2015-11-19

在Android的webview中定制js的alert,confirm和prompt对话框的方法

1.首先继承android.webkit.WebChromeClient实现MyWebChromeClient。

2.在MyWebChromeClient.java中覆盖onJsAlert,onJsConfirm,onJsPrompt三个方法。

3.在初始化Webview时设置调用webview.setWebChromeClient(new MyWebChromeClient());

4.在Webview载入的html中使用window.alert,window.confirm,window.prompt方法，系统弹出的将是自定义实现的对应对话框。

MyWebChromeClient.java的代码如下：

import android.app.AlertDialog;  
import android.content.DialogInterface;  
import android.content.DialogInterface.OnCancelListener;  
import android.content.DialogInterface.OnClickListener;  
import android.content.DialogInterface.OnKeyListener;  
import android.graphics.Bitmap;  
import android.os.Message;  
import android.util.Log;  
import android.view.KeyEvent;  
import android.webkit.JsPromptResult;  
import android.webkit.JsResult;  
import android.webkit.WebChromeClient;  
import android.webkit.WebView;  
import android.widget.EditText;  
  
/** 
 * http://618119.com/archives/2010/12/20/199.html 
 */  
  
//****************************************************************************  
public class MyWebChromeClient extends WebChromeClient {  
    @Override  
    public void onCloseWindow(WebView window) {  
        super.onCloseWindow(window);  
    }  
  
    @Override  
    public boolean onCreateWindow(WebView view, boolean dialog,  
            boolean userGesture, Message resultMsg) {  
        return super.onCreateWindow(view, dialog, userGesture, resultMsg);  
    }  
  
    /**  
     * 覆盖默认的window.alert展示界面，避免title里显示为“：来自file:////”  
     */  
    public boolean onJsAlert(WebView view, String url, String message,  
            JsResult result) {  
        final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());  
                  
        builder.setTitle("对话框")  
                .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;  
        // return super.onJsAlert(view, url, message, result);  
    }  
  
    public boolean onJsBeforeUnload(WebView view, String url,  
            String message, JsResult result) {  
        return super.onJsBeforeUnload(view, url, message, result);  
    }  
  
    /** 
     * 覆盖默认的window.confirm展示界面，避免title里显示为“：来自file:////” 
     */  
    public boolean onJsConfirm(WebView view, String url, String message,  
            final JsResult result) {  
        final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());  
        builder.setTitle("对话框")  
                .setMessage(message)  
                .setPositiveButton("确定",new OnClickListener() {  
                            public void onClick(DialogInterface dialog,int which) {  
                                result.confirm();  
                            }  
                        })  
                .setNeutralButton("取消", new OnClickListener() {  
                    public void onClick(DialogInterface dialog, int which) {  
                        result.cancel();  
                    }  
                });  
        builder.setOnCancelListener(new OnCancelListener() {  
            @Override  
            public void onCancel(DialogInterface dialog) {  
                result.cancel();  
            }  
        });  
  
        // 屏蔽keycode等于84之类的按键，避免按键后导致对话框消息而页面无法再弹出对话框的问题  
        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;  
        // return super.onJsConfirm(view, url, message, result);  
    }  
  
    /** 
     * 覆盖默认的window.prompt展示界面，避免title里显示为“：来自file:////” 
     * window.prompt('请输入您的域名地址', '618119.com'); 
     */  
    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("对话框").setMessage(message);  
                  
        final EditText et = new EditText(view.getContext());  
        et.setSingleLine();  
        et.setText(defaultValue);  
        builder.setView(et)  
                .setPositiveButton("确定", new OnClickListener() {  
                    public void onClick(DialogInterface dialog, int which) {  
                        result.confirm(et.getText().toString());  
                    }  
          
                })  
                .setNeutralButton("取消", new OnClickListener() {  
                    public void onClick(DialogInterface dialog, int which) {  
                        result.cancel();  
                    }  
                });  
  
        // 屏蔽keycode等于84之类的按键，避免按键后导致对话框消息而页面无法再弹出对话框的问题  
        builder.setOnKeyListener(new OnKeyListener() {  
            public boolean onKey(DialogInterface dialog, int keyCode,KeyEvent event) {  
                Log.v("onJsPrompt", "keyCode==" + keyCode + "event="+ event);  
                return true;  
            }  
        });  
  
        // 禁止响应按back键的事件  
        // builder.setCancelable(false);  
        AlertDialog dialog = builder.create();  
        dialog.show();  
        return true;  
        // return super.onJsPrompt(view, url, message, defaultValue,  
        // result);  
    }  
  
    @Override  
    public void onProgressChanged(WebView view, int newProgress) {  
        super.onProgressChanged(view, newProgress);  
    }  
  
    @Override  
    public void onReceivedIcon(WebView view, Bitmap icon) {  
        super.onReceivedIcon(view, icon);  
    }  
  
    @Override  
    public void onReceivedTitle(WebView view, String title) {  
        super.onReceivedTitle(view, title);  
    }  
  
    @Override  
    public void onRequestFocus(WebView view) {  
        super.onRequestFocus(view);  
    }  
}

webview js alert对话框不能弹出解决办法

在配置了webview的 setting属性后，以前设置的都是可以直接弹出来的，今天写一个小demo时候莫名其妙的发现alert怎么也出来，即使设置了这么多也不行：

webSettings.setJavaScriptEnabled(true);
webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
webSettings.setAllowFileAccess(true);// 设置允许访问文件数据
webSettings.setSupportZoom(true);
webSettings.setBuiltInZoomControls(true);
webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
webSettings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
webSettings.setDomStorageEnabled(true);
webSettings.setDatabaseEnabled(true);

解决办法：
webview只是一个承载体，各种内容的渲染需要使用webviewChromClient去实现，所以set一个默认的基类WebChromeClient就行，代码如下：
mWebView.setWebChromeClient(new WebChromeClient());