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HTML---Android与js交互实例

2015-06-05 09:37 501 查看
Android 中可以通过webview来实现和js的交互,在程序中调用js代码,只需要将webview控件的支持js的属性设置为true

Android(Java)与JavaScript(HTML)交互有四种情况:

1) Android(Java)调用HTML中js代码

2) Android(Java)调用HTML中js代码(带参数)

3) HTML中js调用Android(Java)代码

4) HTML中js调用Android(Java)代码(带参数)

下面示例总结这四种情况,直接上干货:

1) Android(Java)

[java]
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private void showWebView(){ // webView与js交互代码
try {
mWebView = new WebView(this);
setContentView(mWebView);

mWebView.requestFocus();

mWebView.setWebChromeClient(new WebChromeClient(){
@Override
public void onProgressChanged(WebView view, int progress){
JSAndroidActivity.this.setTitle("Loading...");
JSAndroidActivity.this.setProgress(progress);

if(progress >= 80) {
JSAndroidActivity.this.setTitle("JsAndroid Test");
}
}
});

mWebView.setOnKeyListener(new View.OnKeyListener() { // webview can go back
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK && mWebView.canGoBack()) {
mWebView.goBack();
return true;
}
return false;
}
});

WebSettings webSettings = mWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
webSettings.setDefaultTextEncodingName("utf-8");

mWebView.addJavascriptInterface(getHtmlObject(), "jsObj");
mWebView.loadUrl("http://192.168.1.121:8080/jsandroid/index.html");
} catch (Exception e) {
e.printStackTrace();
}
}

private Object getHtmlObject(){
Object insertObj = new Object(){
public String HtmlcallJava(){
return "Html call Java";
}

public String HtmlcallJava2(final String param){
return "Html call Java : " + param;
}

public void JavacallHtml(){
runOnUiThread(new Runnable() {
@Override
public void run() {
mWebView.loadUrl("javascript: showFromHtml()");
Toast.makeText(JSAndroidActivity.this, "clickBtn", Toast.LENGTH_SHORT).show();
}
});
}

public void JavacallHtml2(){
runOnUiThread(new Runnable() {
@Override
public void run() {
mWebView.loadUrl("javascript: showFromHtml2('IT-homer blog')");
Toast.makeText(JSAndroidActivity.this, "clickBtn2", Toast.LENGTH_SHORT).show();
}
});
}
};

return insertObj;
}

2) js(HTML)

[html]
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!-- saved from url=(0032)http://localhost:8080/jsandroid/ -->
<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<meta http-equiv="Expires" content="0">
<meta http-equiv="Pragma" content="no-cache">
<meta http-equiv="Cache-Control" content="no-store,no-cache">
<meta name="Handheldfriendly" content="true">
<meta name="viewport" content="width=100%; initial-scale=1.0; user-scalable=yes">
<meta name="robots" content="all">
<meta name="keywords" contect="doodle, mobile, doodlemobile, game, games">
<meta name="description" content="Make People's Mobile Life More Connected Through Games.">

<title>jsandroid_test</title>

<script type="text/javascript" language="javascript">

function showHtmlcallJava(){
var str = window.jsObj.HtmlcallJava();
alert(str);
}

function showHtmlcallJava2(){
var str = window.jsObj.HtmlcallJava2("IT-homer blog");
alert(str);
}

function showFromHtml(){
document.getElementById("id_input").value = "Java call Html";
}

function showFromHtml2( param ){
document.getElementById("id_input2").value = "Java call Html : " + param;
}
</script>
</head>


<body>

hello IT-homer

<br>
<br>
<br>

<input type="button" value="HtmlcallJava" onclick="showHtmlcallJava()" />
<br>
<input type="button" value="HtmlcallJava2" onclick="showHtmlcallJava2()" />

<br>
<br>
<br>
<br>

<input id="id_input" style="width: 90%" type="text" value="null" />
<br>
<input type="button" value="JavacallHtml" onclick="window.jsObj.JavacallHtml()" />

<br>
<br>
<br>

<input id="id_input2" style="width: 90%" type="text" value="null" />
<br>
<input type="button" value="JavacallHtml2" onclick="window.jsObj.JavacallHtml2()" />

</body>
</html>

3) 运行结果:



4) 代码解析:

(1) 允许Android执行js脚本设置

Android(Java)与js(HTML)交互的接口函数是: mWebView.addJavascriptInterface(getHtmlObject(), "jsObj"); // jsObj 为桥连对象

Android容许执行js脚本需要设置: webSettings.setJavaScriptEnabled(true);

(2) js(HTML)访问Android(Java)代码

js(HTML)访问Android(Java)端代码是通过jsObj对象实现的,调用jsObj对象中的函数,如: window.jsObj.HtmlcallJava()

(3) Android(Java)访问js(HTML)代码

Android(Java)访问js(HTML)端代码是通过loadUrl函数实现的,访问格式如:mWebView.loadUrl("javascript: showFromHtml()");

说明:

1) Android访问url网址,需在AndroidManifest.xml文件,配置容许访问网络的权限:

<uses-permission android:name="android.permission.INTERNET" />

2) Android(Java)调用js(HTML)时,使用的mWebView.loadUrl("javascript: showFromHtml()");函数需在UI线程运行,因为mWebView为UI控件

[java]
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public void JavacallHtml(){
runOnUiThread(new Runnable() {
@Override
public void run() {
mWebView.loadUrl("javascript: showFromHtml()");
Toast.makeText(JSAndroidActivity.this, "clickBtn", Toast.LENGTH_SHORT).show();
}
});
}

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