如何在 JavaFX 中设置 ComboBox 的下拉宽度? [英] How to set width of drop down of ComboBox in JavaFX?

问题描述

我的 ComboBox 的下拉列表扩展到其中输入的最大元素的大小.但是我希望它是固定大小.

The drop down list of my ComboBox expands to the size of the largest element entered in it. However I want it to be a fixed size.

---------------------
| Small Combobox | V |
--------------------------------------------
| "Long item 1"                              |
--------------------------------------------
| "Long item 2"                              |
 --------------------------------------------
| "Long item 3"                              |
 --------------------------------------------

推荐答案

使用 CSS

/** file: combo-size.css */

/** Size the combo-box button. */
.combo-box {
    -fx-pref-width: 100;
}

/** Size the combo-box drop down list. */
.combo-box-popup > .list-view {
    -fx-pref-width: 100;
}

注意:我仅在 Java 8 上测试了这个示例，我相信 -fx-*-width 和 -fx-*-height css 属性可能是 JavaFX 8 的新功能.

Note: I tested this sample only on Java 8 and I believe the -fx-*-width and -fx-*-height css attributes may be new for JavaFX 8.

示例用法

在此示例中，组合框按钮和下拉列表的大小都设置为相同的首选宽度(100 像素).

In this sample, both the combo box button and the drop down list have been sized to the same preferred width (of 100 pixels).

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.layout.StackPane;
import javafx.scene.text.Font;
import javafx.stage.Stage;

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

    @Override public void start(Stage stage) {
        final ComboBox<String> combo = new ComboBox<>();

        combo.setValue(Font.getDefault().getFamily());
        combo.getItems().setAll(Font.getFamilies());
        combo.getStylesheets().add(
                getClass().getResource(
                        "combo-size.css"
                ).toExternalForm()
        );

        StackPane layout = new StackPane(combo);
        layout.setPadding(new Insets(10));

        stage.setScene(new Scene(layout));
        stage.show();
    }
}

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