如果在 WebView 中按下后退按钮，如何返回上一页? [英] How to go back to previous page if back button is pressed in WebView?

问题描述

我有一个应用程序，其中有一个 WebView 用于显示一些网站.它有效，单击网页中的链接会转到我的应用程序内网站的下一页.但是当我点击手机的后退按钮时，它会直接带我进入我的应用程序.我想返回到网站的上一页.我该怎么做?

I have an app in which I have a WebView where I display some websites. It works, clicking a link in the webpage goes to the next page in the website inside my app. But when I click the phone's back button, it takes me straight into my app. I want to go back to the previous page in the website instead. How can I do this?

这是我正在使用的代码示例:

Here is the code sample I'm using:

public class Webdisplay extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
        setContentView(R.layout.webdisplay);

        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
                Window.PROGRESS_VISIBILITY_ON); 

        Toast loadingmess = Toast.makeText(this,
                "Cargando El Diario de Hoy", Toast.LENGTH_SHORT);
        loadingmess.show();

        WebView myWebView;

        myWebView = (WebView) findViewById(R.id.webview);
        myWebView.getSettings().setJavaScriptEnabled(true);
        myWebView.loadUrl("http://www.elsalvador.com");
        myWebView.setWebViewClient(new WebViewClient());
        myWebView.setInitialScale(1);
        myWebView.getSettings().setBuiltInZoomControls(true);
        myWebView.getSettings().setUseWideViewPort(true);

        final Activity MyActivity = this;
        myWebView.setWebChromeClient(new WebChromeClient() 
        {
            public void onProgressChanged(WebView view, int progress)   
            {
                MyActivity.setTitle("Loading...");
                MyActivity.setProgress(progress * 100); 

                if(progress == 100)
                    MyActivity.setTitle(R.string.app_name);
            }
        });
    }
}

推荐答案

我在我的 WebViews 活动中使用了这样的东西:

I use something like this in my activities with WebViews:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (event.getAction() == KeyEvent.ACTION_DOWN) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_BACK:
                if (mWebView.canGoBack()) {
                    mWebView.goBack();
                } else {
                    finish();
                }
                return true;
        }

    }
    return super.onKeyDown(keyCode, event);
}

要使此代码起作用，您需要向包含 WebView 的 Activity 添加一个字段:

For this code to work, you need to add a field to the Activity containing the WebView:

private WebView mWebView;

在 onCreate() 方法中初始化它，你应该很高兴.

Initialize it in the onCreate() method and you should be good to go.

mWebView = (WebView) findViewById(R.id.webView);

这篇关于如果在 WebView 中按下后退按钮，如何返回上一页?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！