Android 图片画廊效果示例代码 - 简单实现图片展示

以下是一个示例代码，实现了一个简单的Android图片画廊效果：

activity_main.xml 布局文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    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"
    tools:context=".MainActivity">

    <Gallery
        android:id="@+id/gallery"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:spacing="10dp" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/gallery"
        android:scaleType="centerCrop" />

</RelativeLayout>

MainActivity.java 代码：

import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Gallery;
import android.widget.ImageView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private Gallery gallery;
    private ImageView imageView;

    private int[] images = {
            R.drawable.image1,
            R.drawable.image2,
            R.drawable.image3,
            R.drawable.image4,
            R.drawable.image5
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        gallery = findViewById(R.id.gallery);
        imageView = findViewById(R.id.imageView);

        ImageAdapter imageAdapter = new ImageAdapter(this, images);
        gallery.setAdapter(imageAdapter);

        gallery.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                imageView.setImageResource(images[position]);
            }
        });
    }
}

ImageAdapter.java 代码：

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;

public class ImageAdapter extends BaseAdapter {

    private Context context;
    private int[] images;

    public ImageAdapter(Context context, int[] images) {
        this.context = context;
        this.images = images;
    }

    @Override
    public int getCount() {
        return images.length;
    }

    @Override
    public Object getItem(int position) {
        return images[position];
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {
            imageView = new ImageView(context);
            imageView.setLayoutParams(new Gallery.LayoutParams(200, 200));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        } else {
            imageView = (ImageView) convertView;
        }
        imageView.setImageResource(images[position]);
        return imageView;
    }
}

以上代码实现了一个简单的图片画廊效果。在MainActivity中，将图片资源数组设置给ImageAdapter，并将ImageAdapter设置给Gallery，当用户点击画廊中的图片时，将对应的图片显示在ImageView中。