创建一个窗口，在窗口中间放置一个按键，当按键发生鼠标点击事件，打开文件选择器。如果用户选择了某一个文件，并点击“打开”，在控制台输出该文件的绝对路径。
1 import java.io.File; 2 3 import javafx.application.Application; 4 import javafx.event.ActionEvent; 5 import javafx.event.EventHandler; 6 import javafx.geometry.Insets; 7 import javafx.geometry.Pos; 8 import javafx.scene.Scene; 9 import javafx.scene.control.Button; 10 import javafx.scene.layout.GridPane; 11 import javafx.stage.FileChooser; 12 import javafx.stage.FileChooser.ExtensionFilter; 13 import javafx.stage.Stage; 14 15 public class Main extends Application { 16 17 public static void main(String[] args) { 18 launch(args); 19 } 20 21 @Override 22 public void start(Stage primaryStage) throws Exception { 23 // Create a pane to hold a button 24 GridPane pane = new GridPane(); 25 pane.setStyle("-fx-border-color: green;"); 26 pane.setAlignment(Pos.CENTER); 27 pane.setPadding(new Insets(10, 10, 10, 10)); 28 pane.setHgap(10); 29 pane.setVgap(10); 30 31 // Create a button 32 Button btOpen = new Button("Open"); 33 pane.add(btOpen, 0, 0); 34 35 // Set the primary stage properties 36 primaryStage.setScene(new Scene(pane, 400, 200)); 37 primaryStage.setTitle("Starting..."); 38 primaryStage.setResizable(false); 39 primaryStage.show(); 40 41 btOpen.setOnAction(new EventHandler<ActionEvent>() { 42 @Override 43 public void handle(ActionEvent event) { 44 FileChooser fileChooser = new FileChooser(); 45 fileChooser.setTitle("Open"); 46 // 第47~48行代码的作用等效于第49行代码的作用，用于设置扩展名过滤器。 47 // fileChooser.getExtensionFilters().add(new ExtensionFilter("Text Files", "*.txt")); 48 // fileChooser.getExtensionFilters().add(new ExtensionFilter("All Files", "*.*")); 49 fileChooser.getExtensionFilters().addAll(new ExtensionFilter("Text Files", "*.txt"), new ExtensionFilter("All Files", "*.*")); 50 File file = fileChooser.showOpenDialog(primaryStage); 51 if (file != null) { 52 System.out.println(file.getAbsolutePath()); 53 } 54 } 55 }); 56 } 57 }
控制台的输出：（有异常）
Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. Qt: Untested Windows version 10.0 detected! log4cplus:ERROR No appenders could be found for logger (AdSyncNamespace). log4cplus:ERROR Please initialize the log4cplus system properly. J:\PrtSc\20190321\Nobody.png
UI：
