Ich baue eine Android-App, bei der ich die Sichtbarkeit einiger Ansichtselemente basierend auf einem Knopfklick umschalten möchte. Ich versuche, es mit Datenbindung statt findViewById() zu archivieren, aber alle Lösungen, die ich bis jetzt gefunden habe, aktualisiert das Layout nicht, wenn die Variable geändert wird.Dynamische Umschaltung der Sichtbarkeit von Layoutelementen mit Android-Datenbindung.
Hier ist was ich bisher habe. (Ich habe den Code vereinfacht, auf das Problem zu konzentrieren)
Activicy.java
public class RecipeActivity extends AppCompatActivity {
private Recipe recipe;
private ActivityRecipeBinding binding;
private RecipeBinderHelper rbhelper = new RecipeBinderHelper();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent = getIntent();
recipe = intent.getParcelableExtra("recipe");
binding = DataBindingUtil.setContentView(this, R.layout.activity_recipe);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle(recipe.getName());
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
binding.recipeContent.setRecipe(recipe);
binding.recipeContent.setHelper(rbhelper);
binding.Button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//HERE I CHANGE THE VALUE OF THE VARIBLE
rbhelper.setPresentationViewVisible(false);
binding.notifyChange();
}
});
}
}
Helper Klasse
public class RecipeBinderHelper{
private Boolean presentationElementsVisible;
private Boolean timerElementsVisible;
public RecipeBinderHelper(){
this.presentationElementsVisible = true;
this.timerElementsVisible = false;
}
public void setPresentationViewVisible(boolean presentationElementsVisible) {
this.presentationElementsVisible = presentationElementsVisible;
}
public Boolean getPresentationElementsVisible() {
return presentationElementsVisible;
}
//getters and setters for private Boolean timerElementsVisible;
}
Layout-
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<import type="android.view.View"/>
<variable
name="helper"
type="com.myapps.recipeApp.RecipeBinderHelper"/>
<variable
name="recipe"
type="com.myapps.recipeApp.Recipe"/>
</data>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.myapp.recipeApp.RecipeActivity"
tools:showIn="@layout/activity_recipe">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/r_source"
android:textStyle="bold"
android:text="@{recipe.source}"
android:visibility="@{helper.presentationElementsVisible ? View.VISIBLE : View.GONE}" />
<!-- More TextViews here -->
<!-- Button is located in parret layout -->
</RelativeLayout>
</layout>