please a error when I try to reload my webview from a button : E/flutter (18150): [ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: Null check operator used on a null value
RaisedButton(
padding: const EdgeInsets.symmetric(vertical: 10,horizontal: 30),
onPressed: () async {
controller.reload();
},
this is my WebView
WebView(
initialUrl: "https://wikoget.com",
javascriptMode: JavascriptMode.unrestricted,
onWebViewCreated: (controller){
this.controller=controller;
},
onPageFinished: (String url) {
controller
.evaluateJavascript("javascript:(function() { " +
"var head = document.getElementsByClassName('main-header-bar-wrap')[0];" +
"head.parentNode.style.cssText = ' position: sticky;position: -webkit-sticky; top : 0 ';" +
"var footer = document.getElementsByTagName('footer')[0];" +
"footer.parentNode.removeChild(footer);" +
"})()")
.then((value) => debugPrint('Page finished loading Javascript'));
},
onWebResourceError: (error) => setState(() {
controller.loadUrl("about:blank");
isError = true;
}),
gestureNavigationEnabled: true,
),
enter code hereUse the fallback operator to set a default value for null values before using the variable.
String? str; //nullable value
str ??= "Fallback Value";
print(str); //Output: Fallback Value
Here, "str" is null, and we set the fallback operator with fallback value in case of "str" is null.