Android通过WebView调用 JS 代码
a. webView.loadUrl("javascript:callJS()");
b. setWebChromeClient响应弹窗
1.布局
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:layout_editor_absoluteX="136dp"
tools:layout_editor_absoluteY="0dp"
android:orientation="vertical"
tools:ignore="MissingConstraints">
<WebView
android:id="@+id/webview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1">
</WebView>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:layout_weight="3">
<Button
android:id="@+id/btnLeft"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="左边" />
<EditText
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="0"/>
<Button
android:id="@+id/btnRight"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="右边" />
</LinearLayout>
</LinearLayout>
</android.support.constraint.ConstraintLayout>
2.index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Carson_Ho</title>
// JS代码
<script>
// Android需要调用的方法
function callJS(){
document.getElementById("test").innerHTML = "android button 点击左边 实现'webView.loadUrl('javascript:callJS()');'就可以响应";
alert("Android调用了JS的callJS方法 实现‘webView.setWebChromeClient’才有响应");
}
</script>
</head>
<body>
<div id="test"> 0000000000 </div>
</body>
</html>
3.java
public class MainActivity extends Activity {
WebView webView;
Button buttonLeft, buttonRight;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webView = findViewById(R.id.webview);
buttonLeft = findViewById(R.id.btnLeft);
buttonRight = findViewById(R.id.btnRight);
WebSettings webSettings = webView.getSettings();
//允许使用JS
webSettings.setJavaScriptEnabled(true);
// 设置允许JS弹窗
webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
webView.loadUrl("file:///android_asset/index.html");
buttonLeft.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
webView.post(new Runnable() {
@Override
public void run() {
webView.loadUrl("javascript:callJS()");
}
});
}
});
webView.setWebChromeClient(new WebChromeClient() {
@Override
public boolean onJsAlert(WebView view, String url, String message, final JsResult result) {
AlertDialog.Builder b = new AlertDialog.Builder(MainActivity.this);
b.setTitle("alert1");
b.setMessage(message);
b.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
result.confirm();
}
});
b.setCancelable(false);
b.create().show();
return true;
}
});
}
}
