如何设置ScrollView的起始位置？

Question

我一直试图设置滚动视图的初始位置,但没有找到方法.有没有人有任何想法？此外,我还有一个GoogleMaps片段作为滚动视图的子项.

谢谢,

瑞安

Answer 1

是的,这是可能的:

ScrollView.scrollTo(int x, int y);
ScrollView.smoothScrollTo(int x, int y);
ScrollView.smoothScrollBy(int x, int y);

可以用于此.x和y参数是在水平和垂直轴上滚动到的坐标.

代码示例:

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

        ScrollView sv = (ScrollView) findViewById(R.id.scrollView);
        sv.scrollTo(0, 100);
     }

在该示例中,一旦Activity启动,您ScrollView将向下滚动100像素.

您还可以尝试延迟滚动过程:

final ScrollView sv = (ScrollView) findViewById(R.id.scrollView);

Handler h = new Handler();

h.postDelayed(new Runnable() {

    @Override
    public void run() {
        sv.scrollTo(0, 100);            
    }
}, 250); // 250 ms delay

Answer 2

The accepted answer is not working for me. There is no direct way to set the initial position of a scroll view.

However, you can set the initial position before drawing the scroll view, like this:

rootView.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
    @Override
    public boolean onPreDraw() {
        scrollView.getViewTreeObserver().removeOnPreDrawListener(this);
        scrollView.setScrollY(100);
        return false;
    }
});

You can also use scrollView.setScrollY(100) inside Handler, but that will be jerky while scrolling.