Android开发笔记（四十九）异步任务处理AsyncTask

        style="?android:attr/progressBarStyleHorizontal"

public static ProgressDialog show(Context context, CharSequence title, CharSequence message)

import android.os.AsyncTask;

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

	private final static String TAG = "ProgressBarTask";
	private ProgressListener mListener;

	public ProgressAsyncTask() {
		super();
	}
	
	public void setProgressListener(ProgressListener listener) {
		mListener = listener;
	}
	
	public ProgressListener getProgressListener() {
		return mListener;
	}
	
	@Override
	protected String doInBackground(String... params) {
		int ratio = 0;
		for (; ratio<=100; ratio+=5) {
			//睡眠200毫秒模拟网络通信处理
			try {
				Thread.sleep(200);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			publishProgress(ratio);
//			if (ratio >= 50) {
//				cancel(false);
//			}
		}
		return params[0];
	}

	@Override
	protected void onPreExecute() {
		mListener.onBegin();
	}

	@Override
	protected void onProgressUpdate(Integer... values) {
		mListener.onUpdate(values[0], 0);
	}

	@Override
	protected void onPostExecute(String result) {
		mListener.onFinish(result);
	}

	@Override
	protected void onCancelled(String result) {
		mListener.onCancel(result);
	}
	
}

import com.example.exmthread.task.ProgressAsyncTask;
import com.example.exmthread.task.ProgressListener;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

public class AsyncTaskActivity extends Activity implements OnClickListener, ProgressListener {

	private TextView tv_async;
	private ProgressBar pb_async;
	private ProgressDialog m_pd;
	
	public int mShowMode;
	public int BAR_CIRCLE = 0;
	public int BAR_HORIZONTAL = 1;
	public int DIALOG_CIRCLE = 10;
	public int DIALOG_HORIZONTAL = 11;

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

		Button btn_bar = (Button) findViewById(R.id.btn_bar);
		Button btn_dialog_circle = (Button) findViewById(R.id.btn_dialog_circle);
		Button btn_dialog_hrz = (Button) findViewById(R.id.btn_dialog_hrz);
		btn_bar.setOnClickListener(this);
		btn_dialog_circle.setOnClickListener(this);
		btn_dialog_hrz.setOnClickListener(this);
		
		tv_async = (TextView) findViewById(R.id.tv_async);
		pb_async = (ProgressBar) findViewById(R.id.pb_async);
	}

	@Override
	public void onClick(View v) {
		if (v.getId() == R.id.btn_bar) {
			startTask(BAR_HORIZONTAL, "三国演义");
		} else if (v.getId() == R.id.btn_dialog_circle) {
			startTask(DIALOG_CIRCLE, "西游记");
		} else if (v.getId() == R.id.btn_dialog_hrz) {
			startTask(DIALOG_HORIZONTAL, "红楼梦");
		}
	}
	
	private void startTask(int mode, String msg) {
		mShowMode = mode;
		ProgressAsyncTask asyncTask = new ProgressAsyncTask();
		asyncTask.setProgressListener(this);
		asyncTask.execute(msg);
	}
	
	private void closeDialog() {
		if (m_pd != null && m_pd.isShowing() == true) {
			m_pd.dismiss();
		}
	}

	@Override
	public void onFinish(String result) {
		String desc = String.format("您要阅读的《%s》已经加载完毕", result);
		tv_async.setText(desc);
		closeDialog();
	}

	@Override
	public void onCancel(String result) {
		String desc = String.format("您要阅读的《%s》已经取消加载", result);
		tv_async.setText(desc);
		closeDialog();
	}

	@Override
	public void onUpdate(int progress, int sub_progress) {
		tv_async.setText("当前加载进度为" + progress + "%");
		if (mShowMode == BAR_HORIZONTAL) {
			pb_async.setProgress(progress);
			pb_async.setSecondaryProgress(sub_progress);
		} else if (mShowMode == DIALOG_HORIZONTAL) {
			m_pd.setProgress(progress);
			m_pd.setSecondaryProgress(sub_progress);
		}
	}

	@Override
	public void onBegin() {
		tv_async.setText("开始加载");
		if (m_pd == null || m_pd.isShowing() != true) {
			if (mShowMode == DIALOG_CIRCLE) {
				m_pd = ProgressDialog.show(this, "稍等", "页面加载中……");
			} else if (mShowMode == DIALOG_HORIZONTAL) {
				m_pd = new ProgressDialog(this);
				m_pd.setTitle("稍等");
				m_pd.setMessage("页面加载中……");
				m_pd.setIcon(R.drawable.ic_search);
				m_pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
				m_pd.show();
			}
		}
	}

}