ProgressBar

<ProgressBar
        android:id="@+id/progressbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        style="@android:style/Widget.ProgressBar.Horizontal"
        />

 //进度条的类ProgressBar
        final ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressbar);
        //设置进度条的最大值100
        progressBar.setMax(100);

        //新线程不要忘记调用start方法
        new Thread(new Runnable() {
            @Override
            public void run() {
                for(int i = 0; i < 100; i++) {
                    try {
                        //让线程休眠500ms(半秒钟）
                        Thread.sleep(500);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    //给进度条设置进度
                    progressBar.setProgress(i);
                }
            }
        }).start();