AsyncTask的使用

简单的AnsyTask的使用demo

1.定义一个模拟网络操作的类

package com.example.administrator.myapplication;

/**
 * Created by Administrator on 2016/7/11.
 * 模拟网络环境
 */
public class NetOperator {

    public void operation(){
        try {
            //睡眠一秒
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

}

2.定义AsnyTask的类

package com.example.administrator.myapplication;

import android.os.AsyncTask;
import android.util.Log;
import android.widget.ProgressBar;
import android.widget.TextView;

/**
 * Created by Administrator on 2016/7/11.
 * * 生成该类的对象，并调用execute方法之后
 * 首先执行的是onProExecute方法
 * 其次执行doInBackgroup方法
 */
public class ProgressBarAsyncTask extends AsyncTask {
    private TextView textView;
    private ProgressBar progressBar;

    ProgressBarAsyncTask(TextView textView, ProgressBar progressBar) {
        super();
        this.textView = textView;
        this.progressBar = progressBar;

    }

    @Override
    //被后台线程执行后，被UI线程被调用，一般用于初始化界面控件，如进度条
    protected void onPreExecute() {
        super.onPreExecute();
        Log.d("TEST","初始化操作");
    }

    @Override
    //在PreExcute执行后被启动AysncTask的后台线程调用，将结果返回给UI线程
    protected Object doInBackground(Object[] objects) {
        //这个方法执行多线程操作
        NetOperator netOperator = new NetOperator();
        int i = 0;
        for (i = 10; i <= 100; i += 10) {
            netOperator.operation();
            publishProgress(i);
        }
        Log.d("TEST","后台执行多线程");
         return i + objects.toString();
    }

    @Override
    //执行完后由UI线程调用，用于更新界面操作
    protected void onPostExecute(Object o) {
        textView.setText("异步执行操作结束！");
        Log.d("TEST","多线程执行结束");
    }

    @Override
    //更新进度条
    protected void onProgressUpdate(Object[] values) {
        int value= (int) values[0];
        progressBar.setProgress(value);
        Log.d("TEST","更新进度条");

    }
}

3.在Activity中使用

package com.example.administrator.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private TextView myTextView;
    private ProgressBar myProcessBar;
    private Button myButton;

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

        initView();
    }

    private void initView() {
        myTextView = (TextView) findViewById(R.id.textView);
        myProcessBar = (ProgressBar) findViewById(R.id.progressBar);
        myButton = (Button) findViewById(R.id.button);

        myButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ProgressBarAsyncTask progressBarAsyncTask=new ProgressBarAsyncTask(myTextView,myProcessBar);
                progressBarAsyncTask.execute(1000);
            }
        });
    }
}