AsyncTask异步任务

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private ProgressDialog mDialog;
    private TextView textView;

    @SuppressLint("StaticFieldLeak")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = (TextView) findViewById(R.id.tv);

        mDialog = new ProgressDialog(this);
        mDialog.setMax(100);
        mDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        mDialog.setCancelable(true);
        mDialog.setMessage("正在加载");

        new AsyncTask<Void, Integer, Void>() {
            @Override
            protected void onPreExecute() {
                super.onPreExecute();
                textView.setText("数据开始加载...");
                mDialog.show();
            }

            @Override
            protected Void doInBackground(Void... params) {
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        textView.setText("数据正在加载中...");
                    }
                });
                for (int i = 0; i <= 100; i++) {
                    SystemClock.sleep(50);
                    publishProgress(i);
                }
                return null;
            }

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

            @Override
            protected void onPostExecute(Void aVoid) {
                mDialog.dismiss();
                textView.setText("数据加载完毕");
                super.onPostExecute(aVoid);
            }
        }.execute();
    }
}