如何在Android应用程序的WebView的操作栏按钮中添加返回和主页按钮？

Question

I made an app which uses WebView to display a mobile website. I have also added ProgressDialog which appears till the page finishes loading. I would like to add a back & home button in the action bar of my app. These buttons should appear when any link is clicked in the home page of the mobile website & disappear when we return to the home page (Similar to Indeed Job search App).

Answer 1

This page may help you.

Action bar buttons behaves just like the elements of the overflow menu.
Just add one <item> inside your menu resource file with the attribute app:showAsAction="ifRoom" or app:showAsAction="always" .

According to android dev site your xml should look like this:

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <!-- "Mark Favorite", should appear as action button if possible -->
    <item
        android:id="@+id/action_back"
        android:icon="@drawable/ic_go_back"
        android:title="@string/action_back"
        app:showAsAction="ifRoom"/>

    <!-- Settings, should always be in the overflow -->
    <item android:id="@+id/action_settings"
          android:title="@string/action_settings"
          app:showAsAction="never"/>

</menu>

Then you have to attach a listener for that button: just handle as if it was in the overflow menu. So you have to override onOptionsItemSelected adding something like if (mWebView.canGoBack()) {mWebView.goBack();}

Here's the code:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.action_back:
            if (mWebView.canGoBack()) {
                mWebView.goBack();
            }

        // ... other cases ...

    }
}

Answer 2

您可以简单地设置这两个菜单操作的可见性，具体取决于URL更改时的当前URL：

actionBack.setVisibility(yourWebView.getUrl().equals("www.yourHomePage.com") ? View.INVISIBLE : View.VISIBLE);