Android WebView与JS页面相互调用之onJsAlert+onJsConfirm+onJsPrompt方法详解
本章节讲述 Android WebView 的WebChromeClient 的onJsAlert()、onJsConfirm()、onJsPrompt()方法回调拦截JS对话框alert()、confirm()、prompt() 消息的操作
步骤1：先往assets目录下塞一个html文件： javascript.html
<html>
<head>
<meta http-equiv = "Content-Type" content="text/html;charset=UTF-8"
<title>测试Js的三种不同对话框</title>
<script language="JavaScript">
function alertFun()
{
alert("Alert警告对话框!");
}
function confirmFun()
{
if(confirm("访问百度?"))
{location.href = "http://www.baidu.com";}
else alert("取消访问!");
}
function promptFun()
{
var word = prompt("Prompt对话框","请输入点什么...:");
if(word)
{
alert("你输入了:"+word)
}else{alert("呵呵,你什么都没写!");}
}
</script>
</head>
<body>
<p>三种对话框的使用</p>
<p>Alert对话框</p>
<p>
<input type="submit" name = "Submit1" value="展示1" onclick="alertFun()"/>
</p>
<p>Confirm对话框</p>
<p>
<input type="submit" name = "Submit2" value="展示2" onclick="confirmFun()"/>
</p>
<p>Prompt对话框</p>
<p>
<input type="submit" name = "Submit3" value="展示3" onclick="promptFun()"/>
</p>
</body>
</html>
步骤2：代码实现
webView=findViewById(R.id.activity_webview_webview);
//获得WebSetting对象,支持js脚本,可访问文件,支持缩放,以及编码方式
WebSettings webSettings = webView.getSettings();
webSettings.setJavaScriptEnabled(true);
webSettings.setAllowFileAccess(true);
webSettings.setBuiltInZoomControls(true);
webSettings.setDefaultTextEncodingName("UTF-8");
//设置WebChromeClient,处理网页中的各种js事件
webView.setWebChromeClient(new MyWebChromeClient());
webView.loadUrl("file:///android_asset/javascript.html");
private class MyWebChromeClient extends WebChromeClient{
@Override
public boolean onJsAlert(WebView view, String url, String message, final JsResult result) {
//创建一个Builder来显示网页中的对话框
new AlertDialog.Builder(WebViewActivity2.this).setTitle("Alert对话框").setMessage(message+"AlertMessage")
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.confirm();
}
}).setCancelable(false).show();
return true;
}
@Override
public boolean onJsConfirm(WebView view, String url, String message, final JsResult result) {
new AlertDialog.Builder(WebViewActivity2.this).setTitle("Confirm对话框").setMessage(message+"ConfirmMessage")
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.confirm();
}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.cancel();
}
}).setCancelable(false).show();
return true;
}
@Override
public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, final JsPromptResult result) {
//①获得一个LayoutInflater对象factory,加载指定布局成相应对象
final LayoutInflater inflater = LayoutInflater.from(WebViewActivity2.this);
final View myview = inflater.inflate(R.layout.prompt_view, null);
//设置TextView对应网页中的提示信息,edit设置来自于网页的默认文字
((TextView) myview.findViewById(R.id.text)).setText(message);
((EditText) myview.findViewById(R.id.edit)).setText(defaultValue);
//定义对话框上的确定按钮
new AlertDialog.Builder(WebViewActivity2.this).setTitle("Prompt对话框").setView(myview)
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
//单击确定后取得输入的值,传给网页处理
String value = ((EditText) myview.findViewById(R.id.edit)).getText().toString();
result.confirm(value+"PromptMessage");
}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.cancel();
}
}).show();
return true;
}
}
运行效果：