如何在滚动视图中获取滚动到顶部和底部的确切事件

Question

我尝试了很多在此处解释的方法 Whosebug.But 我仍然无法完美地获取滚动视图中的每个事件。

我打算做的是在到达顶部或底部时更改 edittext 中的文本（包装在滚动视图中），以便可以加载大文件。

        public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
            View view = (View) scrollView.getChildAt(scrollView.getChildCount() - 1);
            int diff = (view.getBottom() - (scrollView.getHeight() + scrollView.getScrollY()));

            // if diff is zero, then the bottom has been reached
            if (diff == 0) {
                if(index<texts.size()-1){
                    scrollView.scrollTo(0,0);
                    index++;
                    mInput.setText(texts.get(index));
                }
            }
                // do stuff similarly for top position reached
        }

Answer 1

尝试这样的事情：

 @Override
 protected void onScrollChanged(int l, int t, int oldl, int oldt) { 

 if(view.getTop()==t){
    // reaches the top end
    }

 View view = (View) getChildAt(getChildCount()-1); 
 int diff = (view.getBottom()-(getHeight()+getScrollY()+view.getTop()));// Calculate the scrolldiff 
 if( diff <= 0 ){ 
    // if diff is zero, then the bottom has been reached
     Log.d(ScrollTest.LOG_TAG, "MyScrollView: Bottom has been reached" );
         }
super.onScrollChanged(l, t, oldl, oldt); 
    }

希望对您有所帮助。

如何在滚动视图中获取滚动到顶部和底部的确切事件

How to get exact events of scrolled to top and bottom in scrollview

android

scrollview