ProgressBar的使用

<ProgressBar
android:layout_width="40dp"
android:layout_height="40dp"
android:id="@+id/pb"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="小明"
android:background="#999"
android:onClick="click"
/>

private ProgressBar pb;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pb = (ProgressBar) findViewById(R.id.pb);
pb.setVisibility(View.VISIBLE);
}
public void click(View view){
if(pb.getVisibility()==8){//显示为0，不显示为8
pb.setVisibility(View.VISIBLE);
}else if(pb.getVisibility()==0)
{
pb.setVisibility(View.GONE);
}
}