调整了一些方法调用

Author: CarGuo

lib/common/ab/SqlManager.dart

@@ -59,9 +59,7 @@ class SqlManager {
 
   ///关闭
   static close() {
-    if (_database != null) {
-      _database.close();
+      _database?.close();
       _database = null;
-    }
   }
 }

lib/widget/GSYFlexButton.dart

@@ -35,9 +35,7 @@ class GSYFlexButton extends StatelessWidget {
           children: <Widget>[new Text(text, style: new TextStyle(fontSize: fontSize), maxLines: maxLines, overflow:TextOverflow.ellipsis)],
         ),
         onPressed: () {
-          if (this.onPress != null) {
-            this.onPress();
-          }
+          this.onPress?.call();
         });
   }
 }

lib/widget/GSYPullLoadWidget.dart

@@ -46,8 +46,8 @@ class _GSYPullLoadWidgetState extends State<GSYPullLoadWidget> {
     _scrollController.addListener(() {
       ///判断当前滑动位置是不是到达底部，触发加载更多回调
       if (_scrollController.position.pixels == _scrollController.position.maxScrollExtent) {
-        if (this.onLoadMore != null && this.control.needLoadMore) {
-          this.onLoadMore();
+        if (this.control.needLoadMore) {
+          this.onLoadMore?.call();
         }
       }
     });

lib/widget/GSYSearchDrawer.dart

@@ -107,9 +107,7 @@ class _GSYSearchDrawerState extends State<GSYSearchDrawer> {
             }
             list[index].select = true;
           });
-          if (select != null) {
-            select(model.value);
-          }
+          select?.call(model.value);
         },
         child: new Container(
           width: itemWidth,

lib/widget/GSYSelectItemWidget.dart

@@ -64,10 +64,8 @@ class _GSYSelectItemWidgetState extends State<GSYSelectItemWidget> {
             textAlign: TextAlign.center,
           ),
           onPressed: () {
-            if (selectItemChanged != null) {
-              if (selectIndex != index) {
-                selectItemChanged(index);
-              }
+            if (selectIndex != index) {
+              selectItemChanged?.call(index);
             }
             setState(() {
               selectIndex = index;

lib/widget/GSYTabBarWidget.dart

@@ -128,9 +128,7 @@ class _GSYTabBarState extends State<GSYTabBarWidget> with SingleTickerProviderSt
           children: _tabViews,
           onPageChanged: (index) {
             _tabController.animateTo(index);
-            if (_onPageChanged != null) {
-              _onPageChanged(index);
-            }
+            _onPageChanged?.call(index);
           },
         ),
       );

lib/widget/IssueEditDIalog.dart

@@ -87,9 +87,7 @@ class _IssueEditDialogState extends State<IssueEditDialog> {
                 setState(() {
                   valueController.value = new TextEditingValue(text: newText);
                 });
-                if (onContentChanged != null) {
-                  onContentChanged(newText);
-                }
+                onContentChanged?.call(newText);
               });
         },
         itemCount: FAST_INPUT_LIST.length,

lib/widget/UserHeader.dart

@@ -70,9 +70,7 @@ class UserHeaderItem extends StatelessWidget {
         ),
         onPressed: () {
           NavigatorUtils.goNotifyPage(context).then((res) {
-            if (refreshCallBack != null) {
-              refreshCallBack();
-            }
+            refreshCallBack?.call();
           });
         });
   }