Android HTML 按钮 onclick 事件

Question

I have images displaying in Local HTML pages and have one button for click event.我在本地 HTML 页面中显示了图像，并且有一个用于单击事件的按钮。 When click this button i need to call another activity.单击此按钮时，我需要调用另一个活动。 It's working.它正在工作。 But the issue is after going another then come back to HTML pages the images are not displaying and app is not working.但问题是再去一次，然后回到 HTML 页面，图像未显示且应用程序无法运行。

<script language="javascript">
function validClick() {
    valid.performClick();
    document.getElementById("ok").value = "start";
}
function refuseClick(){
    refuse.performClick();
    document.getElementById("no").value = "Je refuse";
}

<div>
<button type="button" id="ok"
    style="font-weight: 700; margin-right: 20px;" onclick="validClick();">Start</button>

</div>

HTML page contain image: HTML 页面包含图像：

<li><a class="box" href="products.html" data-transition="fade" > <img src="img/products.png" alt="Products"> <span class="text"> Products</span>

MainActivity:主要活动：

public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.about_screen);


        WebView  webview = (WebView) findViewById(R.id.webview);
        webview.loadUrl("file:///android_asset/index.html");

        valid = new Button(this);
        valid.setOnClickListener(this);
        refuse = new Button(this);
        refuse.setOnClickListener(this);

     // Enablejavascript
        WebSettings ws = webview.getSettings();
        ws.setJavaScriptEnabled(true);
        // Add the interface to record javascript events
        webview.addJavascriptInterface(valid, "valid");
        webview.addJavascriptInterface(refuse, "refuse");

 }


    @Override
    public void onClick(View v) {
        if (v.equals(valid)) {

        Intent i = new Intent(this, CloudReco.class);
        startActivity(i);
        } else if (v.equals(refuse)) {
            //do Something else }
    }

Answer 1

There are a few things you need to check with your code.您需要检查代码中的一些事项。

First, in your HTML, the <script> tag at the top is not closed.首先，在您的 HTML 中，顶部的<script>标记没有关闭。 Please add a </script> after your last function definition.请在最后一个函数定义后添加一个</script> 。

Second, in the Java, please configure your WebView before calling loadUrl .其次，在 Java 中，请在调用loadUrl之前配置您的 WebView。 Settings and JavaScript interfaces should be registered first.应首先注册设置和 JavaScript 接口。

Third, there's no need to use a Button widget to achieve the effect you are looking for.第三，没有必要使用Button小部件来实现您正在寻找的效果。 Something like this should be perfectly adequate:像这样的东西应该是完全足够的：

webview.addJavaScriptInterface(new Object() {
    @JavaScriptInterface
    public void performClick() {
        Intent i = new Intent(this, CloudReco.class);
        startActivity(i);
    }
}, "valid");

and similar for "refuse".和“拒绝”类似。

Answer 2

The next "strange" method I've used to pass a lot of javascript event (last use was fro scroll event and I was passing also the value concatenated):我用来传递大量 javascript 事件的下一个“奇怪”方法（上次使用的是滚动事件，我还传递了串联的值）：

webView.setWebViewClient(new WebViewClient() {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        if (url.contains("button1Event")) {
            // button1 was clicked inside webview html
            Toast.makeText(context, "Button1WasClicked", Toast.LENGTH_SHORT).show();  
            return true; //(to avoid a default redirect to the url)
         } else if (url.contains("button2Event")) {
            // button2 was clicked inside webview html
            Toast.makeText(context, "Button2WasClicked", Toast.LENGTH_SHORT).show();  
            return true; //(to avoid a default redirect to the url)
         }
         return false;
      }
}

HTML contains a dummy <a> element used to simulate the URLclick where URL is a KEY that we are waiting in Native code: HTML 包含一个虚拟的<a>元素，用于模拟 URLclick，其中 URL 是我们在本机代码中等待的 KEY：

<!DOCTYPE html>
<html>
<body>
<a id='yourLinkID'></a>

<button onclick="myFunction('button1Event')">Button1</button>
<button onclick="myFunction('button2Event')">Button2</button>

<script>
function myFunction(value) {
    document.getElementById('yourLinkID').href = 'testtest' + value; 
    document.getElementById('yourLinkID').click();
// we set the wanted URL and simulate the click
}
</script>

</body>
</html>

Android HTML 按钮 onclick 事件

问题描述

2 个解决方案

解决方案1
3 2014-03-03 21:26:57

解决方案2
-1 2016-01-27 12:41:53

Android HTML 按钮 onclick 事件

问题描述

2 个解决方案

解决方案1 3 2014-03-03 21:26:57

解决方案2 -1 2016-01-27 12:41:53

解决方案1
3 2014-03-03 21:26:57

解决方案2
-1 2016-01-27 12:41:53