There are many packages to implement such functionality, but in this example we use flutter_inappwebview package.
Step 1 : Add dependency to pubspec.yaml
flutter_inappwebview: ^6.0.0
Step 2 : Create an assets folder in project root directory and create index.html file.
Add HTML content inside file.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>InAppWebView Example</title>
<style>
body {
font-family: Arial, sans-serif;
background-color: #f4f4f4;
margin: 0;
padding: 0;
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
}
.container {
background-color: #fff;
padding: 20px;
box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
border-radius: 8px;
max-width: 400px;
width: 100%;
text-align: center;
}
h1 {
color: #333;
font-size: 24px;
margin-bottom: 20px;
}
input[type="number"] {
width: 100%;
padding: 10px;
margin: 10px 0;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
}
button {
background-color: #007bff;
color: white;
padding: 12px 20px;
margin-top: 10px;
border: none;
border-radius: 4px;
font-size: 16px;
cursor: pointer;
width: 100%;
}
button:hover {
background-color: #0056b3;
}
p {
font-size: 18px;
margin-top: 20px;
color: #333;
}
.result {
font-weight: bold;
color: #007bff;
}
</style>
<script type="text/javascript">
function callFlutterSum() {
var num1 = parseInt(document.getElementById("num1").value);
var num2 = parseInt(document.getElementById("num2").value);
window.flutter_inappwebview.callHandler('mySum', num1, num2).then(function(result) {
document.getElementById("result").innerHTML = "Sum from Flutter: <span class='result'>" + result + "</span>";
});
}
</script>
</head>
<body>
<div class="container">
<h1>InAppWebView Example</h1>
<input type="number" id="num1" placeholder="Enter first number">
<input type="number" id="num2" placeholder="Enter second number">
<button onclick="callFlutterSum()">Get Sum from Flutter</button>
<p id="result"></p>
</div>
</body>
</html>
- Here we added the initial file.
- It provides various callbacks onLoadStarted, onLoadStop, OnConsoleMessage and onWebViewCreated.
- We are added handler inside onWebViewCreated callback.
- We added mySum handler and return value to JavaScript side.
Output:
Support On Demand!
