Android webview 页面不可用

Question

我开发了一个小型 android webview 应用程序来访问内部(本地网络)基于 PHP 的站点。

这是我的代码:

package com.CheckInventory;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.WindowManager;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebStorage;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

@SuppressWarnings("unused")
public class CheckInventoryActivity extends Activity {
    WebView webview;
    String username; 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        setContentView(R.layout.main);
        webview = (WebView) findViewById(R.id.webview);
        WebView webView = (WebView) findViewById(R.id.webview);
        webView.setBackgroundColor(0);
        webView.setBackgroundResource(R.drawable.myimage);
        webView.addJavascriptInterface(new JavaScriptInterface(this), "Android");
        WebSettings webSettings = webview.getSettings();
        webSettings.setLoadWithOverviewMode(true);

        webview.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);

        webSettings.setJavaScriptEnabled(true);
        webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
        webSettings.setDatabasePath("/data/data/"+this.getPackageName()+"/databases/");
        webSettings.setDomStorageEnabled(true);
        webview.setWebChromeClient(new WebChromeClient());
        webview.loadUrl("http://192.168.0.124/android");
        webview.setWebViewClient(new HelloWebViewClient());

    }
    private class HelloWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    }


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

}

该网站有身份验证，但我想在应用程序和网站之间添加一些身份验证(我该怎么做？可能在调用 url 时传递参数)，其次，更重要的是，我具体放在哪里onReceivedError，因此如果用户离开建筑物或连接松动，他们永远不会看到 url 或页面。

public void onReceivedError(WebView view, int errorCod,String description, String failingUrl) {
        Toast.makeText(Webform.this, "Your Internet Connection May not be active Or " + description , Toast.LENGTH_LONG).show();
    }

我在Detecting Webview Error and Show Message中看到了这个解释但我不知道在哪里实现。

提前致谢

Answer 1

您需要创建扩展 WebViewClient 并实现方法 OnReceivedError

的类

像这样

class myWebClient extends WebViewClient {

    @Override
    public void onReceivedError(WebView view, int errorCode,
            String description, String failingUrl) {
        Toast.makeText(Webform.this, "Your Internet Connection May not be active Or " + description , Toast.LENGTH_LONG).show();
        super.onReceivedError(view, errorCode, description, failingUrl);
    }

}

然后您需要为您的 WebView 设置新的 WebViewClient

    web = (WebView) findViewById(R.id.webview);
    web.setWebViewClient(new myWebClient());

希望对你有帮助