【AsyncTask】简单使用

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MyAsyncTaskDemo extends Activity {

    private ProgressBar bar = null;
    private TextView info = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.main);

        this.bar = (ProgressBar) super.findViewById(R.id.bar);
        this.info = (TextView) super.findViewById(R.id.info);
        ChildUpdate child = new ChildUpdate() ;
        child.execute(100) ;
    }

    // 每次处理后台进度的类型是Integer、更新之后的数值Integer，最后的结果返回的是字符串
    private class ChildUpdate extends AsyncTask<Integer, Integer, String> {
        @Override
        protected void onPostExecute(String result) {
            MyAsyncTaskDemo.this.info.setText(result) ;
        }
        @Override  // 每次更新之后的内容
        protected void onProgressUpdate(Integer... values) {    
            MyAsyncTaskDemo.this.info.setText("当前的进度值是：" + String.valueOf(values[0])) ;
        }
        @Override  // 每次的进度处理，可以更新UI组件
        protected String doInBackground(Integer... params) { 
            for (int x = 0; x < 100; x++) {
                MyAsyncTaskDemo.this.bar.setProgress(x); // 设置进度
                // 更新，调用更新操作
                this.publishProgress(x) ;    
                try {// 延迟的操作由外部决定
                    Thread.sleep(params[0]);
                } catch (InterruptedException e) {
                }
            }
            return "执行完毕";
        }

    }
}