我只是想将我的 java 应用程序与 webview 上的内容进行通信。
详细来说，可能只是在单击按钮时显示 toast ？
在谷歌上搜索并做了一些研究后，得到以下代码。
P.S:- 我使用的是 Android Studio，是否需要编译任何外部库才能完成任务？还是别的？
以下是我的 WebviewActivity 代码:-
public class WebviewActivity extends AppCompatActivity {
private static final String TAG = "Main";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_webview);
//WebView Object
WebView browser;
browser=(WebView)findViewById(R.id.webView);
//Enable Javascript
browser.getSettings().setJavaScriptEnabled(true);
//Inject WebAppInterface methods into Web page by having Interface 'Android'
browser.addJavascriptInterface(new WebAppInterface(this), "Android");
browser.loadUrl("http://www.somewebsite.com/app/form.html");
}
//Class to be injected in Web page
public class WebAppInterface {
Context mContext;
/** Instantiate the interface and set the context */
WebAppInterface(Context c) {
mContext = c;
}
/**
* Show Toast Message
* @param toast
*/
public void showToast(String toast) {
Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
}
/**
* Show Dialog
* @param dialogMsg
*/
public void showDialog(String dialogMsg){
AlertDialog alertDialog = new AlertDialog.Builder(mContext).create();
// Setting Dialog Title
alertDialog.setTitle("JS triggered Dialog");
// Setting Dialog Message
alertDialog.setMessage(dialogMsg);
// Setting alert dialog icon
//alertDialog.setIcon((status) ? R.drawable.success : R.drawable.fail);
// Setting OK Button
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(mContext, "Dialog dismissed!", Toast.LENGTH_SHORT).show();
}
});
// Showing Alert Message
alertDialog.show();
}
/**
* Intent - Move to next screen
*/
public void moveToNextScreen(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("Alert");
// Setting Dialog Message
alertDialog.setMessage("Are you sure you want to leave to next screen?");
// Setting Positive "Yes" Button
alertDialog.setPositiveButton("YES",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//Move to Next screen
}
});
// Setting Negative "NO" Button
alertDialog.setNegativeButton("NO",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Cancel Dialog
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
}
}
form.html:-
<html>
<head>
<style>
body{
background-color: #FA5858;
color:#fff;
}
input{
background-color: #F7D358;
width: 300px;
padding:10px;
color: #000;
}
div#content{
padding:20px;
background-color: #F7D358;
color: #000;
}
</style>
<script type="text/javascript">
function showAndroidToast(toastmsg) {
Android.showToast(toastmsg);
}
function showAndroidDialog(dialogmsg) {
Android.showDialog(dialogmsg);
}
function moveToScreenTwo() {
Android.moveToNextScreen();
}
</script>
</head>
<body>
<center>
<h3>Binding JavaScript code to Android code</h3>
<div id="content">
//some content here
</div>
<div>
Here are few examples:
</div>
<div>
<input type="button" value="Make Toast" onClick="showAndroidToast('Toast made by Javascript')" /><br/>
<input type="button" value="Trigger Dialog" onClick="showAndroidDialog('This dialog is triggered by Javascript ')" /><br/>
<input type="button" value="Take me to Next Screen" onClick="moveToScreenTwo()" />
</div>
</center>
</body>
</html>
我有上面的代码，但它不能在 android-studio 中工作，尝试了所有的可能性，所以最后在这里发布了我的问题。
我对此的研究:-
https://developer.android.com/guide/webapps/webview.html
https://developer.android.com/reference/android/webkit/WebView.html
http://stackoverflow.com/questions/4325639/android-calling-javascript-functions-in-webview
最佳答案
WebAppInterface 类中的方法缺少 @JavascriptInterface 注释。
你的 WebAppInterface 类应该是这样的，
public class WebAppInterface {
Context mContext;
WebAppInterface(Context c) {
mContext = c;
}
@JavascriptInterface
public void showToast(String toast) {
}
@JavascriptInterface
public void showDialog(String dialogMsg){
}
@JavascriptInterface
public void moveToNextScreen(){
}
}
编辑
在将网页内容加载到 WebView 时，请不要忘记将您的应用限制为 API17+，否则您的应用将容易受到攻击。阅读下面@Robert 的评论。
关于javascript - 在 android 中使用 Javascript 桥，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39657311/