目录

题目：*16.6 (演示TextField的属性)

习题思路

代码示例

 结果展示

---

题目：*16.6 (演示TextField的属性)

  编写一个程序，动态地设置文本域的水平对齐属性和列宽属性，如图16-38a所示

• 习题思路

1. 创建一个HBox，一个Label和一个TextField，
2. 再创建一个HBox，新建三个RadioButton，设置切换组，再创建另一个Label和TextField
3. 为三个单选按钮注册事件，当按钮被勾选时将HBox设置对应的对齐方式(HBox.setAlignment(Pos.***))
4. 为第二个TextField注册键盘事件，当在输入框内按下Enter键时，将TextField1的宽度设置为输入的数字

• 代码示例

编程练习题16_6TextFieldPropertyDemo.java

package chapter_16;

import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.RadioButton;
import javafx.scene.control.TextField;
import javafx.scene.control.ToggleGroup;
import javafx.scene.input.KeyCode;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class 编程练习题16_6TextFieldPropertyDemo extends Application{
	@Override
	public void start(Stage primaryStage) throws Exception {
		HBox hBox1 = new HBox(20);
		hBox1.setAlignment(Pos.CENTER);
		Label lbText = new Label("Text Field");
		TextField tfText = new TextField();
		hBox1.getChildren().addAll(lbText, tfText);
		
		HBox hBox2 = new HBox(10);
		hBox2.setAlignment(Pos.CENTER);
		RadioButton rbLeft = new RadioButton("Left");
		RadioButton rbCenter = new RadioButton("Center");
		RadioButton rbRight = new RadioButton("Right");
		ToggleGroup group = new ToggleGroup();
		rbLeft.setToggleGroup(group);
		rbCenter.setToggleGroup(group);
		rbRight.setToggleGroup(group);
		Label lbSize = new Label("Column Size");
		TextField tfSize = new TextField();
		hBox2.getChildren().addAll(rbLeft, rbCenter, rbRight,lbSize, tfSize);
		
		rbLeft.setOnAction(e ->{
			if(rbLeft.isSelected()) {
				hBox1.setAlignment(Pos.TOP_LEFT);
			}
		});
		rbCenter.setOnAction(e ->{
			if(rbCenter.isSelected()) {
				hBox1.setAlignment(Pos.TOP_CENTER);
			}
		});
		rbRight.setOnAction(e ->{
			if(rbRight.isSelected()) {
				hBox1.setAlignment(Pos.TOP_RIGHT);
			}
		});
		
		tfSize.setOnKeyPressed(e ->{
			if(e.getCode() == KeyCode.ENTER) {
				tfText.setPrefWidth(Integer.parseInt(tfSize.getText()));
			}
		});
		
		BorderPane borderPane = new BorderPane();
		borderPane.setTop(hBox1);
		borderPane.setCenter(hBox2);
		
		Scene scene = new Scene(borderPane,450, 100);
		primaryStage.setTitle("编程练习题16_6TextFieldPropertyDemo");
		primaryStage.setScene(scene);
		primaryStage.show();
	}
	public static void main(String[] args) {
		Application.launch(args);
	}
}

•  结果展示