java - ImageView 不显示图像 - JavaFX

Question

这个问题已经有答案了:

Javafx 8 : Populating a TableView in initialize method (1 个回答)

已关闭 3 年前。

我在 Java fx Controller 类中有一些代码，如下所示。图像没有显示。图片到位，没有错误。请指导。

@Override
public void initialize(URL location, ResourceBundle resources) {
    image1 = new Image(getClass().getResource("php81e3DF.png").toExternalForm());
    image2 = new Image(getClass().getResource("phpqJypee.png").toExternalForm());
    image3 = new Image(getClass().getResource("php2XSnrZ.png").toExternalForm());
    defaultt = new Image(getClass().getResource("phpxrxh4T.png").toExternalForm());

    imgVw1 = new ImageView();
    imgVw1.setX(200);
    imgVw1.setY(200);
    imgVw2 = new ImageView();
    imgVw3 = new ImageView();

    imgVw1.setImage(image1);
    imgVw2.setImage(image2);
    imgVw3.setImage(image3);
}

我无法显示图像。我确信 fxml 和 Controller 类正在使用正确的注释。我在类中使用了正确的@fxml，并且变量没有错误。

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>

<GridPane fx:id="rootPane" alignment="TOP_CENTER" hgap="10" vgap="10" xmlns="http://javafx.com/javafx/8.0.172-ea" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
   <children>
      <GridPane hgap="2.0" vgap="2.0">
        <columnConstraints>
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
            <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        </columnConstraints>
        <rowConstraints>
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
            <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
        </rowConstraints>
         <GridPane.margin>
            <Insets bottom="5.0" left="5.0" right="5.0" top="5.0" />
         </GridPane.margin>
         <children>
            <ImageView fx:id="imgVw1" fitHeight="150.0" fitWidth="200.0" pickOnBounds="true" preserveRatio="true" />
            <ImageView fx:id="imgVw2" fitHeight="150.0" fitWidth="200.0" pickOnBounds="true" preserveRatio="true" GridPane.columnIndex="1" />
            <ImageView fx:id="imgVw3" fitHeight="150.0" fitWidth="200.0" pickOnBounds="true" preserveRatio="true" GridPane.columnIndex="2" />
            <Button fx:id="imageV1Button" mnemonicParsing="false" onAction="#button1Pressed" text="Flip" GridPane.halignment="CENTER" GridPane.rowIndex="1" GridPane.valignment="CENTER" />
            <Button fx:id="imageV2Button" mnemonicParsing="false" onAction="#button1Pressed" text="Flip" GridPane.columnIndex="1" GridPane.halignment="CENTER" GridPane.rowIndex="1" GridPane.valignment="CENTER" />
            <Button fx:id="imageV3Button" mnemonicParsing="false" onAction="#button1Pressed" text="Flip" GridPane.columnIndex="2" GridPane.halignment="CENTER" GridPane.rowIndex="1" GridPane.valignment="TOP" />
         </children>
      </GridPane>
   </children>
   <columnConstraints>
      <ColumnConstraints />
   </columnConstraints>
   <rowConstraints>
      <RowConstraints />
   </rowConstraints>
</GridPane>

Answer 1

您不必添加这些代码行:

imgVw1 = new ImageView();
imgVw2 = new ImageView();
imgVw3 = new ImageView();

当你这样做时会发生什么:

1. FXMLLoader 读取您的 FXML 文件以初始化整个 GridPane:imgVw1、imgVw2 和 imgVw3创建并添加到 rootPane 的子列表中。

2. 您为 imgVw1、imgVw2 和 imgVw3 定义新值，这意味着它们不再等于已定义的值到 FXML 中。因此，重新分配会自动使您的组件从 rootPane 的子列表中消失，并且不会显示任何 ImageView。

删除这 3 行应该可以解决你的问题(至少对我有用 ☻)。