Die Anleitung zu Android ImageSwitcher
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Das ist das Foto einer Applikation, die ImageSwitcher benutzen:

- TODO: More infos
Erstellen Sie ein Project mit dem Name von AndroidImageSwitcher:
- File > New Project > Empty Activity


Sie brauchen einige Fotos zur Teilnahme an dem Beispiel
image1.png | |
image2.png | |
image3.png |
Kopieren Sie die oben Fotos in dem Ordner drawable.



Das Interface der Applikation

Wenn Sie an den Schritten zum Entwerfen der Benutzerinterface dieser Anwendung interessiert sind, lesen Sie bitte den Anhang am Ende des Artikels.
main_actvity.xml
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <ImageSwitcher android:id="@+id/imageSwitcher" android:layout_width="0dp" android:layout_height="279dp" android:layout_marginStart="16dp" android:layout_marginLeft="16dp" android:layout_marginTop="27dp" android:layout_marginEnd="16dp" android:layout_marginRight="16dp" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="16dp" android:layout_marginLeft="16dp" android:layout_marginTop="16dp" android:layout_marginEnd="16dp" android:layout_marginRight="16dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/imageSwitcher"> <Space android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" /> <Button android:id="@+id/button_previous " android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="0" android:text="Previous" /> <Button android:id="@+id/button_next" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="0" android:text="Next" /> <Space android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" /> </LinearLayout> </androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
package org.o7planning.androidimageswitcher; import android.os.Bundle; import android.app.ActionBar.LayoutParams; import android.graphics.Color; import android.util.Log; import android.view.View; import android.view.animation.Animation; import android.view.animation.AnimationUtils; import android.widget.Button; import android.widget.ImageSwitcher; import android.widget.ImageView; import android.widget.Toast; import android.widget.ViewSwitcher.ViewFactory; import androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { private ImageSwitcher imageSwitcher; private Button buttonPrevious; private Button buttonNext; private final String[] imageNames={"image1", "image2", "image3"}; private int currentIndex; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); buttonPrevious = (Button) findViewById(R.id.button_previous); buttonNext = (Button) findViewById(R.id.button_next); imageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher); // Animation when switching to another image. Animation out= AnimationUtils.loadAnimation(this, android.R.anim.fade_out); Animation in= AnimationUtils.loadAnimation(this, android.R.anim.fade_in); // Set animation when switching images. imageSwitcher.setInAnimation(in); imageSwitcher.setOutAnimation(out); // imageSwitcher.setFactory(new ViewFactory() { // Returns the view to show Image // (Usually should use ImageView) @Override public View makeView() { ImageView imageView = new ImageView(getApplicationContext()); imageView.setBackgroundColor(Color.LTGRAY); imageView.setScaleType(ImageView.ScaleType.CENTER); ImageSwitcher.LayoutParams params= new ImageSwitcher.LayoutParams( LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); imageView.setLayoutParams(params); return imageView; } }); this.currentIndex=0; this.showImage(this.currentIndex); buttonPrevious.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { previousImage(); } }); buttonNext.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { nextImage(); } }); } private void previousImage() { if(currentIndex > 0) { currentIndex--; }else { Toast.makeText(getApplicationContext(), "No Previous Image", Toast.LENGTH_SHORT).show(); return; } this.showImage(currentIndex); } private void nextImage() { if(currentIndex < this.imageNames.length-1) { currentIndex++; }else { Toast.makeText(getApplicationContext(), "No Next Image", Toast.LENGTH_SHORT).show(); return; } this.showImage(currentIndex); } private void showImage(int imgIndex) { String imageName= this.imageNames[imgIndex]; int resId= getDrawableResIdByName(imageName); if(resId!= 0) { this.imageSwitcher.setImageResource(resId); } } // Find Image ID corresponding to the name of the image (in the drawable folder). public int getDrawableResIdByName(String resName) { String pkgName = this.getPackageName(); // Return 0 if not found. int resID = this.getResources().getIdentifier(resName , "drawable", pkgName); Log.i("MyLog", "Res Name: " + resName + "==> Res ID = " + resID); return resID; } }
Starten Sie die Applikation:

Ich weiß nicht, warum ImageSwitcher im Entwurfsfenster von Android Studio 3.6.x nicht verfügbar ist, sodass Sie es nicht in die Interface ziehen können. Der beste Weg ist, den folgenden XML-Code zur Datei activity_main.xml hinzuzufügen, und Sie erhalten ImageSwitcher auf der Interface.
<ImageSwitcher android:layout_width="100dp" android:layout_height="100dp" />


Legen Sie ID, Text für die Komponenten in die Interface fest.
