Question

如何判断一个控件滑动到顶部和底部android

Answer 1

方法/步骤

我们需要重写webview的滑动方法，自定义一个webview： FoundWebView（可自由命名）代码如下
package com.paoyx.widget;
import android.content.Context;
import android.util.AttributeSet;
import android.webkit.WebView;
/** * 重新webview
* @author paoyx */
public class FoundWebView extends WebView {
ScrollInterface web;
public FoundWebView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
public FoundWebView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public FoundWebView(Context context, AttributeSet attrs) {

super(context, attrs);
// TODO Auto-generated constructor stub
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
//Log.e("hhah",""+l+" "+t+" "+oldl+" "+oldt);
web.onSChanged(l, t, oldl, oldt);
}
public void setOnCustomScroolChangeListener(ScrollInterface t){ this.web=t;
}
/**
* 定义滑动接口
* @param t
*/
public interface ScrollInterface {

public void onSChanged(int l, int t, int oldl, int oldt) ;
}}
在activity的onCreate方法中调用该webview，代码如下：
private FoundWebView mWebView;
mWebView = (FoundWebView)findViewById(R.id.mWebView);
mWebView.setOnCustomScroolChangeListener(new ScrollInterface() {
@Override
public void onSChanged(int l, int t, int oldl, int oldt) {

// TODO Auto-generated method stub
float webcontent = mWebView.getContentHeight()*mWebView.getScale();//webview的高度

float webnow = mWebView.getHeight()+ mWebView.getScrollY();//当前webview的高度
if( mWebView.getContentHeight()* mWebView.getScale() -( mWebView.getHeight()+ mWebView.getScrollY())==0){

//已经处于底端
lay_bottom_layout.setVisibility(View.VISIBLE);

}else {

lay_bottom_layout.setVisibility(View.GONE);
}
//已经处于顶端
if (mWebView.getScaleY() == 0) {
}
}});

Answer 2

用这个方法，android控件自带的： isFocusable()；