Android (ICS)：在修改 window.location 的 HTML/JS 中使用 loadData 时，WebView 无法显示

发布于 2025-01-06 10:52:23 字数 2382 浏览 4 评论 0原文

在传递特定 HTML 有效负载时，我在使用 WebView 的 loadData 方法时遇到问题。有效负载包含一些 JavaScript，用于将 window.location 设置为具有自定义方案的 URL（以下示例中的 mycustomscheme://）。原因是我希望我的应用程序代码能够在 shouldOverrideUrlLoading 的实现中捕获各种 JS 事件。

在我的 Galaxy Nexus 设备（运行 Ice Cream Sandwich）上，shouldOverrideUrlLoading 按预期工作，但 WebView 从未出现在屏幕上。如果我从 JS 中删除 window.location 代码，WebView 就会正常显示。该代码似乎也可以在我尝试过的所有 ICS 之前的设备上正常工作。

我在下面的代码中遗漏了一些明显的东西吗？

编辑： 我可以使用 addJavascriptInterface 来完成同样的事情，但我不想这样做，因为并非所有 HTML 都是由我生成的。为了保持代码示例的清晰性，我省略了这个细节。

public class ICSWebViewTestActivity extends Activity {
    private RelativeLayout mLayout;
    private WebView mWebView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mLayout = new RelativeLayout(this);
        mLayout.setBackgroundColor(Color.RED);
        setContentView(mLayout);

        mWebView = new WebView(this);
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.setBackgroundColor(Color.GREEN);
        mWebView.setWebViewClient(new MyWebViewClient());

        String data = 
            "<html><head>" +
            "<script>" +
            "window.onload = f;" + // works if this line is removed
            "function f() { window.location = 'mycustomscheme://finish'; }" + 
            "</script>" +
            "</head>" +
            "<body><h1 style='color:blue'>Hello, world!</h1></body>";

        mWebView.loadData(data, "text/html", "utf-8");

        RelativeLayout.LayoutParams rlp = new RelativeLayout.LayoutParams(
                RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
        rlp.addRule(RelativeLayout.CENTER_IN_PARENT);

        mLayout.addView(mWebView, rlp);
    }

    private void doAction() {
        Toast.makeText(this, "Doing action!", Toast.LENGTH_SHORT).show();
    }

    private class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            if (url.startsWith("mycustomscheme://")) {
                doAction();
            }
            return true;
        }
    }
}

原文

I'm experiencing trouble with WebView's loadData method when passing in a certain HTML payload. The payload contains some JavaScript that sets window.location to a URL with a custom scheme (mycustomscheme:// in the example below). The reason for this is that I'd like my application code to be able to catch various JS events in its implementation of shouldOverrideUrlLoading.

On my Galaxy Nexus device (running Ice Cream Sandwich), shouldOverrideUrlLoading works as intended, but the WebView doesn't ever appear on-screen. If I remove the window.location code from the JS, the WebView shows up just fine. The code also seems to work correctly on all pre-ICS devices I've tried.

Am I missing something obvious in the code below?

Edit: I could use addJavascriptInterface to accomplish the same thing, but I'd prefer not to do that, since not all of the HTML is generated by me. To preserve the clarity of the code sample, I've omitted this detail.

public class ICSWebViewTestActivity extends Activity {
    private RelativeLayout mLayout;
    private WebView mWebView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mLayout = new RelativeLayout(this);
        mLayout.setBackgroundColor(Color.RED);
        setContentView(mLayout);

        mWebView = new WebView(this);
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.setBackgroundColor(Color.GREEN);
        mWebView.setWebViewClient(new MyWebViewClient());

        String data = 
            "<html><head>" +
            "<script>" +
            "window.onload = f;" + // works if this line is removed
            "function f() { window.location = 'mycustomscheme://finish'; }" + 
            "</script>" +
            "</head>" +
            "<body><h1 style='color:blue'>Hello, world!</h1></body>";

        mWebView.loadData(data, "text/html", "utf-8");

        RelativeLayout.LayoutParams rlp = new RelativeLayout.LayoutParams(
                RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
        rlp.addRule(RelativeLayout.CENTER_IN_PARENT);

        mLayout.addView(mWebView, rlp);
    }

    private void doAction() {
        Toast.makeText(this, "Doing action!", Toast.LENGTH_SHORT).show();
    }

    private class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            if (url.startsWith("mycustomscheme://")) {
                doAction();
            }
            return true;
        }
    }
}

分享到QQ

分享到微博