eclipse .java 不使用 2 或 3 参数视图构造函数；XML 属性不起作用
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.java not using the 2- or 3-argument View constructors; XML attributes will not work
提问by xsxy
i'm newbie i have problem creating game
我是新手我在创建游戏时遇到问题
execute process
执行过程
activity_main.xml -> MainActivity.java -> GameLoop.java -> action.xml (error) -> CustomView.java
activity_main.xml -> MainActivity.java -> GameLoop.java -> action.xml (error) -> CustomView.java
Custom view CustomView is not using the 2- or 3-argument View constructors; XML attributes will not work
I don't understand......
我不明白……
回答by Andy McSherry
You need to override the other 2 constructors of View in CustomView:
您需要在 CustomView 中覆盖 View 的其他 2 个构造函数：
public CustomView(Context context) {
super(context);
init(context);
}
public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public CustomView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
private void init(Context context) {
//do stuff that was in your original constructor...
}
回答by Trevor
You need to implement these constructors also:
您还需要实现这些构造函数：
//Constructor that is called when inflating a view from XML.
View(Context context, AttributeSet attrs)
//Perform inflation from XML and apply a class-specific base style.
View(Context context, AttributeSet attrs, int defStyle)
回答by bianchi
I think it depends how You creating Your custom view and how You gonna use it
.
Not all 3 constructors really necessary.
If You create the view with attributes xml file, but won't use defstyle, its enough to call
我认为这取决于您如何创建自定义视图以及您将如何使用它。
并非所有 3 个构造函数都真正必要。
如果您使用属性 xml 文件创建视图，但不会使用 defstyle，则足以调用
public CustomView(Context context, AttributeSet attrs) {
this(context, attrs);
//Your code
}
if You not using attributes and defstlye /i saw examples for this/ You happy to call only
如果你不使用属性和 defstlye /我看到了这个例子/你很乐意只打电话
public CustomView(Context context) {
super(context);
//Your code
}
and if You want use defstyle and attributes too
如果你也想使用 defstyle 和属性
public CustomView(Context context, AttributeSet attrs) {
this(context, attrs);
//Yourcode
}
回答by Tzegenos
In case someone works with Kotlin he/she can do that:
如果有人使用 Kotlin，他/她可以这样做：
class KotlinView @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr)
You can find this solution and more details here: https://antonioleiva.com/custom-views-android-kotlin/
您可以在此处找到此解决方案和更多详细信息：https: //antonioleiva.com/custom-views-android-kotlin/
