Question

我有一个带有Textfield1和Button的View1。当我单击一个按钮时，我想转到视图2并在View2中将该值设置为Textfield2。当我做它时，它会打开一个新的场景。

这是传递值的代码：

charmListView.selectedItemProperty().addListener((obs, oldSelection,    
newSelection) -> {
        if (newSelection != null) {
            ModellList l = new ModellList();
            charmListView.selectedItemProperty().get().getName();
               l.setName(charmListView.selectedItemProperty()
  .get().getName());
            SucheFahrtPresenter s = new SucheFahrtPresenter();

              MobileApplication.getInstance()
.switchView(SUCHEFAHRT_VIEW);
s.setDP(l.getName());


        }
    });

我有这个错误：

 Exception in thread "JavaFX Application Thread"        
 java.lang.NullPointerException

 at com.gluonapplication.views.SucheFahrtPresenter.setDP(SucheFahrtPresenter.java:122)
at com.gluonapplication.views.BasicView$3.lambda$run$0(BasicView.java:119)
at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.ObjectPropertyBase.fireValueChangedEvent(ObjectPropertyBase.java:105)
at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
at com.gluonhq.charm.glisten.control.CharmListView.setSelectedItem(SourceFile:710)

我尝试了第二种解决方案：

那是第二位主持人：

import javax.inject.Inject;

@Inject
private Model model; 

public void initialize() {
         ........
    second.showingProperty().addListener((obs, oldValue, newValue) -> {
        if (newValue) {
            DP.setText(model.getText());
        }
    });
}

这是第一位主持人：

import javax.inject.Inject;

@Inject
private Model model;

@FXML
public void test() {
    charmListView.selectedItemProperty().
    addListener((obs, oldSelection, newSelection) -> {
        if (newSelection != null) {
            ModellList l = new ModellList();
            charmListView.selectedItemProperty().get().getName();
            l.setName(charmListView.selectedItemProperty().
    get().getName());
            SucheFahrtPresenter s = new SucheFahrtPresenter();
            model.setText(l.getName());
            MobileApplication.getInstance().switchView(SUCHEFAHRT_VIEW);

        }
    });
}

这些是我在Gradle中的依赖项：

dependencies {
    compile 'com.gluonhq:charm:4.2.0'
    compile group: 'org.controlsfx', name: 'controlsfx', version: '8.40.12'
    compile  'de.jensd:fontawesomefx:8.9'
    androidRuntime 'org.sqldroid:sqldroid:1.0.3'
    androidCompile 'org.glassfish:javax.json:1.0.4'
    compile group: 'org.xerial', name: 'sqlite-jdbc', version: '3.15.1'
    compile group: 'org.sqldroid', name: 'sqldroid', version: '1.0.3'   
    compile group: 'com.gluonhq', name: 'charm-down-desktop', version:    
   '0.0.2'
    compile group: 'com.gluonhq', name: 'charm-down-common', version: 
  '0.0.1'
    compile group: 'com.gluonhq', name: 'charm-down-android', version:  
  '0.0.1'
    compile group: 'com.airhacks', name: 'afterburner.fx', version: '1.7.0'   
 }

这是我的问题：

更改Charmlistview的代码后。我有这个错误

线程中的异常＆＃34; JavaFX应用程序线程＆＃34;显示java.lang.NullPointerException at com.gluonapplication.views.SucheFahrtPresenter.lambda $ setDP $ 4（SucheFahrtPresenter.java:138） at com.sun.javafx.binding.ExpressionHelper $ Generic.fireValueChangedEvent（ExpressionHelper.java:361） at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent（ExpressionHelper.java:81）在javafx.beans.property.ReadOnlyBooleanPropertyBase.fireValueChangedEvent（ReadOnlyBooleanPropertyBase.java:72）在javafx.beans.property.ReadOnlyBooleanWrapper.fireValueChangedEvent（ReadOnlyBooleanWrapper.java:103）在javafx.beans.property.BooleanPropertyBase.markInvalid（BooleanPropertyBase.java:110）在javafx.beans.property.BooleanPropertyBase.set（BooleanPropertyBase.java:144）在com.gluonhq.charm.glisten.mvc.View.c（SourceFile：1158）

Answer 1

我建议您使用Gluon模板Project MultiView与FXML和Afterburner，或Glisten-Afterburner。它们中的任何一个都允许您使用注入并获得演示者的有效实例。

解决方案1. Glisten-Afterburner

使用Glisten-Afterburner默认模板，我添加了两个TextField控件，每个控件都有一个。

您唯一需要的是暴露一个方法来设置第二个演示者的值：

slugurl

在第一个视图中，您可以在按钮事件处理程序中切换视图并设置文本：

public class SecondaryPresenter extends GluonPresenter<YourApp> {

    @FXML
    private View secondary;

    @FXML
    private TextField textField;

    public void initialize() {
        ...
    }

    public void setText(String value) {
        textField.setText(value);
    }
}

此解决方案需要Gluon IDE插件2.5.0

解决方案2. MultiView

或者，您可以将MultiView与FXML和Afterburner模板一起使用，并创建一个Model类：

public class PrimaryPresenter extends GluonPresenter<YourApp> {

    @FXML
    private View primary;

    @FXML
    private CharmListView<String, String> charmListView;

    public void initialize() {
        charmListView.setItems(FXCollections.observableArrayList("One", "Two", "Three", "Four"));
        charmListView.selectedItemProperty().addListener((obs, ov, nv) -> {
            AppViewManager.SECONDARY_VIEW.switchView()
                .ifPresent(presenter -> 
            ((SecondaryPresenter) presenter).setText(nv));
        });
        ...
    }

}

您可以在两位演示者中注入：

public class Model {

    private final StringProperty text = new SimpleStringProperty();
    public final void setText(String value) { text.set(value); }
    public final String getText() { return text.get(); }
    public final StringProperty textProperty() { return text; }

}

和

public class PrimaryPresenter {

    @FXML
    private View primary;

    @FXML
    private CharmListView<String, String> charmListView;

    @Inject
    private Model model;

    public void initialize() {
        charmListView.setItems(FXCollections.observableArrayList("One", "Two", "Three", "Four"));
        charmListView.selectedItemProperty().addListener((obs, ov, nv) -> {
            model.setText(nv);
            MobileApplication.getInstance().switchView(SECONDARY_VIEW);
        });
        ...
    }
}

如何在gluon mobile中将数据从一个视图传递到另一个视图？如何切换到查看和设置值？

1 个答案: