Asyncask 클래스

AsyncTask 클래스

작업 스레드와 관련된 복잡한 부분을 쉽게 처리해주는 클래스(API15 버전부터 추가)

Handler 클래스나 Progress Dialog 대신 AsyncTask 클래스를 이용하면 한번에 처리 가능

AsyncTask

1. 레이아웃

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.progdv.asynctask.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/btnTask"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="데이터베이스 엑세스"/>

    </LinearLayout>
</RelativeLayout>

2. 메인 액티비티

package com.progdv.asynctask;

import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    Button btnTask;
    ProgressDialog dialog;
    int pValue;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnTask = (Button)findViewById(R.id.btnTask);
        btnTask.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new MyAsyncTask().execute(100);
            }
        });
    }

    public class MyAsyncTask extends AsyncTask<Integer, Integer, String>{

        @Override
        protected void onPreExecute() { // 가장 처음에 호출되는 메서드
            super.onPreExecute();
            dialog = new ProgressDialog(MainActivity.this);
            dialog.setTitle("처리중...");
            dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            dialog.setButton(ProgressDialog.BUTTON_NEGATIVE, "취소",
                    new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    });
            dialog.show();
        }

        @Override
        protected String doInBackground(Integer... params) {
            while(pValue < params[0]){
                pValue++;
                publishProgress(pValue);
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            pValue = 0;
            return "다운로드 완료";
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            super.onProgressUpdate(values);
            dialog.setProgress(values[0]);
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);

            dialog.dismiss();
            Toast.makeText(getApplicationContext(), s, Toast.LENGTH_SHORT).show();
        }
    }
}

데이터베이스 액세스 버튼을 누르면 게이지가 올라간 뒤 끝나면 종료된다.