进度条对话框

public class MainActivity extends Activity {
    private ProgressDialog dialog;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        //创建一个进度条对话框对象
        dialog = new ProgressDialog(MainActivity.this);
        // dialog.setCancelable(false);//是否可以取消
        dialog.setIcon(R.drawable.ic_launcher);
        // dialog.cancel();//取消对话框
        dialog.setTitle("正在下载");
        dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);// 设置样式
        dialog.setMax(100);
        dialog.setProgress(50);
        dialog.setOnCancelListener(new OnCancelListener() {
            public void onCancel(DialogInterface dialog) {
                Toast.makeText(MainActivity.this, "残忍的取消下载", 0).show();
            }
        });
        return true;
    }

    public boolean onOptionsItemSelected(MenuItem item) {
        dialog.show();
        new Thread(){
            public void run() {
                for (int i = 0; i <= 100; i++) {
                    try {
                        Thread.sleep(100);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    //dialog.setProgress(i);
                //每次加1
                dialog.incrementProgressBy(1);
                }

                for (int j = 100; j >= 0; j--) {
                    try {
                        Thread.sleep(100);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    //dialog.setProgress(j);
                //每次减1  
                dialog.incrementProgressBy(-1);
                }

            };
        }.start();

        return super.onOptionsItemSelected(item);
    }

}