我在android中有一个简单的应用程序。其中有两个活动。一个是 Document.Activity，布局 xml 是 butt.xml。另一个是带有 print_dialog.xml 的 PrintDialogActivity。我共享我的打印机，一切正常。但是当我选择我的共享打印机并单击谷歌云打印中的打印按钮时，会出现一个带有“缺少文档”的黑色标题栏。现在我能做什么？请帮我..
这是我的文档活动：
public class Document extends Activity{
Button btnprt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.butt);
btnprt = (Button) findViewById(R.id.button1);
btnprt.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent printIntent = new Intent(Document.this, PrintDialogActivity.class);
//File file = new File("/sdcard/StudentLatePass.txt");
//printIntent.setDataAndType(Uri.fromFile(file), "text/*");
Uri docUri = Uri.parse("http://www.google.com");
//String ur = docUri.toString();
printIntent.setDataAndType(docUri, "application/pdf");
printIntent.putExtra("title", "StudentLatePass");
startActivity(printIntent);
}
});
}
}
这是我的 butt.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="114dp"
android:text="Print" />
</RelativeLayout>
这是我的 PrintDialogActivity：
public class PrintDialogActivity extends Activity {
private static final String PRINT_DIALOG_URL = "https://www.google.com/cloudprint /dialog.html";
private static final String JS_INTERFACE = "AndroidPrintDialog";
private static final String CONTENT_TRANSFER_ENCODING = "base64";
private static final String ZXING_URL = "http://zxing.appspot.com";
private static final int ZXING_SCAN_REQUEST = 65743;
/**
* Post message that is sent by Print Dialog web page when the printing dialog
* needs to be closed.
*/
private static final String CLOSE_POST_MESSAGE_NAME = "cp-dialog-on-close";
/**
* Web view element to show the printing dialog in.
*/
private WebView dialogWebView;
/**
* Intent that started the action.
*/
Intent cloudPrintIntent;
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.print_dialog);
dialogWebView = (WebView) findViewById(R.id.webview);
cloudPrintIntent = this.getIntent();
WebSettings settings = dialogWebView.getSettings();
settings.setJavaScriptEnabled(true);
dialogWebView.setWebViewClient(new PrintDialogWebClient());
dialogWebView.addJavascriptInterface(
new PrintDialogJavaScriptInterface(), JS_INTERFACE);
dialogWebView.loadUrl(PRINT_DIALOG_URL);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == ZXING_SCAN_REQUEST && resultCode == RESULT_OK) {
dialogWebView.loadUrl(intent.getStringExtra("SCAN_RESULT"));
}
}
final class PrintDialogJavaScriptInterface {
public String getType() {
return cloudPrintIntent.getType();
}
public String getTitle() {
return cloudPrintIntent.getExtras().getString("title");
}
public String getContent() {
try {
ContentResolver contentResolver = getContentResolver();
InputStream is = contentResolver.openInputStream(cloudPrintIntent.getData());
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[4096];
int n = is.read(buffer);
while (n >= 0) {
baos.write(buffer, 0, n);
n = is.read(buffer);
}
is.close();
baos.flush();
return Base64.encodeToString(baos.toByteArray(), Base64.DEFAULT);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return "";
}
public String getEncoding() {
return CONTENT_TRANSFER_ENCODING;
}
public void onPostMessage(String message) {
if (message.startsWith(CLOSE_POST_MESSAGE_NAME)) {
finish();
}
}
}
private final class PrintDialogWebClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (url.startsWith(ZXING_URL)) {
Intent intentScan = new Intent("com.google.zxing.client.android.SCAN");
intentScan.putExtra("SCAN_MODE", "QR_CODE_MODE");
try {
startActivityForResult(intentScan, ZXING_SCAN_REQUEST);
} catch (ActivityNotFoundException error) {
view.loadUrl(url);
}
} else {
view.loadUrl(url);
}
return false;
}
@Override
public void onPageFinished(WebView view, String url) {
if (PRINT_DIALOG_URL.equals(url)) {
// Submit print document.
view.loadUrl("javascript:printDialog.setPrintDocument(printDialog.createPrintDocument("
+ "window." + JS_INTERFACE + ".getType(),window." + JS_INTERFACE + ".getTitle(),"
+ "window." + JS_INTERFACE + ".getContent(),window." + JS_INTERFACE + ".getEncoding()))");
// Add post messages listener.
view.loadUrl("javascript:window.addEventListener('message',"
+ "function(evt){window." + JS_INTERFACE + ".onPostMessage(evt.data)}, false)");
}
}
}
}
这是我的 print_dialog.xml：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<WebView android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>