activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context=".MainActivity">
<WebView
android:id="@+id/web_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone">
</WebView>
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="调用JS代码"/>
</LinearLayout>
MainActivity.java
package com.example.webviewtest;
public class MainActivity extends AppCompatActivity {
private WebView mWebView;
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mWebView = findViewById(R.id.web_view);
WebSettings webSettings = mWebView.getSettings();
//设置与JS交互的权限
webSettings.setJavaScriptEnabled(true);
//设置允许JS弹窗
webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
//先载入JS代码
mWebView.loadUrl("http://192.168.17.xx:8081/hello.html");
button = findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//通过Handler发送消息
mWebView.post(new Runnable() {
@Override
public void run() {
//调用Js中的 hello()方法
mWebView.loadUrl("javascript:hello()");
}
});
}
});
//由于设置了弹窗检验调用结果，所以需要支持js对话框
//webview只是载体，内容的渲染需要使用webviewChromClient类去实现
//通过设置WebChromeClient对象处理JavaScript的对话框
//设置响应js的Alert()函数
mWebView.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("Alert");
b.setMessage(message);
b.setPositiveButton("ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.confirm();
}
});
b.setCancelable(false);
b.create().show();
return true;
}
});
}
}
服务器端的 Js 方法
<script>
function hello() {
alert("Hello World！");
}
</script>
