我使用android studio转换为网站到android应用，如何连接蓝牙打印机，请帮助我
这是我的MainActivity.java代码
import android.annotation.SuppressLint;
import android.content.pm.PackageManager;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.webkit.GeolocationPermissions;
import android.webkit.WebChromeClient;
import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.view.KeyEvent;
import android.view.View;
import android.Manifest;
import android.app.Activity;
import android.content.res.Configuration;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.webkit.ValueCallback;
import android.widget.Toast;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MainActivity extends ActionBarActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private WebView myWebView;
private WebSettings webSettings;
// attachment
private String mCM;
private ValueCallback<Uri> mUM;
private ValueCallback<Uri[]> mUMA;
private final static int FCR=1;
// attachment
//lolipop
private static final int REQUEST_CODE_PERMISSION = 1;
String mPermission = Manifest.permission.ACCESS_FINE_LOCATION;
//loloipop
//attachments
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent){
super.onActivityResult(requestCode, resultCode, intent);
if(Build.VERSION.SDK_INT >= 21){
Uri[] results = null;
//Check if response is positive
if(resultCode== Activity.RESULT_OK){
if(requestCode == FCR){
if(null == mUMA){
return;
}
if(intent == null){
//Capture Photo if no image available
if(mCM != null){
results = new Uri[]{Uri.parse(mCM)};
}
}else{
String dataString = intent.getDataString();
if(dataString != null){
results = new Uri[]{Uri.parse(dataString)};
}
}
}
}
mUMA.onReceiveValue(results);
mUMA = null;
}else{
if(requestCode == FCR){
if(null == mUM) return;
Uri result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
mUM.onReceiveValue(result);
mUM = null;
}
}
}
@SuppressLint({"SetJavaScriptEnabled", "WrongViewCast"})
//attachments
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//attachments
if(Build.VERSION.SDK_INT >=23 && (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)) {
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA, Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 1);
}
//attachments
myWebView = (WebView) findViewById(R.id.webView);
//attachment
assert myWebView != null;
//attachments
webSettings = myWebView.getSettings();
myWebView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
myWebView.getSettings().setBuiltInZoomControls(true);
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.getSettings().setGeolocationEnabled(true);
myWebView.getSettings().setAppCacheEnabled(true);
myWebView.getSettings().setDatabaseEnabled(true);
myWebView.getSettings().setDomStorageEnabled(true);
webSettings.setGeolocationEnabled(true);
if(Build.VERSION.SDK_INT >= 21){
webSettings.setMixedContentMode(0);
myWebView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
}else if(Build.VERSION.SDK_INT >= 19){
myWebView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
}else if(Build.VERSION.SDK_INT < 19){
myWebView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
myWebView.setWebViewClient(new Callback());
myWebView.loadUrl("http://www.youneeds.in/login.php");
myWebView.setWebChromeClient(new WebChromeClient() {
//attachments
//For Android 3.0+
public void openFileChooser(ValueCallback<Uri> uploadMsg){
mUM = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
MainActivity.this.startActivityForResult(Intent.createChooser(i,"File Chooser"), FCR);
}
// For Android 3.0+, above method not supported in some android 3+ versions, in such case we use this
public void openFileChooser(ValueCallback uploadMsg, String acceptType){
mUM = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
MainActivity.this.startActivityForResult(
Intent.createChooser(i, "File Browser"),
FCR);
}
//For Android 4.1+
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture){
mUM = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), MainActivity.FCR);
}
//For Android 5.0+
public boolean onShowFileChooser(
WebView webView, ValueCallback<Uri[]> filePathCallback,
WebChromeClient.FileChooserParams fileChooserParams){
if(mUMA != null){
mUMA.onReceiveValue(null);
}
mUMA = filePathCallback;
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if(takePictureIntent.resolveActivity(MainActivity.this.getPackageManager()) != null){
File photoFile = null;
try{
photoFile = createImageFile();
takePictureIntent.putExtra("PhotoPath", mCM);
}catch(IOException ex){
Log.e(TAG, "Image file creation failed", ex);
}
if(photoFile != null){
mCM = "file:" + photoFile.getAbsolutePath();
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
}else{
takePictureIntent = null;
}
}
Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
contentSelectionIntent.setType("*/*");
Intent[] intentArray;
if(takePictureIntent != null){
intentArray = new Intent[]{takePictureIntent};
}else{
intentArray = new Intent[0];
}
Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
startActivityForResult(chooserIntent, FCR);
return true;
}
//attachments
@Override
public void onGeolocationPermissionsShowPrompt(String origin, GeolocationPermissions.Callback callback) {
callback.invoke(origin, true, false);
}
});
}
//attachments
public class Callback extends WebViewClient{
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl){
myWebView.loadUrl("file:///android_asset/error.html");
}
ProgressDialog progressDialog;
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// If url contains mailto link then open Mail Intent
if (url.contains("mailto:")) {
// Could be cleverer and use a regex
//Open links in new browser
view.getContext().startActivity(
new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
// Here we can open new activity
return true;
} else {
// Stay within this webview and load url
view.loadUrl(url);
return true;
}
}
//Show loader on url load
public void onPageStarted(WebView view, String url, Bitmap favicon) {
// Then show progress Dialog
// in standard case YourActivity.this
if (progressDialog == null) {
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setMessage("Please Wait...");
progressDialog.show();
}
}
// Called when all page resources loaded
public void onPageFinished(WebView view, String url) {
try {
// Close progressDialog
if (progressDialog.isShowing()) {
progressDialog.dismiss();
progressDialog = null;
}
} catch (Exception exception) {
exception.printStackTrace();
}
}
}
// Create an image file
private File createImageFile() throws IOException{
@SuppressLint("SimpleDateFormat") String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "img_"+timeStamp+"_";
File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
return File.createTempFile(imageFileName,".jpg",storageDir);
}
//attachments
@Override
public void onConfigurationChanged(Configuration newConfig){
super.onConfigurationChanged(newConfig);
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
// Check if the key event was the Back button and if there's history
if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
myWebView.goBack();
return true;
}
// If it wasn't the Back key or there's no web page history, bubble up to the default
// system behavior (probably exit the activity)
return super.onKeyDown(keyCode, event);
}
@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 onPrepareOptionsMenu(Menu menu) {
return false;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
return super.onOptionsItemSelected(item);
}
}
这是我的许可
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
我使用android studio转换为网站到android应用程序，如何连接蓝牙打印机，请帮助我，请提供示例代码示例