执行 ASyncTask 时加载 ProgressBar

Question

我正在完成一个应用程序，现在我想添加一个进度条或类似 Material 设计加载圆圈的东西。
我将在用户登录时使用它。
LoginActivity 基本上是这样工作的：当用户点击确定按钮时，ASyncTask 从我的 API 获取一些数据。我想要的是在 ASyncTask 查询我的 API 并接收回数据时显示进度条。
我尝试了一些库和一些教程，但没有得到任何结果。
这是我的 LoginActivity：

package com.tumta.henrique.teste.view;

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Color;
import android.os.Build;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;

import com.tumta.henrique.teste.R;
import com.tumta.henrique.teste.model.ConsultaLogin;
import com.tumta.henrique.teste.util.Connectivity;

import java.util.List;

public class LoginActivity extends ActionBarActivity implements ConsultaLogin.ConsultaConcluidaLoginListener {

    EditText txtUsuario, txtSenha;
    ActionBar actionbar;
    Button btnOk, btnCancelar;
    private AlertDialog alerta;
    String login, senha;
    Connectivity conn = new Connectivity();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        if (Build.VERSION.SDK_INT >= 21) {
            Window window = this.getWindow();
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            window.setStatusBarColor(this.getResources().getColor(R.color.azul_nav));
        }
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        txtUsuario = (EditText) findViewById(R.id.edit_usuario);
        txtSenha = (EditText) findViewById(R.id.edit_senha);
        txtUsuario.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            public boolean onEditorAction(TextView v, int actionId,
                                          KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_GO) {
                    txtSenha.requestFocus();
                    return true;
                }
                return false;
            }
        });
        txtSenha.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            public boolean onEditorAction(TextView v, int actionId,
                                          KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_GO) {
                    onClickOk(v);
                    return true;
                }
                return false;
            }
        });
        actionbar = getSupportActionBar();
        actionbar.hide();
        btnOk = (Button) findViewById(R.id.button_ok);
        btnCancelar = (Button) findViewById(R.id.button_cancelar);
        boolean isConnected = conn.isConnected(this);
        if(isConnected == false){
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle("Erro");
            builder.setMessage(R.string.aviso_rede);
            builder.setPositiveButton(R.string.config, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    startActivityForResult(new Intent(android.provider.Settings.ACTION_SETTINGS), 0);
                }
            });
            builder.setNegativeButton("Sair", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    finish();
                }
            });
            alerta = builder.create();
            alerta.show();
        }
    }

    @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_login, menu);
        return true;
    }

    @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();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    public void onClickOk(View view) {
        try {
            if (txtUsuario.getText().toString().equals("") || txtSenha.getText().toString().equals("")) {
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setTitle("Erro");
                builder.setMessage("Preencha todos os campos!");
                builder.setNeutralButton("Ok", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        login = "";
                        senha = "";
                        txtSenha.getText().clear();
                        txtUsuario.requestFocus();
                    }
                });
                alerta = builder.create();
                alerta.show();
            } else {
                login = txtUsuario.getText().toString();
                senha = txtSenha.getText().toString();
                ConsultaLogin.URL_STRING = "http://186.207.85.205:7001/com.henrique.rest/api/v1/status/login?usu_login="
                        + login + "&usu_senha=" + senha;
                new ConsultaLogin(this).execute();
            }
        } catch (Exception e) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle("Erro");
            builder.setMessage("Ocorreu um erro inesperado! \nTente novamente.");
            builder.setNeutralButton("Ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    login = "";
                    senha = "";
                    txtUsuario.getText().clear();
                    txtSenha.getText().clear();
                    txtUsuario.requestFocus();
                }
            });
            alerta = builder.create();
            alerta.show();
        }
    }

    public void onClickCancelar(View view) {
        finish();
    }

    @Override
    public void onConsultaConcluida(List<String> result) {
        if (result.isEmpty()) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle("Erro");
            builder.setMessage("Usuario ou Senha Incorreto!");
            builder.setNeutralButton("Ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    login = "";
                    senha = "";
                    txtSenha.getText().clear();
                    txtUsuario.requestFocus();
                }
            });
            alerta = builder.create();
            alerta.show();
        } else {
            Intent intent = new Intent(this, MainActivity.class);
            startActivity(intent);
        }
    }
}

这是我的 ASyncTask：

package com.tumta.henrique.teste.model;

import android.os.AsyncTask;
import android.util.Log;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by Henrique on 16/06/2015.
 */
public class ConsultaLogin extends AsyncTask<Void, Void, List<String>> {

    private ConsultaConcluidaLoginListener listener;

    //public static String login, senha;
    public static String URL_STRING = "";


    public ConsultaLogin(ConsultaConcluidaLoginListener listener) {
        this.listener = listener;
    }

    @Override
    protected List<String> doInBackground(Void... arg0) {
        try {
            String resultado = ConsultaServidor();
            return InterpretaResultado(resultado);
        } catch (IOException e) {
            Log.e("Erro", "Ocorreu um erro na consulta ao servidor!", e);
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    private List<String> InterpretaResultado(String resultado) throws JSONException {
        JSONObject object = new JSONObject(resultado);
        JSONArray jsonArray = object.getJSONArray("login");
        List<String> listaLogin = new ArrayList<>();
        for (int i = 0; i < jsonArray.length(); i++) {
            JSONObject jsonLogin = jsonArray.getJSONObject(i);
            if (jsonLogin.has("usu_nome")) {
                String nome = jsonLogin.getString("usu_nome");
                listaLogin.add(i, nome);
            } else listaLogin.clear();
        }
        return listaLogin;
    }

    private String ConsultaServidor() throws IOException {
        InputStream is = null;

        try {
            URL url = new URL(URL_STRING);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(10000);
            conn.setReadTimeout(15000);
            conn.setRequestMethod("GET");
            conn.setDoInput(true);
            conn.connect();
            conn.getResponseCode();

            is = conn.getInputStream();

            Reader reader = null;
            reader = new InputStreamReader(is);
            char[] buffer = new char[2048];
            reader.read(buffer);
            return new String(buffer);
        } finally {
            if (is != null) {
                is.close();
            }
        }
    }

    @Override
    protected void onPostExecute(List<String> result) {
        super.onPostExecute(result);

    }

    public interface ConsultaConcluidaLoginListener {
        void onConsultaConcluida(List<String> result);
    }
}

如果您需要更多详细信息，请询问。

Answer 1

将进度条添加到您的布局（不确定），并在您初始化异步任务时打开可见性。在异步的回调中，关闭可见性。

根据要求：

login = txtUsuario.getText().toString();
senha = txtSenha.getText().toString();
yourProgressBar.setVisibility(View.VISIBLE);
ConsultaLogin.URL_STRING = "http://186.207.85.205:7001/com.henrique.rest/api/v1/status/login?usu_login=" + login + "&usu_senha=" + senha;
new ConsultaLogin(this).execute();

结果：

@Override
public void onConsultaConcluida(List<String> result) {
    if (result.isEmpty()) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Erro");
        builder.setMessage("Usuario ou Senha Incorreto!");
        builder.setNeutralButton("Ok", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                login = "";
                senha = "";
                txtSenha.getText().clear();
                txtUsuario.requestFocus();
            }
        });
        alerta = builder.create();
        alerta.show();
    } else {
        yourProgressBar.setVisibility(View.GONE);
        Intent intent = new Intent(this, MainActivity.class);
        startActivity(intent);
    }
}

执行 ASyncTask 时加载 ProgressBar

Load ProgressBar while executing ASyncTask

android

android-asynctask

progress-bar