I heard that Android 3.0 sdk is having support for USB Host. I want to read / write data on USB port of Android device using android app. This app will send data to a sensor device connected to usb port of android tablet. Is there any sample code or example available for USB read write ?
Android – How to access usb port with Android 3.0 sdk
androidusb
Related Solutions
Here's what I created to hold the images that my app is currently displaying. Please note that the "Log" object in use here is my custom wrapper around the final Log class inside Android.
package com.wilson.android.library;
/*
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
*/
import java.io.IOException;
public class DrawableManager {
private final Map<String, Drawable> drawableMap;
public DrawableManager() {
drawableMap = new HashMap<String, Drawable>();
}
public Drawable fetchDrawable(String urlString) {
if (drawableMap.containsKey(urlString)) {
return drawableMap.get(urlString);
}
Log.d(this.getClass().getSimpleName(), "image url:" + urlString);
try {
InputStream is = fetch(urlString);
Drawable drawable = Drawable.createFromStream(is, "src");
if (drawable != null) {
drawableMap.put(urlString, drawable);
Log.d(this.getClass().getSimpleName(), "got a thumbnail drawable: " + drawable.getBounds() + ", "
+ drawable.getIntrinsicHeight() + "," + drawable.getIntrinsicWidth() + ", "
+ drawable.getMinimumHeight() + "," + drawable.getMinimumWidth());
} else {
Log.w(this.getClass().getSimpleName(), "could not get thumbnail");
}
return drawable;
} catch (MalformedURLException e) {
Log.e(this.getClass().getSimpleName(), "fetchDrawable failed", e);
return null;
} catch (IOException e) {
Log.e(this.getClass().getSimpleName(), "fetchDrawable failed", e);
return null;
}
}
public void fetchDrawableOnThread(final String urlString, final ImageView imageView) {
if (drawableMap.containsKey(urlString)) {
imageView.setImageDrawable(drawableMap.get(urlString));
}
final Handler handler = new Handler() {
@Override
public void handleMessage(Message message) {
imageView.setImageDrawable((Drawable) message.obj);
}
};
Thread thread = new Thread() {
@Override
public void run() {
//TODO : set imageView to a "pending" image
Drawable drawable = fetchDrawable(urlString);
Message message = handler.obtainMessage(1, drawable);
handler.sendMessage(message);
}
};
thread.start();
}
private InputStream fetch(String urlString) throws MalformedURLException, IOException {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet request = new HttpGet(urlString);
HttpResponse response = httpClient.execute(request);
return response.getEntity().getContent();
}
}
You can force Android to hide the virtual keyboard using the InputMethodManager, calling hideSoftInputFromWindow
, passing in the token of the window containing your focused view.
// Check if no view has focus:
View view = this.getCurrentFocus();
if (view != null) {
InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
}
This will force the keyboard to be hidden in all situations. In some cases, you will want to pass in InputMethodManager.HIDE_IMPLICIT_ONLY
as the second parameter to ensure you only hide the keyboard when the user didn't explicitly force it to appear (by holding down the menu).
Note: If you want to do this in Kotlin, use:
context?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
Kotlin Syntax
// Only runs if there is a view that is currently focused
this.currentFocus?.let { view ->
val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager
imm?.hideSoftInputFromWindow(view.windowToken, 0)
}
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Best Answer
Try the MissleLauncher example at http://developer.android.com/resources/samples/USB/MissileLauncher/index.html.
Implements very simple async transfer of data. Clear, concise code.