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Clojure 向 JPanel 添加边框并通常访问对象中的 java 方法

发布于 2024-12-20 03:21:17 字数 2185 浏览 2 评论 0 原文

来自 LISP 的我在访问 java 对象时遇到了最具挑战性的时刻。我正在尝试在 JPanel 上添加标题边框。这是我的代码和例外：

user=> (import '(javax.swing JComponent JPanel BorderFactory))
javax.swing.BorderFactory
user=> (JPanel. (.setBorder (.createTitledBorder "Title")))
#<CompilerException java.lang.IllegalArgumentException: No matching field found: createTitledBorder for class java.lang.String (NO_SOURCE_FILE:785)>

我在哪里可以找到处理这种情况的规则？一如既往，我们将非常感谢您的帮助。

我感谢大家的回答和澄清。我发布了该函数的基础知识，以便我们都知道该参考什么：

(import '(javax.swing JComponent JButton JFrame JLabel JPanel BorderFactory))
(use '(clojure.contrib [miglayout :only (miglayout)]))

(defn cm_dlg []
  (let
    [
     panel_0
     (miglayout
       (JPanel.)
       :layout  [:wrap 2]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       )
     panel_1
     (miglayout 
       (JPanel.)
       :layout  [:wrap]
       (JButton. "Button0") [:align "center"]
       (JButton. "Button1") [:align "center"]
       (JButton. "Button2") [:align "center"]
       (JButton. "Button3") [:align "center"]
       )
     frame (JFrame. "Frame")
     ]
    (doto frame
      (.setDefaultCloseOperation JFrame/DISPOSE_ON_CLOSE)
      (-> .getContentPane
        (.add (miglayout (JPanel.)
                :layout [:flowy]
                panel_0 [:align "center"]
                panel_1 [:align "center"]
                )))
      (.pack)
      (.setVisible true))))

就像该函数工作没有问题但我想做的是将 TitledBorder 放在 panel_0 上。按照您的指示，我尝试以不同的方式进行编码，但到目前为止尚未成功。
再次感谢大家的帮助。

更新：抱歉，googloplex。面对所有这些混乱，我正在运行不同的定义。是的，正如你和 Kugathasan 所说的那样。我最终编码为：

....
   (JButton. "Button3") [:align "center"]
   )
     tb (BorderFactory/createTitledBorder "Title")
     frame (JFrame. "Frame")
     ]
    (.setBorder panel_0 tb)
    (doto frame
....

并且成功了！！！感谢大家为此投入时间。

原文

Coming from LISP I am having my most challenging moments when accessing java objects. I am trying to put a titled border on a JPanel. Here is my code and exception:

user=> (import '(javax.swing JComponent JPanel BorderFactory))
javax.swing.BorderFactory
user=> (JPanel. (.setBorder (.createTitledBorder "Title")))
#<CompilerException java.lang.IllegalArgumentException: No matching field found: createTitledBorder for class java.lang.String (NO_SOURCE_FILE:785)>

Where can I find rules to deal with this kind of situations?
As always your help will be highly appreciated.

I thank you all for your answers and clarifications. I am posting the basics of the function so we can all know what to refer to:

(import '(javax.swing JComponent JButton JFrame JLabel JPanel BorderFactory))
(use '(clojure.contrib [miglayout :only (miglayout)]))

(defn cm_dlg []
  (let
    [
     panel_0
     (miglayout
       (JPanel.)
       :layout  [:wrap 2]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       (JLabel. "Some Text:") [:align "right"]
       (JLabel. "More Text:") [:align "left"]
       )
     panel_1
     (miglayout 
       (JPanel.)
       :layout  [:wrap]
       (JButton. "Button0") [:align "center"]
       (JButton. "Button1") [:align "center"]
       (JButton. "Button2") [:align "center"]
       (JButton. "Button3") [:align "center"]
       )
     frame (JFrame. "Frame")
     ]
    (doto frame
      (.setDefaultCloseOperation JFrame/DISPOSE_ON_CLOSE)
      (-> .getContentPane
        (.add (miglayout (JPanel.)
                :layout [:flowy]
                panel_0 [:align "center"]
                panel_1 [:align "center"]
                )))
      (.pack)
      (.setVisible true))))

Like that the function works no problem but what I am trying to do is to put a TitledBorder on panel_0. Following your instructions I have tried to code in different ways but not success so far.
Thanks again to you all for your help.

UPDATE:Sorry googloplex. With all this mess I was running a different defn.
Yes it works as you and Kugathasan said.
I finally coded as:

....
   (JButton. "Button3") [:align "center"]
   )
     tb (BorderFactory/createTitledBorder "Title")
     frame (JFrame. "Frame")
     ]
    (.setBorder panel_0 tb)
    (doto frame
....

and IT WORKED !!!
Thank you all for dedicating your time to this.

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酒浓于脸红 2024-12-27 03:21:17

你可以这样尝试，你在Clojure中访问Java的方式是错误的。

(.setBorder (JPanel.) (BorderFactory/createTitledBorder "Title"))

您可以阅读 java interop 参考资料来了解如何在 Clojure 中访问 Java。

You can try like this, the way you access Java in Clojure is wrong.

(.setBorder (JPanel.) (BorderFactory/createTitledBorder "Title"))

You may read java interop references to know how to access Java in Clojure..

回复收藏 0 原文

醉梦枕江山 2024-12-27 03:21:17

Clojure 语言参考此处很好地给出了 java 互操作性规则。
以下是要点：

静态方法的调用就像使用类名作为命名空间的普通函数一样：
```
(系统/getProperty“java.class.path”)
```
这将解析为 java 调用 System.getProperty("java.class.path")
常规方法是在类的特定对象上调用的，因此它们的调用语法略有不同：
```
(.setText 标签“一些文本”)
```
这将解析为 java 调用label.setText("Some text")。也就是说，常规方法调用采用以下形式：
```
(.methodName 对象 arg1 arg2 arg3 ...)
```
使用特殊形式构造对象new：
```
（新 JLabel“初始文本”）
```
有一个使用点读取器宏的简写：
```
(JLabel.“初始文本”)
```
最后两种形式是完全等价的。因此，如您所见，构造采用以下形式：
```
（新类名 arg1 arg2 ...）
;或者
(类名.arg1 arg2 ...)
```

当然，要使用常规方法，您必须将新创建的对象绑定到某个符号，例如：

(let [label (JLabel. "Initial text")]
  ...)

在 let 主体中，您现在可以使用 label 作为对象：

(let [label (JLabel. "Initial text")]
  (.setText label "New text")
  (.setIconTextGap label 10))

正如 Kugathasan Abimaran 答案的评论中的代码所示，您尝试在多个地方使用相同的 JPanel。你这样做是错误的，因为（参见上面的#3）(JPanel. ...)是一种构造形式，每次使用它时它都会返回新对象。您必须将新对象绑定到某个变量，然后调用它的方法，然后将其放入容器/任何您需要的东西中。

更新：
你的代码很好，你应该像 Kugathasan Abimaran 建议的那样做。在您的 (doto frame ... 行之前添加他的代码，将其中的 (JPanel.) 替换为您的 panel_0。它将按要求工作。

Clojure language reference here gives the java interoperability rules pretty well.
Here are the main points:

Static methods are called just like plain functions using class name as namespace:
```
(System/getProperty "java.class.path")
```
This will be resolved to java call System.getProperty("java.class.path")
Regular methods are called on specific objects of the class, so their calling syntax is slightly different:
```
(.setText label "Some text")
```
This will be resolved to java call label.setText("Some text"). That is, the regular method calls take this form:
```
(.methodName object arg1 arg2 arg3 ...)
```
Object are constructed using special form new:
```
(new JLabel "Initial text")
```
There is a shorthand for it using dot reader macro:
```
(JLabel. "Initial text")
```
These last two forms are completely equivalent. So, as you can see, construction takes this form:
```
(new Classname arg1 arg2 ...)
; or
(Classname. arg1 arg2 ...)
```

Of course, to use regular methods you have to bind newly created object to some symbol, e.g. like this:

(let [label (JLabel. "Initial text")]
  ...)

Inside let body you now can use label as an object:

(let [label (JLabel. "Initial text")]
  (.setText label "New text")
  (.setIconTextGap label 10))

As follows from your code in the commentary to Kugathasan Abimaran's answer, you are trying to use the same JPanel in several places. You are doing it incorrectly, since (see #3 above) (JPanel. ...) is a construction form, it returns new object every time you use it. You have to bind the new object to some variable, then call methods on it and then put it into container/whatever you need.

UPDATE:
Your code is fine, you should do like Kugathasan Abimaran suggested. Add his code just before your (doto frame ... line, replacing (JPanel.) there with your panel_0. It will work as required.