fix: reloadUrl will not return Future

android/src/main/java/com/flutter_webview_plugin/FlutterWebviewPlugin.java

@@ -147,6 +147,7 @@ public class FlutterWebviewPlugin implements MethodCallHandler, PluginRegistry.A
         if (webViewManager != null) {
             webViewManager.stopLoading(call, result);
         }
+        result.success(null);
     }
 
     private void close(MethodCall call, MethodChannel.Result result) {
@@ -163,6 +164,7 @@ public class FlutterWebviewPlugin implements MethodCallHandler, PluginRegistry.A
         if (webViewManager != null) {
             webViewManager.back(call, result);
         }
+        result.success(null);
     }
 
     /**
@@ -172,6 +174,7 @@ public class FlutterWebviewPlugin implements MethodCallHandler, PluginRegistry.A
         if (webViewManager != null) {
             webViewManager.forward(call, result);
         }
+        result.success(null);
     }
 
     /**
@@ -181,6 +184,7 @@ public class FlutterWebviewPlugin implements MethodCallHandler, PluginRegistry.A
         if (webViewManager != null) {
             webViewManager.reload(call, result);
         }
+        result.success(null);
     }
 
     private void reloadUrl(MethodCall call, MethodChannel.Result result) {
@@ -188,6 +192,7 @@ public class FlutterWebviewPlugin implements MethodCallHandler, PluginRegistry.A
             String url = call.argument("url");
             webViewManager.reloadUrl(url);
         }
+        result.success(null);
     }
 
     private void eval(MethodCall call, final MethodChannel.Result result) {
@@ -208,12 +213,14 @@ public class FlutterWebviewPlugin implements MethodCallHandler, PluginRegistry.A
         if (webViewManager != null) {
             webViewManager.hide(call, result);
         }
+        result.success(null);
     }
 
     private void show(MethodCall call, final MethodChannel.Result result) {
         if (webViewManager != null) {
             webViewManager.show(call, result);
         }
+        result.success(null);
     }
 
     private void cleanCookies(MethodCall call, final MethodChannel.Result result) {