecting())) return true;
            else return false;
        } else
            return false;
    }

    public AlertDialog.Builder buildDialog(Context c) {

        AlertDialog.Builder builder = new AlertDialog.Builder(c);
        Toast.makeText(getApplicationContext(), "Please Connect to Internet", Toast.LENGTH_SHORT).show();
        builder.setMessage("You need to have Mobile Data or wifi to access this. Press ok to connect");

        builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                Intent dialogIntent = new Intent(android.provider.Settings.ACTION_SETTINGS);
                dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(dialogIntent);
            }
        });

        return builder;
    }

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

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch(item.getItemId()) {
            case R.id.menu_item1:
                Intent intent = new Intent(this, settings.class);
                this.startActivity(intent);
                break;
            case R.id.menu_item2:
                // another startActivity, this is for item with id "menu_item2"
                break;
            default:
                return super.onOptionsItemSelected(item);
        }
        return true;
    }
}

必须从 WebView 下载文件。

Answer 1

你可以试试这个

mWebView.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);
}
});

需要在Manifest中添加此权限。

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

继续编码:)