问题

我在基于JDK 8和JavaFX的桌面应用程序上工作。

我创建了一个自定义对话框类，其中包含2个按钮（完成和取消）。我的目标是在对话框中点击“完成”按钮后返回添加在对话框中的字符串列表（取消操作会返回空列表）。

我遇到了问题，因为showAndWait函数返回我点击的按钮类型（'ButtonType.FINISH'或'ButtonType.CANCEL'）。我的目标是覆盖完成和关闭按钮上的默认操作，我希望返回字符串列表而不是按钮类型。

虽然始终可以创建自定义按钮，但最好使用JavaFX已提供的按钮。

作为响应，您可以使用任何JVM语言（Java/Kotlin/Scala）。

代码：
```kotlin
class MyDialog : Dialog<MutableList<String>>() {
  val listToReturn: MutableList<String> = mutableListOf()
    
  init {
    val dialogPane: DialogPane = this.dialogPane

    dialogPane.buttonTypes.addAll(ButtonType.FINISH, ButtonType.CANCEL)
  }
}

val myDialog: MyDialog = MyDialog()

// 这里我得到的是ButtonType（'ButtonType.FINISH'或'ButtonType.CANCEL'），而不是字符串列表
myDialog.showAndWait().ifPresent { list -> println(list) }

<details>
<summary>英文:</summary>

I work on desktop application based on JDK 8 and JavaFX.

I created custom dialog class with 2 buttons(finish and cancel). My goal is to return the list of strings added in dialog (after clicking finish button, dialog returns list. Cancel makes return empty list).

I have problem, beacause function showAndWait return type of button which I clicked (&#39;ButtonType.FINISH&#39; or &#39;ButtonType.CANCEL&#39;). My goal is to override default action on finish and close button and I want to return list instead of return button type.

It&#39;s always possible to create custom buttons, however, it would be better to use those already provided by JavaFX.

In response, you can use any of the JVM languages (Java/Kotlin/Scala).

Code:

class MyDialog : Dialog<MutableList<String>>() {
val listToReturn: MutableList<String> = mutableListOf()

init {
val dialogPane: DialogPane = this.dialogPane

dialogPane.buttonTypes.addAll(ButtonType.FINISH, ButtonType.CANCEL)

}
}

val myDialog: MyDialog = MyDialog()

// here I got ButtonType ('ButtonType.FINISH' or 'ButtonType.CANCEL'), not list of string
myDialog.showAndWait().ifPresent { list -> println(list) }

</details>


# 答案1
**得分**: 2

你需要使用一个结果转换器

```java
public class MyDialog extends Dialog<List<String>> {
    ArrayList<String> returnList = new ArrayList<>();
    public MyDialog() {
        returnList.add("test 1");
        returnList.add("test 2");
        this.getDialogPane().getButtonTypes().addAll(ButtonType.FINISH, ButtonType.CANCEL);

        setResultConverter(dialogButton -> {
           if (dialogButton == ButtonType.FINISH) {
               return returnList;
           }
           return new ArrayList<>();
        });
    }
}

对于应用程序端

public class Main extends Application {
    public static void main(String[] args) {
        launch();
    }

    @Override
    public void start(Stage primaryStage) {
        MyDialog myDialog = new MyDialog();
        myDialog.showAndWait().ifPresent(System.out::println);
    }
}

public class MyDialog extends Dialog<List<String>> {
    ArrayList<String> returnList = new ArrayList<>();
    public MyDialog() {
        returnList.add("test 1");
        returnList.add("test 2");
        this.getDialogPane().getButtonTypes().addAll(ButtonType.FINISH, ButtonType.CANCEL);

        setResultConverter(dialogButton -> {
           if (dialogButton == ButtonType.FINISH) {
               return returnList;
           }
           return new ArrayList<>();
        });
    }
}

public class main extends Application {
    public static void main (String [] args) {
        launch();
    }

    @Override
    public void start(Stage primaryStage) {
        MyDialog myDialog = new MyDialog();
        myDialog.showAndWait().ifPresent(System.out::println);
    }
}