首先定义布局文件，及点击事件

public class MainActivity extends Activity {    private final int MSG_HELLO = 0;    private Handler mHandler;    private Button btnSubmit;    private EditText txtUsername, txtPassword;    private TextView loginResult;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        btnSubmit = (Button) findViewById(R.id.btnSubmit);        txtUsername = (EditText) findViewById(R.id.username);        txtPassword = (EditText) findViewById(R.id.password);        loginResult = (TextView) findViewById(R.id.loginResult);        btnSubmit.setOnClickListener(new OnClickLoginListener());    }    class OnClickLoginListener implements View.OnClickListener {        @Override        public void onClick(View view) {            String username = txtUsername.getText().toString();            String password = txtPassword.getText().toString();            // 登录请求地址            String url = "http://172.16.18.10:8080/Home/Login";            // 参数封装            Map
      
        params = new HashMap
       
        ();            params.put("username",username);            params.put("password",password);            try {                // 请求登录                String result = HttpUtils.postRequest(url, params);                // 讲请求结果转换成 JSON 对象                JSONObject jsonObject = new JSONObject(result);                String message = jsonObject.getString("message");                int status = jsonObject.getInt("status");                // 登录成功                if(status == 1)                {                    Log.i("Login","登录成功！");                    Intent it = new Intent(MainActivity.this, MainActivity2.class);                    Bundle bundle = new Bundle();                    bundle.putString("name", message+",username:"+ username +" password:"+password);                    it.putExtras(bundle);       // it.putExtra(“test”, "mobile”);                   startActivity(it);            // startActivityForResult(it,REQUEST_CODE);                   finish();                }                else                {                    loginResult.setText(message);                }            }            catch (Exception e)            {                e.printStackTrace();            }        }    }}
       
      

HttpUtils 

public class HttpUtils {    /*     * @function HttpPost 请求     * @param params 请求参数     * @return 服务器响应字符串     * @throws Exception     */    public static String postRequest(final String url, final Map
      
        rawParams ) throws  Exception    {        FutureTask
       
         task = new FutureTask
        
         (new Callable
         
          () {            @Override            public String call() throws Exception {                // 创建一个默认的HTTP客户端                DefaultHttpClient httpClient = new DefaultHttpClient();                // 创建 HttpPost 对象                HttpPost post = new HttpPost(url);                // 如果传递参数个数比较多，可以对传递的参数进行封装                List
          
            params = new ArrayList
           
            (); for (String key : rawParams.keySet()) { // 封装请求参数 params.add(new BasicNameValuePair(key,rawParams.get(key))); } // 设置请求参数 post.setEntity(new UrlEncodedFormEntity(params, "gbk")); // 发送 POST 请求 HttpResponse httpResponse = httpClient.execute(post); // 如果服务器成功地返回响应 if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) { String result = EntityUtils.toString(httpResponse.getEntity()); return result; } return null; } }); new Thread(task).start(); return task.get(); } /* * @function 下载一个图片 * @param imgPath 图片下载地址 * @return Bitmap 对象 * @throws Exception */ public static Bitmap DownloadImage(String imgPath) throws Exception { Bitmap bitmap = null; HttpClient httpClient = new DefaultHttpClient(); HttpGet httpGet = new HttpGet(imgPath); HttpResponse httpResponse = null; try { httpResponse = httpClient.execute(httpGet); if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) { byte[] data = EntityUtils.toByteArray(httpResponse.getEntity()); // 得到一个Bitmap对象，并且为了使其在post内部可以访问，必须声明为final bitmap = BitmapFactory.decodeByteArray(data, 0, data.length); return bitmap; } } catch (Exception e) { e.printStackTrace(); } return bitmap; }}