在某些情况下,在上传文件时,我们可能需要从google驱动器中上传文件,或者可能是我们希望向本案的用户提供对google驱动器的某些文件夹访问权限。就像在提供课程或学习资料的情况下一样,我们已经将其存储在Google驱动器中。在这里,我们将实现如何使用Android Studio向用户授予对Google云端硬盘内容的访问权限。下面提供了一个示例视频,以使您对我们在本文中将要做的事情有个大概的了解。注意,我们将使用Java语言实现该项目。
分步实施
步骤1:创建一个新项目
要在Android Studio中创建新项目,请参阅如何在Android Studio中创建/启动新项目。请注意,选择Java作为编程语言。
步骤2:将其添加到AndroidManifest.xml文件中
步骤3:使用activity_main.xml文件
导航到应用程序> res>布局> activity_main.xml,然后将以下代码添加到该文件中。以下是activity_main.xml文件的代码。
XML
Java
import android.app.AlertDialog;
import android.app.DownloadManager;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.webkit.DownloadListener;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// initialising the web view
WebView wv = (WebView) findViewById(R.id.webview);
// add your link here
wv.loadUrl("https://Enter your drive link here");
wv.setWebViewClient(new Client());
WebSettings ws = wv.getSettings();
// Enabling javascript
ws.setJavaScriptEnabled(true);
wv.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
wv.clearCache(true);
wv.clearHistory();
// download manager is a service that can be used to handle downloads
wv.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String s1, String s2, String s3, long l) {
DownloadManager.Request req = new DownloadManager.Request(Uri.parse(url));
req.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
dm.enqueue(req);
Toast.makeText(MainActivity.this, "Downloading....", Toast.LENGTH_SHORT).show();
}
});
}
private class Client extends WebViewClient {
// on page started load start loading the url
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
}
// load the url of our drive
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
}
public void onReceivedError(WebView webView, int errorCode, String description, String failingUrl) {
// if stop loading
try {
webView.stopLoading();
} catch (Exception e) {
}
if (webView.canGoBack()) {
webView.goBack();
}
// if loaded blank then show error
// to check internet connection using
// alert dialog
webView.loadUrl("about:blank");
AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
alertDialog.setTitle("Error");
alertDialog.setMessage("Check your internet connection and Try again.");
alertDialog.setButton(DialogInterface.BUTTON_POSITIVE, "Try Again", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
finish();
startActivity(getIntent());
}
});
alertDialog.show();
super.onReceivedError(webView, errorCode, description, failingUrl);
}
}
}
步骤4:使用MainActivity。 Java文件
转到MainActivity。 Java文件并参考以下代码。下面是MainActivity的代码。 Java文件。在代码内部添加了注释,以更详细地了解代码。
Java
import android.app.AlertDialog;
import android.app.DownloadManager;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.webkit.DownloadListener;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// initialising the web view
WebView wv = (WebView) findViewById(R.id.webview);
// add your link here
wv.loadUrl("https://Enter your drive link here");
wv.setWebViewClient(new Client());
WebSettings ws = wv.getSettings();
// Enabling javascript
ws.setJavaScriptEnabled(true);
wv.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
wv.clearCache(true);
wv.clearHistory();
// download manager is a service that can be used to handle downloads
wv.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String s1, String s2, String s3, long l) {
DownloadManager.Request req = new DownloadManager.Request(Uri.parse(url));
req.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
dm.enqueue(req);
Toast.makeText(MainActivity.this, "Downloading....", Toast.LENGTH_SHORT).show();
}
});
}
private class Client extends WebViewClient {
// on page started load start loading the url
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
}
// load the url of our drive
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
}
public void onReceivedError(WebView webView, int errorCode, String description, String failingUrl) {
// if stop loading
try {
webView.stopLoading();
} catch (Exception e) {
}
if (webView.canGoBack()) {
webView.goBack();
}
// if loaded blank then show error
// to check internet connection using
// alert dialog
webView.loadUrl("about:blank");
AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
alertDialog.setTitle("Error");
alertDialog.setMessage("Check your internet connection and Try again.");
alertDialog.setButton(DialogInterface.BUTTON_POSITIVE, "Try Again", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
finish();
startActivity(getIntent());
}
});
alertDialog.show();
super.onReceivedError(webView, errorCode, description, failingUrl);
}
}
}
输出: