我想创建一个简单的Android应用程序，其中的按钮可调用Arduino设备上的URL来打开和关闭灯光。打开网页浏览器不是必需的。
我对Android很新，我已经在这里搜索并找到了一些建议，但它们并不适用于我。
也许有人可以让我朝着正确的方向前进？
到目前为止，这是我的代码，当我按下按钮时，没有任何反应。
package de.triscus.arduinoweb;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.view.View.OnClickListener;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class HomeLight extends AppCompatActivity implements OnClickListener {
String msg = "Android : ";
private Button lichterkette1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_light);
lichterkette1 = (Button) findViewById(R.id.Lichterkette1);
lichterkette1.setOnClickListener(this);
}
public void onClick(View v) {
URL url = null;
HttpURLConnection urlConnection = null;
switch (v.getId())
{
case R.id.Lichterkette1:
try {
url = new URL("http://192.168.2.106/?Lichterkette=1");
urlConnection = (HttpURLConnection) url.openConnection();
// urlConnection = (HttpURLConnection) url.openConnection();
Log.d(msg, "Lichterkette1 pressed");
//InputStream in = new BufferedInputStream(urlConnection.getInputStream());
// Log.d(msg, InputStream);
} catch (MalformedURLException e) {
e.printStackTrace();
Log.d(msg, "URL Malformed");
} catch (IOException e) {
e.printStackTrace();
Log.d(msg, "IO exception");
} finally {
urlConnection.disconnect();
Log.d(msg, "Disconnected");
}
}
}
}
这是logcat输出：
03-16 15:19:26.133 9805-9805/? I/art: Late-enabling -Xcheck:jni
03-16 15:19:26.143 9805-9805/? I/art: VMHOOK: rlim_cur : 0 pid:9805
03-16 15:19:26.173 9805-9815/? I/art: Debugger is no longer active
03-16 15:19:26.193 9805-9805/? E/Typeface: SANS_LOC file not found.
03-16 15:19:26.584 9805-9805/? D/Atlas: Validating map...
03-16 15:19:26.684 9805-9835/? I/Adreno-EGL: <qeglDrvAPI_eglInitialize:410>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_LA.AF.1.1_RB1.05.00.02.006.020 - CR771817 ()
OpenGL ES Shader Compiler Version: E031.25.03.06
Build Date: 03/04/15 Wed
Local Branch:
Remote Branch: refs/tags/AU_LINUX_ANDROID_LA.AF.1.1_RB1.05.00.02.006.020
Local Patches: NONE
Reconstruct Branch: NOTHING
03-16 15:19:33.481 9805-9805/de.triscus.arduinoweb D/Android :: Lichterkette1 pressed
03-16 15:19:33.481 9805-9805/de.triscus.arduinoweb D/Android :: Disconnected
03-16 15:19:34.832 9805-9805/de.triscus.arduinoweb D/Android :: Lichterkette1 pressed
03-16 15:19:34.832 9805-9805/de.triscus.arduinoweb D/Android :: Disconnected
提前谢谢
Triscus
P.S。：允许使用互联网/网络
答案 0 :(得分：3)
网络操作/调用无法完成主线程。您需要从另一个线程或异步任务或目标服务
运行它注意：所有UI操作都应该在onPostExecute，onPreExecute上完成
以下代码可以帮助您解决。
public void onClick(View v) {
switch (v.getId())
{
new Lichterkette().execute();
}
}
class Lichterkette extends AsyncTask<String,Void,String>{
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String... params) {
StringBuilder sb=null;
BufferedReader reader=null;
String serverResponse=null;
try {
URL url = new URL("http://192.168.2.106/?Lichterkette=1");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setConnectTimeout(5000);
connection.setRequestMethod("GET");
connection.connect();
int statusCode = connection.getResponseCode();
//Log.e("statusCode", "" + statusCode);
if (statusCode == 200) {
sb = new StringBuilder();
reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
}
connection.disconnect();
if (sb!=null)
serverResponse=sb.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
return serverResponse;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
//All your UI operation can be performed here
System.out.println(s);
}
}
答案 1 :(得分：0)
我将尽可能地回答这个问题，希望它不仅有助于你，还有助于其他人。您要查找的类称为HttpPost或HttpGet。虽然你正在使用的URLConnection也应该工作。 HttpPost和HttpGet 不是ASYNC 所以你可能需要从另一个线程或意图服务运行它。
您可以发送以下
之类的帖子请求HttpPost post = new HttpPost(String.format(<Your URL goes here>));
try {
//Set the header for the http post
post.setHeader("Content-type", "application/x-www-form-urlencoded");
//Set the contents of the http post (JSON FORMAT)
post.setEntity(new StringEntity(<JSON STRING>));
//Send the post and get the response back
HttpClient client = this.createHttpClient();
HttpResponse response = client.execute(post);
//process your response here
} catch (Exception e) {
Log.e(TAG, "Error", e);
}
Http获取大致相同的格式。
这是一种非常直接的方式，可以在不使用浏览器的情况下发送get和post请求。唯一的问题是，他们不是异步，就像我之前提到的那样，但它非常重要。他们与任何休息api一起工作。所以唯一的问题是你需要确保你的Arduino表现得像一个合适的网络服务器。