there is no default constructor available in 原因 这个错误是由于继承引起的,原因是子类里写了并且使用了无参的构造方法(不写默认就是无参的构造方法),但是它的父类中却至少有一个是没有“无参构造方法”的,就会出现这个问题 总结 一个类如果显式的定义了带参构造函数,那么默认无参构造函数自动失效 一个类...
//父类 public class AA { public AA(String s){ } } //子类 public class AA1 extends AA{ //没有这个构造函数,会报错:There is no default constructor available in ... public AA1(String s) { super(s); } } 一个类如果显式的定义了带参构造函数,也显示的定义了无参构造函数.那么这个类的...
there is no default constructor available in ... Java写继承子类的时候报错There is no default constructor available in ‘子类名’ 最近因为工作需要,不得不开始学习Java,跟着教程学习过程中也遇到了不少的问题,在这里总结记录一下。 我写了一个父类,在写继承子类的时候出现的报错,父类代码如下: Google了一...
Peter Molettiere on Apple's Java forum gave excellent answers: Because there is no default constructor available in B, as the compiler error message indicates. Once you define a constructor in a class, the default constructor is** not included.** If you defineanyconstructor, then you must de...
surper(context,attrs,deefStyle); super(context,attrs,deefStyle);super写错了，别的没问题
参考网址:https://blog.csdn.net/m0_38021517/article/details/73647707 也就是说一个类中,如果你不进行显示的创建构造方法,那么他是会自带一个无参数构造方法的。如果你有显示的创建了带参数的构造方法,那么如果不显示的指定无参数构造方法的话,那么无参
Implicit super constructor Object() is undefined for default constructor 新建类后报红点问题,及没有成功的导入包 新建class后出现的问题。我解决过一次,现在从开始创建一个class: 事实证明好了,那么一开始要如何改呢: 1.找到java build path: 再找到libraries,把错误的删除,点击add libr...androidx.appcompat...
操作时出现There is no default constructor available in android.view.view是为什么呢?1 2 public class WuziqiPanel extends View {慕粉2235156905 2017-02-17 源自:Android-五子连珠 2-1 关注问题 我要回答 8559 分享 操作 收起 1 回答瘦瘦的胖哥 2017-02-23 构造方法最好这样写 1 2 3 4 5 6 7 8 ...
The class is expected to follow a specific design pattern and include, for example, a parameterless constructor and methods with a well-known behavior. SqlDataSource Represents a connection to an ADO.NET data provider that returns SQL data, including data sources accessible through OLE DB and ...
Scope 'request' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual...