JavaFX WebView Progress总是从0.0到1.0。 （没有中间值） [英] JavaFX WebView Progress always goes from 0.0 to 1.0. (No intermediate values)

问题描述

我目前正在使用GluonHQ（JavaFXPorts）开发一个应用程序，我正在使用WebView加载一些Internet页面。我注意到当我在桌面上使用以下代码时

I am currently developing an application with GluonHQ (JavaFXPorts) where I am using the WebView to load some Internet pages. I have noticed that when I am using the following code on Desktop

webEngine.getLoadWorker().progressProperty().addListener((a,b,progress) -> System.out.println(": " +progress.doubleValue()));

它打印出从0.0到1.0的加载。

it prints out the loading from 0.0 to 1.0.

Loading Page: 0.0
Loading Page: 0.22
Loading Page: 0.38
Loading Page: 0.81
Loading Page: 1.0

虽然在iOS上它总是返回0.0和1.0，而不是任何中间值。

Whilst on iOS it always returns 0.0 and 1.0, not any intermediate values.

Loading Page: 0.0
Loading Page: 1.0

有办法解决这个问题吗？

Any way to handle this?

推荐答案

使用JavaFXPorts，在移动设备（Android和iOS）上， WebView 控件不是JavaFX内置控件，而是本机控件。例如，在iOS上，使用 UIWebView 控件。顺便说一句，同样适用于 TextField 和 TextArea 控件。

With JavaFXPorts, on mobile (both Android and iOS) the WebView control is not the JavaFX built-in control but the native control. For instance, on iOS, a UIWebView control is used. Same applies to TextField and TextArea controls, by the way.

为了保持与桌面相同的API，JavaFXWebView控件，但它只是一个外观，一个具有相同属性但没有webKit的节点。一切都传递给本机控件。

To keep the same API as in desktop, a JavaFX "WebView" control is used, but it is just a facade, a node with same properties, but without webKit. Everything is passed down to the native control.

虽然本机层和Java层之间存在双向通信，但不发送所有，因此没有1：1本机控件属性与桌面实现的JavaFX属性之间的关系。

And while there is communication in both ways between the native and the Java layers, not everything is sent, so there is no 1:1 relation between the native control properties and the JavaFX properties of the desktop implementation.

如果检查原生实现，你可以找到一些与加载状态和本机回调相关的方法：

If you check the native implementation in Objective-C for iOS, you can find some methods related to the loading status, and the native callbacks:

- (void)webViewDidStartLoad:(UIWebView *)webView {
    ...
    (*env)->CallVoidMethod(env, jObject, jmidLoadStarted);
}
- (void)webViewDidFinishLoad:(UIWebView *)wv {
    ...
    (*env)->CallVoidMethod(env, jObject, jmidLoadFinished, jUrl, jInner);
}

转到JavaFX control ：

// native callbacks
private void notifyLoadStarted() {
    engine.notifyLoadStarted();
}

private void notifyLoadFinished(String loc, String content) {
    engine.notifyLoadFinished(loc, content);
}

如您所见，没有与加载进度相关的方法，所以这就是你不会获得任何中间价值的原因。

As you can see, there is no method related to the loading progress, so that is the reason you won't get any intermediate value.

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