java - Android Webview 回退

Question

我一直在尝试编译一个 Android 应用程序，但我收到错误提示

java: non-static method canGoBack() cannot be referenced from a static context
java: non-static method goBack() cannot be referenced from a static context

所以基本上我试图将 airpush 集成到这个应用程序中，但我正在使用 goback() 函数...我希望它执行 airpush.startLandingPageAd(); 退出应用程序时(当没有更多历史记录时......

package bizkit.app1;

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.view.KeyEvent;
import com.djtjetyj.dghwdgh54656.Airpush;

public class FengShuiTips extends Activity {
    private Airpush airpush;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        WebView webView = (WebView)findViewById(R.id.webView);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebChromeClient(new WebChromeClient());
        webView.loadUrl("https://www.google.com");
        Airpush airpush=new Airpush(getApplicationContext(), null);
        airpush.startPushNotification(false);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && WebView.canGoBack()) {
            WebView.goBack();
            return true;
        }
        airpush.startLandingPageAd();
        return super.onKeyDown(keyCode, event);
    }
}

Answer 1

你应该添加字段

private WebView mWebView

并将 onCreate 更改为:

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mWebView = (WebView)findViewById(R.id.webView);
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.setWebChromeClient(new WebChromeClient());
        mWebView.loadUrl("https://www.google.com");
        Airpush airpush=new Airpush(getApplicationContext(), null);
        airpush.startPushNotification(false);
    }

所以在函数中:

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()) {
            mWebView.goBack();
            return true;
        }
        airpush.startLandingPageAd();
        return super.onKeyDown(keyCode, event);
    }

它现在应该可以工作了。