Android Webview js 简单应用

Android 的 Webview 在低版本和高版本采用了不同的webkit版本内核，4.4后直接使用了Chrome。

简单的加载 WebView 界面：
· 带有Http请求头的

loadUrl(String url,Mapadditional HttpHeaders)

· 不带Http请求头的

loadUrl(String url)

· 常用属性：

· clearHistory()：清除当前webview访问的历史记录。· reload()：重新reload当前的URL，即刷新。常见用法：Back键控制网页后退问题：在不做任何处理前提下 ，浏览网页时点击系统的“Back”键,整个 Browser 会调用 finish()而结束自身  目标：点击返回后，是网页回退而不是推出浏览器· getScrollY()：该方法返回的当前可见区域的顶端距整个页面顶端的距离，也就是当前内容滚动的距离。· getHeight()：方法都返回当前WebView这个容器的高度。其实以上两个方法都属于View。· getContentHeight()：该方法返回整个HTML页面的高度，但该高度值并不等同于当前整个页面的高度，因为WebView有缩放功能， 所以当前整个页面的高度实际上应该是原始HTML的高度再乘上缩放比例。因此，准确的判断方法应该是if (webView.getContentHeight() * webView.getScale() == (webView.getHeight() + webView.getScrollY())) {//已经处于底端}if(webView.getScrollY() == 0){//处于顶端}pageUp(boolean top)：将WebView展示的页面滑动至顶部。pageDown(boolean bottom)：将WebView展示的页面滑动至底部。

解决方案：在当前Activity中处理并消费掉该 Back 事件

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

· 清除网页缓存和 Cookie

 CookieSyncManager cookieSyncManager = CookieSyncManager.createInstance(getApplicationContext());        CookieManager cookieManager = CookieManager.getInstance();        cookieManager.setAcceptCookie(true);        cookieManager.removeSessionCookie();        cookieManager.removeAllCookie();        cookieSyncManager.sync();

WebSettings
作用：对 WebView 进行的管理

WebSettings webSettings = webView.getSettings();

· 属性

WebSettings webSettings = webView.getSettings();//如果访问的页面中要与Javascript交互，则webview必须设置支持JavascriptwebSettings.setJavaScriptEnabled(true);// 若加载的 html 里有JS 在执行动画等操作，会造成资源浪费（CPU、电量）// 在 onStop 和 onResume 里分别把 setJavaScriptEnabled() 给设置成 false 和 true 即可webSettings.setPluginsEnabled(true);//设置自适应屏幕，两者合用webSettings.setUseWideViewPort(true); //将图片调整到适合webview的大小webSettings.setLoadWithOverviewMode(true); // 缩放至屏幕的大小//缩放操作webSettings.setSupportZoom(true); //支持缩放，默认为true。是下面那个的前提。webSettings.setBuiltInZoomControls(true); //设置内置的缩放控件。若为false，则该WebView不可缩放webSettings.setDisplayZoomControls(false); //隐藏原生的缩放控件//其他细节操作webSettings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK); //关闭webview中缓存webSettings.setAllowFileAccess(true); //设置可以访问文件webSettings.setJavaScriptCanOpenWindowsAutomatically(true); //支持通过JS打开新窗口webSettings.setLoadsImagesAutomatically(true); //支持自动加载图片webSettings.setDefaultTextEncodingName("utf-8");//设置编码格式

· 获取WebView的标题

 WebChromeClient wvcc = new WebChromeClient() {                @Override                public void onReceivedTitle(WebView view, String title) {                    super.onReceivedTitle(view, title);                    setTitle(title);                }            };            webView.setWebChromeClient(wvcc);

· 防止 webview 跳转到系统浏览器

 webView.setWebViewClient(new WebViewClient() {                @Override                public boolean shouldOverrideUrlLoading(WebView view,                 String url) {   //返回值是true的时候控制去WebView打开，为false调用系统浏览器或第三方浏览器                    view.loadUrl(url);                    return true;                }            });

· 当 webview 加载完成之后

   webview.setWebViewClient(new WebViewClient() {                @Override                public void onPageFinished(WebView view, String url) {                    super.onPageFinished(view, url);                    //自定义操作                }            });

· 开启Js

webview.addJavascriptInterface(newgetPayJson());  //方法名 (和后台沟通写一致的)

· 如果对 js 的返回的东西进行修改那么：

onJsAlert： 修改js弹框 （由网页的弹窗修改为原生和自定义的dialog）onJsConfirm：处理confirm弹出框onJsPrompt：处理prompt弹出框

详细代码：

  @Override                public boolean onJsAlert(WebView view, String url, String message, JsResult result) {                    final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());                    builder.setTitle("提示").setMessage(message).setPositiveButton("确定", null);                    // 不需要绑定按键事件                    // 屏蔽keycode等于84之类的按键                    builder.setOnKeyListener(new OnKeyListener() {                        public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {                            Log.v("onJsAlert", "keyCode==" + keyCode + "event=" + event);                            return true;                        }                    });                    // 禁止响应按back键的事件                    builder.setCancelable(false);                    AlertDialog dialog = builder.create();                    dialog.show();                    result.confirm();// 因为没有绑定事件，需要强行confirm,否则页面会变黑显示不了内容。                    return true;                }                @Override                public boolean onJsConfirm(WebView view, String url, String message, final JsResult result) {                    final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());                    builder.setTitle("提示").setMessage(message).setPositiveButton("确定", new DialogInterface.OnClickListener() {                        public void onClick(DialogInterface dialog, int which) {                            result.confirm();                        }                    }).setNeutralButton("取消", new DialogInterface.OnClickListener() {                        public void onClick(DialogInterface dialog, int which) {                            result.cancel();                        }                    });                    builder.setOnCancelListener(new DialogInterface.OnCancelListener() {                        @Override                        public void onCancel(DialogInterface dialog) {                            result.cancel();                        }                    });                    // 屏蔽keycode等于84之类的按键，避免按键后导致提示消息而页面无法再弹出提示的问题                    builder.setOnKeyListener(new OnKeyListener() {                        @Override                        public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {                            Log.v("onJsConfirm", "keyCode==" + keyCode + "event=" + event);                            return true;                        }                    });                    // 禁止响应按back键的事件                    // builder.setCancelable(false);                    AlertDialog dialog = builder.create();                    dialog.show();                    return true;                }                @Override                public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, final JsPromptResult result) {                    final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());                    builder.setTitle("提示").setMessage(message);                    final EditText et = new EditText(view.getContext());                    et.setSingleLine();                    et.setText(defaultValue);                    builder.setView(et).setPositiveButton("确定", new DialogInterface.OnClickListener() {                        public void onClick(DialogInterface dialog, int which) {                            result.confirm(et.getText().toString());                        }                    })                            .setNeutralButton("取消", new DialogInterface.OnClickListener() {                                public void onClick(DialogInterface dialog, int which) {                                    result.cancel();                                }                            });                    // 屏蔽keycode等于84之类的按键，避免按键后导致提示消息而页面无法再弹出提示的问题                    builder.setOnKeyListener(new OnKeyListener() {                        public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {                            Log.v("onJsPrompt", "keyCode==" + keyCode + "event=" + event);                            return true;                        }                    });                    AlertDialog dialog = builder.create();                    dialog.show();                    return true;                }            };

最后贴上这个类的全部代码：带有微信支付宝银联支付

import android.annotation.SuppressLint;import android.content.DialogInterface;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.text.TextUtils;import android.util.Log;import android.view.KeyEvent;import android.webkit.JavascriptInterface;import android.webkit.JsPromptResult;import android.webkit.JsResult;import android.webkit.WebChromeClient;import android.webkit.WebSettings;import android.webkit.WebView;import android.webkit.WebViewClient;import android.app.AlertDialog;import com.alipay.sdk.app.PayTask;import com.orhanobut.logger.Logger;import com.tencent.mm.sdk.modelpay.PayReq;import com.unionpay.UPPayAssistEx;import com.unionpay.uppay.PayActivity;import android.content.DialogInterface.OnKeyListener;import android.widget.EditText;import org.json.JSONException;import org.json.JSONObject;import java.net.URLEncoder;import java.util.HashMap;import java.util.Map;import sdy.com.longjiangtravel.R;import sdy.com.longjiangtravel.app.MyApplication;import sdy.com.longjiangtravel.http.api.UrlApi;import sdy.com.longjiangtravel.http.json.JSONObjectEx;import sdy.com.longjiangtravel.pay.PayResult;import sdy.com.longjiangtravel.utils.AlertView.AlertView;import sdy.com.longjiangtravel.utils.AlertView.OnItemClickListener;import sdy.com.longjiangtravel.utils.AndroidDes3Util;import sdy.com.longjiangtravel.utils.GetToast;import static android.view.KeyEvent.KEYCODE_BACK;/** * Created by admin on 2017/5/2. */public class WebYunkanDetialActivity extends AppCompatActivity {    private WebView seckill_webview;    private Map<String, String> extraHeaders;    private static final int SDK_PAY_FLAG = 1;    private static final int SDK_AUTH_FLAG = 2;    private String head_title = "";    private String backurl;    public static OnR onR;    private static final String R_SUCCESS = "success";    private static final String R_FAIL = "fail";    private static final String R_CANCEL = "cancel";    @SuppressLint("HandlerLeak")    private Handler mHandler = new Handler() {        @SuppressWarnings("unused")        public void handleMessage(Message msg) {            switch (msg.what) {                case SDK_PAY_FLAG: {                    @SuppressWarnings("unchecked")                    PayResult payResult = new PayResult((Map<String, String>) msg.obj);                    String resultInfo = payResult.getResult();                    String resultStatus = payResult.getResultStatus();                    if (TextUtils.equals(resultStatus, "9000")) {                        new AlertView("提示", "支付成功", "确定", null, null, WebYunkanDetialActivity.this, AlertView.Style.Alert, new OnItemClickListener() {                            @Override                            public void onItemClick(Object o, int position) {                                if (position == -1) finish();                            }                        }).show();                        Intent intent = new Intent(getApplicationContext(), MyOrderActivity.class);                        Bundle bundle = new Bundle();                        bundle.putString("tab", "0");                        intent.putExtra("data", bundle);                        startActivity(intent);                    } else {                        new AlertView("提示", "取消支付", "确定", null, null, WebYunkanDetialActivity.this, AlertView.Style.Alert, null).show();                        Intent intent = new Intent(getApplicationContext(), MyOrderActivity.class);                        Bundle bundle = new Bundle();                        bundle.putString("tab", "0");                        intent.putExtra("data", bundle);                        startActivity(intent);                    }                    break;                }                case SDK_AUTH_FLAG: {                }                default:                    break;            }        }    };    public static final String LOG_TAG = "PayDemo";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_news);        seckill_webview = (WebView) findViewById(R.id.webview);        load();        onR = new OnR() {            @Override            public void onR() {                load();            }        };    }    private void initView() throws Exception {        seckill_webview.loadUrl(backurl, extraHeaders);        seckill_webview.addJavascriptInterface(new getPayJson(), "honorsoft");        seckill_webview.setWebViewClient(new WebViewClient() {            @Override            public boolean shouldOverrideUrlLoading(WebView view, String url) {                // TODO Auto-generated method stub                //返回值是true的时候控制去WebView打开，为false调用系统浏览器或第三方浏览器                view.loadUrl(url);                return true;            }        });    }    public boolean onKeyDown(int keyCode, KeyEvent event) {        if ((keyCode == KEYCODE_BACK)) {            if (head_title.equals("龙江游详情")) {                WebYunkanDetialActivity.this.finish();            } else if (head_title.equals("龙美收银台")) {                Intent intent = new Intent(WebYunkanDetialActivity.this, MyOrderActivity.class);                Bundle bundle = new Bundle();                bundle.putString("tab", "1");                intent.putExtra("data", bundle);                startActivity(intent);                WebYunkanDetialActivity.this.finish();            } else {                //重新刷机界面(如果没有加载出来数据)                load();            }            return true;        }        return super.onKeyDown(keyCode, event);    }    public class getPayJson {        @JavascriptInterface        public void getPayJson(String type, String json) throws JSONException {            Log.d("xzw", "++++++++++++++" + json);            Log.d("xzw", "+---------++++" + type);            if (type.equals("alipay")) {                payV2(json);            } else if (type.equals("wxpay")) {                JSONObject jsonObject = new JSONObject(json);                PayReq request = new PayReq();                request.appId = jsonObject.getString("appid");                request.partnerId = jsonObject.getString("partnerid");                request.prepayId = jsonObject.getString("prepayid");                request.packageValue = jsonObject.getString("package");                request.nonceStr = jsonObject.getString("noncestr");                request.timeStamp = jsonObject.getString("timestamp");                request.sign = jsonObject.getString("sign");                MyApplication.api.sendReq(request);                Intent intent = new Intent(getApplicationContext(), MyOrderActivity.class);                Bundle bundle = new Bundle();                bundle.putString("tab", "0");                intent.putExtra("data", bundle);                startActivity(intent);            } else if (type.equals("unionpay")) {                if (type.equals(null)) {                } else {                    JSONObjectEx jsonObject = new JSONObjectEx(json);                    String tn = jsonObject.getString("tn");                    String serverMode = "00";                    UPPayAssistEx.startPayByJAR(WebYunkanDetialActivity.this, PayActivity.class, null, null, tn, serverMode);                }            }        }        @JavascriptInterface        //添加购物车成功:        public void ljyCartSuccess() {            if (!MyApplication.P2PPreferences.getUid().equals("")) {                Log.d("添加购物车成功", "++++++++++=+++==++++");                Intent intent = new Intent(WebYunkanDetialActivity.this, ShoppingCarActivity.class);                startActivity(intent);            } else {                GetToast.useString(WebYunkanDetialActivity.this, "请先登录");                Intent intent = new Intent(WebYunkanDetialActivity.this, LoginActivity.class);                startActivity(intent);            }        }        @JavascriptInterface        public void ljyCartFail(String message) {//            GetToast.useString(WebYunkanDetialActivity.this, message);            if (!MyApplication.P2PPreferences.getUid().equals("")) {                Log.d("加入购物车失败", "-----------------------");                GetToast.useString(WebYunkanDetialActivity.this, message);            } else {                GetToast.useString(WebYunkanDetialActivity.this, "请先登录");                Intent intent = new Intent(WebYunkanDetialActivity.this, LoginActivity.class);                startActivity(intent);            }        }        @JavascriptInterface        public void dotel(String tel) {            // GetToast.useString(WebYunkanDetialActivity.this, tel);            Intent intent = new Intent();            intent.setAction(Intent.ACTION_DIAL);            Uri uri = Uri.parse("tel:" + tel);            intent.setData(uri);            startActivity(intent);        }        @JavascriptInterface        public void login() {            GetToast.useString(WebYunkanDetialActivity.this, "请先登录");            Intent intent = new Intent(WebYunkanDetialActivity.this, LoginActivity.class);            startActivity(intent);        }        //返回        @JavascriptInterface        public void ljyDetailBack() {            WebYunkanDetialActivity.this.finish();        }        //订单相关页面回退地址:        @JavascriptInterface        public void backUrl(String url) {            backurl = url;            Log.d("WebYunkanDetialActivity", "url======" + backurl);        }        //支付回退:        @JavascriptInterface        public void payGoBack() {            Log.d("WebYunkanDetialActivity", "======");            Intent intent = new Intent(WebYunkanDetialActivity.this, MyOrderActivity.class);            Bundle bundle = new Bundle();            bundle.putString("tab", "1");            intent.putExtra("data", bundle);            startActivity(intent);            WebYunkanDetialActivity.this.finish();        }    }    public void payV2(final String orderInfoJson) {        Runnable payRunnable = new Runnable() {            @Override            public void run() {                PayTask alipay = new PayTask(WebYunkanDetialActivity.this);                String orderInfo = orderInfoJson;                Map<String, String> result = alipay.payV2(orderInfo, true);                Log.i("msp", result.toString());                Message msg = new Message();                msg.what = SDK_PAY_FLAG;                msg.obj = result;                mHandler.sendMessage(msg);            }        };        Thread payThread = new Thread(payRunnable);        payThread.start();    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        if (data == null) {            return;        }        String str = data.getExtras().getString("pay_result");        if (str.equalsIgnoreCase(R_SUCCESS)) {            GetToast.useid(WebYunkanDetialActivity.this, R.string.pay_success);            Intent intent = new Intent(getApplicationContext(), MyOrderActivity.class);            Bundle bundle = new Bundle();            bundle.putString("tab", "0");            intent.putExtra("data", bundle);            startActivity(intent);        } else if (str.equalsIgnoreCase(R_FAIL)) {            GetToast.useid(WebYunkanDetialActivity.this, R.string.pay_fail);            Intent intent = new Intent(getApplicationContext(), MyOrderActivity.class);            Bundle bundle = new Bundle();            bundle.putString("tab", "0");            intent.putExtra("data", bundle);            startActivity(intent);        } else if (str.equalsIgnoreCase(R_CANCEL)) {            GetToast.useid(WebYunkanDetialActivity.this, R.string.pay_cancel);        }    }    public interface OnR {        public void onR();    }    private void load() {        try {            final String str = URLEncoder.encode(AndroidDes3Util.encode(MyApplication.P2PPreferences.getUid()), "UTF-8");            backurl = UrlApi.ip_js + "Order/ljyDetail?" + "row_id=" + getIntent().getStringExtra("scenicid") + "&user_id_crypt=" + str + "&mode=AES";            WebSettings setting = seckill_webview.getSettings();            setting.setJavaScriptEnabled(true);            WebChromeClient wvcc = new WebChromeClient() {                @Override                public void onReceivedTitle(WebView view, String title) {                    super.onReceivedTitle(view, title);                    head_title = title;                }                @Override                public boolean onJsAlert(WebView view, String url, String message, JsResult result) {                    final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());                    builder.setTitle("提示").setMessage(message).setPositiveButton("确定", null);                    // 不需要绑定按键事件                    // 屏蔽keycode等于84之类的按键                    builder.setOnKeyListener(new OnKeyListener() {                        public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {                            Log.v("onJsAlert", "keyCode==" + keyCode + "event=" + event);                            return true;                        }                    });                    // 禁止响应按back键的事件                    builder.setCancelable(false);                    AlertDialog dialog = builder.create();                    dialog.show();                    result.confirm();// 因为没有绑定事件，需要强行confirm,否则页面会变黑显示不了内容。                    return true;                }                @Override                public boolean onJsConfirm(WebView view, String url, String message, final JsResult result) {                    final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());                    builder.setTitle("提示").setMessage(message).setPositiveButton("确定", new DialogInterface.OnClickListener() {                        public void onClick(DialogInterface dialog, int which) {                            result.confirm();                        }                    }).setNeutralButton("取消", new DialogInterface.OnClickListener() {                        public void onClick(DialogInterface dialog, int which) {                            result.cancel();                        }                    });                    builder.setOnCancelListener(new DialogInterface.OnCancelListener() {                        @Override                        public void onCancel(DialogInterface dialog) {                            result.cancel();                        }                    });                    // 屏蔽keycode等于84之类的按键，避免按键后导致提示消息而页面无法再弹出提示的问题                    builder.setOnKeyListener(new OnKeyListener() {                        @Override                        public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {                            Log.v("onJsConfirm", "keyCode==" + keyCode + "event=" + event);                            return true;                        }                    });                    // 禁止响应按back键的事件                    // builder.setCancelable(false);                    AlertDialog dialog = builder.create();                    dialog.show();                    return true;                }                @Override                public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, final JsPromptResult result) {                    final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());                    builder.setTitle("提示").setMessage(message);                    final EditText et = new EditText(view.getContext());                    et.setSingleLine();                    et.setText(defaultValue);                    builder.setView(et).setPositiveButton("确定", new DialogInterface.OnClickListener() {                        public void onClick(DialogInterface dialog, int which) {                            result.confirm(et.getText().toString());                        }                    })                            .setNeutralButton("取消", new DialogInterface.OnClickListener() {                                public void onClick(DialogInterface dialog, int which) {                                    result.cancel();                                }                            });                    // 屏蔽keycode等于84之类的按键，避免按键后导致提示消息而页面无法再弹出提示的问题                    builder.setOnKeyListener(new OnKeyListener() {                        public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {                            Log.v("onJsPrompt", "keyCode==" + keyCode + "event=" + event);                            return true;                        }                    });                    AlertDialog dialog = builder.create();                    dialog.show();                    return true;                }            };            seckill_webview.setWebChromeClient(wvcc);            extraHeaders = new HashMap<String, String>();            extraHeaders.put("Honorsoft-App", "true");        } catch (Exception e) {            e.printStackTrace();        }        try {            initView();        } catch (Exception e) {            e.printStackTrace();        }    }}