Question

有人可以告诉我是否可以使用Android设备上的Google云打印进行静音打印？目标是我的应用程序从URL或SD卡中获取文件，然后将其发送到特定的打印机 - 所有这些都不会与任何看到屏幕或触摸任何内容的人进行交互。实际上它将通过蓝牙连接设备上的条形码扫描触发。

由于

Answer 1

嗯，这是可能的，但我不知道为什么在文档中没有太多关于它的信息...

棘手的部分是仅使用Android设备连接到谷歌云打印API（没有第三方服务器，正如文档中解释的那样：https://developers.google.com/cloud-print/docs/appDevGuide），这就是我所做的事情。去解释。

首先，您必须在应用中添加Google登录API，我建议使用firebase API https://firebase.google.com/docs/auth/android/google-signin

然后您必须转到您的Google API控制台：菜单中的https://console.developers.google.com，转到凭据滚动到 OAuth 2.0客户端ID 选择网络客户端（由Google服务自动创建）并将客户端ID 和客户端密钥键保存到您的项目中...在我的项目中，我将其保存为＆＃34;的 gg_client_web_id ＆＃34;和＆＃34; gg_client_web_secret ＆＃34;正如您将在下面的代码中看到的那样。

接下来，我将粘贴所有代码，然后我会解释它：

public class MainActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener { private GoogleApiClient mGoogleApiClient; private FirebaseAuth mAuth; private FirebaseAuth.AuthStateListener mAuthListener; private static final int REQUEST_SINGIN = 1; private TextView txt; public static final String TAG = "mysupertag"; public static final String URLBASE = "https://www.google.com/cloudprint/"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); txt = (TextView) findViewById(R.id.txt); mAuth = FirebaseAuth.getInstance(); // Configure Google Sign In GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN) .requestIdToken(getString(R.string.gg_client_web_id)) .requestEmail() .requestServerAuthCode(getString(R.string.gg_client_web_id)) .requestScopes(new Scope("https://www.googleapis.com/auth/cloudprint")) .build(); mGoogleApiClient = new GoogleApiClient.Builder(this) .enableAutoManage(this /* FragmentActivity */, this /* OnConnectionFailedListener */) .addApi(Auth.GOOGLE_SIGN_IN_API, gso) .build(); findViewById(R.id.sign_in_button).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { signIn(); } }); mAuthListener = new FirebaseAuth.AuthStateListener() { @Override public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) { FirebaseUser user = firebaseAuth.getCurrentUser(); if (user != null) { // User is signed in Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid()); } else { // User is signed out Log.d(TAG, "onAuthStateChanged:signed_out"); } // ... } }; } @Override public void onConnectionFailed(@NonNull ConnectionResult connectionResult) { Log.d(TAG, "error connecting: " + connectionResult.getErrorMessage()); Toast.makeText(this, "error CONN", Toast.LENGTH_LONG).show(); } @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...); if (requestCode == REQUEST_SINGIN) { GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data); if (result.isSuccess()) { // Google Sign In was successful, authenticate with Firebase GoogleSignInAccount account = result.getSignInAccount(); firebaseAuthWithGoogle(account); } else { // Google Sign In failed, update UI appropriately // ... Toast.makeText(this, "error ", Toast.LENGTH_LONG).show(); } } } private void signIn() { Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient); startActivityForResult(signInIntent, REQUEST_SINGIN); } @Override public void onStart() { super.onStart(); mAuth.addAuthStateListener(mAuthListener); } @Override public void onStop() { super.onStop(); if (mAuthListener != null) { mAuth.removeAuthStateListener(mAuthListener); } } private void firebaseAuthWithGoogle(final GoogleSignInAccount acct) { Log.d(TAG, "firebaseAuthWithGoogle:" + acct.getId()); AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null); mAuth.signInWithCredential(credential) .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() { @Override public void onComplete(@NonNull Task<AuthResult> task) { Log.d(TAG, "signInWithCredential:onComplete:" + task.isSuccessful()); // If sign in fails, display a message to the user. If sign in succeeds // the auth state listener will be notified and logic to handle the // signed in user can be handled in the listener. FirebaseUser user = task.getResult().getUser(); txt.setText(user.getDisplayName() + "\n" + user.getEmail());//todo if (!task.isSuccessful()) { Log.w(TAG, "signInWithCredential", task.getException()); Toast.makeText(MainActivity.this, "Authentication failed.", Toast.LENGTH_SHORT).show(); } getAccess(acct.getServerAuthCode()); } }); } private void getPrinters(String token) { Log.d(TAG, "TOKEN: " + token); String url = URLBASE + "search"; Ion.with(this) .load("GET", url) .addHeader("Authorization", "Bearer " + token) .asString() .withResponse() .setCallback(new FutureCallback<Response<String>>() { @Override public void onCompleted(Exception e, Response<String> result) { Log.d(TAG, "finished " + result.getHeaders().code() + ": " + result.getResult()); if (e == null) { Log.d(TAG, "nice"); } else { Log.d(TAG, "error"); } } }); } private void getAccess(String code) { String url = "https://www.googleapis.com/oauth2/v4/token"; Ion.with(this) .load("POST", url) .setBodyParameter("client_id", getString(R.string.gg_client_web_id)) .setBodyParameter("client_secret", getString(R.string.gg_client_web_secret)) .setBodyParameter("code", code) .setBodyParameter("grant_type", "authorization_code") .asString() .withResponse() .setCallback(new FutureCallback<Response<String>>() { @Override public void onCompleted(Exception e, Response<String> result) { Log.d(TAG, "result: " + result.getResult()); if (e == null) { try { JSONObject json = new JSONObject(result.getResult()); getPrinters(json.getString("access_token")); } catch (JSONException e1) { e1.printStackTrace(); } } else { Log.d(TAG, "error"); } } }); }}

正如您所看到的，在onCreate中，重要的一部分是创建GoogleSignInOptions WITH google云打印范围 AND 调用requestIdToken / requestServerAuthCode方法。

然后在 firebaseAuthWithGoogle 方法中调用 getAccess 方法以获取OAuth访问令牌，以便使用Ion库发出所有请求：{{ 3}}

接下来使用access_token，您现在可以对google云打印API发出请求，在这种情况下，我调用 getPrinters 方法，在此方法中我调用＆＃34;搜索＆＃34;方法（来自谷歌云打印API）以获取与登录的谷歌帐户相关联的所有打印机..（要将打印机关联到谷歌帐户，请访问：https://github.com/koush/ion）注意 .addHeader（＆＃34;授权＆＃34;，＆＃34;承载＆＃34; +令牌，这是请求的重要部分，＆＃34;令牌＆＃34; var是access_token，您需要添加此授权标头以便使用API，并且在过期时不要忘记刷新，如下所示：＆{＃3}} 34; 使用刷新令牌＆＃34;一部分。

就是这样，您现在可以打印发送POST请求的内容到＆＃34;提交＆＃34;谷歌云打印API的方法，我建议去这里：https://support.google.com/cloudprint/answer/1686197?hl=en&p=mgmt_classic并查看所有可用的方法以及如何使用它们（参数发送给他们等）。当然，在该链接中解释了＆＃34;提交＆＃34;方法也是。

修改

如何发送请求的示例＆＃34; / submit＆＃34;使用ION LIBRARY和MJSON LIBRARY进行打印（https://developers.google.com/identity/protocols/OAuth2ForDevices）MJSON用于创建JSON对象，您可以按照自己喜欢的方式创建

private void printPdf(String pdfPath, String printerId) { String url = URLBASE + "submit"; Ion.with(this) .load("POST", url) .addHeader("Authorization", "Bearer " + YOUR_ACCESS_TOKEN) .setMultipartParameter("printerid", printerId) .setMultipartParameter("title", "print test") .setMultipartParameter("ticket", getTicket()) .setMultipartFile("content", "application/pdf", new File(pdfPath)) .asString() .withResponse() .setCallback(new FutureCallback<Response<String>>() { @Override public void onCompleted(Exception e, Response<String> result) { if (e == null) { Log.d(TAG, "PRINTTT CODE: " + result.getHeaders().code() + ", RESPONSE: " + result.getResult()); Json j = Json.read(result.getResult()); if (j.at("success").asBoolean()) { Toast.makeText(MainActivity.this, "Success", Toast.LENGTH_LONG).show(); } else { Toast.makeText(MainActivity.this, "ERROR", Toast.LENGTH_LONG).show(); } } else { Toast.makeText(MainActivity.this, "ERROR", Toast.LENGTH_LONG).show(); Log.d(TAG, e.toString()); } } }); } private String getTicket() { Json ticket = Json.object(); Json print = Json.object(); ticket.set("version", "1.0"); print.set("vendor_ticket_item", Json.array()); print.set("color", Json.object("type", "STANDARD_MONOCHROME")); print.set("copies", Json.object("copies", 1)); ticket.set("print", print); return ticket.toString(); }

Answer 2

是的，你可以使用这个REST API（ https://www.google.com/cloudprint/submit ）实现静默打印，我已经使用WCF服务完成了。你需要从url下载内容作为base64内容，然后添加

contentType=dataUrl

在请求中。这是代码..

                postData = "printerid=" + PrinterId;
                postData += "&title=" + JobTitle;
                postData += "&ticket=" + ticket;
                postData += "&content=data:" + documentContent.ContentType + ";base64," + documentContent.Base64Content;
                postData += "&contentType=dataUrl";
                postData += "&tag=test";

然后，请以这种方式请求提交REST API。

     var request = (HttpWebRequest)WebRequest.Create("https://www.google.com/cloudprint/submit");
     var data = Encoding.ASCII.GetBytes(postData);
            request.Headers.Add("Authorization: Bearer " + Token);
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            request.ContentLength = data.Length;
            request.UseDefaultCredentials = true;

            using (var stream = request.GetRequestStream())
            {
                stream.Write(data, 0, data.Length);
            }
            var response = (HttpWebResponse)request.GetResponse();
            string responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
            JavaScriptSerializer json_serializer = new JavaScriptSerializer();
            PrintJobResponse printInfo = json_serializer.Deserialize<PrintJobResponse>(responseString);
            return printInfo;

感谢。

Answer 3

对于现在阅读此内容的任何人来说，经过大量的搜索后，我发现设置只是使用Zapier抓住一个钩子并打印到谷歌云打印更容易，更快（至少来自cordova，我可以＆＃39;代表本机应用程序）

从没有对话框的Android谷歌云打印

3 个答案: