我有一个web视图，显示一个HTML文件。当用户滚动到的WebView该文件的底部，我想有一个按钮，这是previously隐藏展现出来，用户就可以preSS做一些活动而

I have a webview which shows an html file. When the user scrolls to the bottom of this file in webview, I want a button that was previously hidden to show up, which the user can then press to do some activity

我做的iOS，在这里我只设置委托到ViewController，只是设置按钮，可见类似的东西。我该怎么做在Android上类似的事情？我注意到没有像iOS中的回调方法。

I did something similar in iOS, where I just set the delegate to the ViewController and just set the button as visible. How do I do something similar on Android? I noticed there isn't a callback method like in iOS.

编辑：现在，我有一个活动有两个对象：包含我的文字一个web视图和一个按钮，这是目前可见的。我希望我的活动，收到消息时的WebView文本滚动至底部，并可见按钮

Right now, I have an activity with 2 objects: a webview containing my text, and a button which is currently invisible. I want my activity to receive a message when the webview text scrolls to the bottom, and make the button visible

推荐答案

加载/可见光按钮仅在web视图达/滚动至底部。

Loading / Visible button only when webview reached / scrolled to bottom.

创建JavaScript类：

Create JavaScript class :

public class JavaScriptInterface {

  @android.webkit.JavascriptInterface
  public void didScrollToBottom() {
    Log.d(TAG, "Scroll to Bottom");
    myHandler.post(new Runnable() {
      @Override
      public void run() {
         btnAccept.setVisibility(View.VISIBLE);

          }
       });
      }
    }

在的onCreate（）：

In onCreate() :

final JavaScriptInterface jsInterface = new JavaScriptInterface();
myWebView.addJavascriptInterface(jsInterface, "AndroidFunction");