部分语句Inject会失效

[lizhangqu]

比如if当前行，forin当前行和循环体内代码，for当前行和循环体内代码都无法Inject代码，见下面的case

    int a = 10;
    if (a > 5) {
      print('[KWLM]:if1');
    }
    print('[KWLM]:a');
    for (Observer o in observers) {
      print('[KWLM]:Observer1');
      o.onChanged();
      print('[KWLM]:Observer2');
    }
    print('[KWLM]:b');
    for (int i = 0; i < 10; i++) {
      print('[KWLM]:for i $i');
      print('[KWLM]:for i $i');
    }
    print('[KWLM]:c');

if (a > 5) 这一行前面即int a = 10;这一行后面无法用Inject注入代码

for (Observer o in observers) {这一行前面即print('[KWLM]:a');这一行后面无法用Inject注入代码

循环体内无法用Inject注入代码

    for (Observer o in observers) {
      print('[KWLM]:Observer1');
      o.onChanged();
      print('[KWLM]:Observer2');
    }

for (int i = 0; i < 10; i++) {这一行前面即print('[KWLM]:b');这一行后面无法用Inject注入代码

循环体内无法用Inject注入代码

    for (int i = 0; i < 10; i++) {
      print('[KWLM]:for i $i');
      print('[KWLM]:for i $i');
    }

可能和这个函数没有处理for循环有关：

 static Node getNodeToVisitRecursively(Object statement) {
    if (statement is FunctionDeclaration) {
      return statement.function;
    }
    if (statement is LabeledStatement) {
      return statement.body;
    }
    if (statement is IfStatement) {
      return statement.then;
    }
    return null;
  }

可以在Inject注解上增加后向插入

if (statement2InsertPos != -1) {
          _curAopStatementsInsertInfo = null;
          statements.insertAll(statement2InsertPos, aopInsertStatements);
          _curAopLibrary = aopItemInfo.aopMember?.parent?.parent;
          visitNode(node);
          break;
}

后向插入取statement2InsertPos+1
这样就能在if语句和for循环语句前面一行插入，即插入上一行的后面。

[kangwang1988]

@lizhangqu
Thanks for your feedback.
It would be appreciated if a minimal demo project to help reproduce this issue is given.
Besides, I would like to review it if you would like to file a pr.