Android新手开发之旅-Gallery和ImageSwitcher的用法

liu

Gallery可以使内部元素水平滚动并将选择的子元素设置在中间位置，一般用来浏览图片


ImageSwitcher可以显示图片，主要用于多张图片的切换显示


用法都比较简单，下面使用Gallery+ImageSwitcher来实现一个简单的图片浏览器


activity_main.xml:

[XML] 纯文本查看 复制代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/black"
    android:orientation="vertical"
    android:padding="20dp">

    <Gallery
        android:id="@+id/gl"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <ImageSwitcher
        android:id="@+id/is"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp" />
</LinearLayout>

MyAdapter:

[Java] 纯文本查看 复制代码

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

/**
 * Created by Administrator on 2019/1/4.
 */

public class MyAdapter extends BaseAdapter {
    private Context context;
    private int[] imgList;

    public MyAdapter(Context context, int[] imgList) {
        this.context = context;
        this.imgList = imgList;
    }

    //返回Integer.MAX_VALUE是为了图片可以无限循环
    @Override
    public int getCount() {
        return Integer.MAX_VALUE;
    }

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView = new ImageView(context);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);
        imageView.setImageResource(imgList[position % imgList.length]);
        imageView.setLayoutParams(new Gallery.LayoutParams(300, 200));
        return imageView;
    }
}

MainActivity:

[Java] 纯文本查看 复制代码

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher;

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener, ViewSwitcher.ViewFactory {
    private int[] imgs = {R.drawable.img1, R.drawable.img2, R.drawable.img3, R.drawable.img4, R.drawable.img5, R.drawable.img6};
    private Gallery mGallery;
    private ImageSwitcher mImageSwitcher;

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

        initView();
    }

    private void initView() {
        mGallery = (Gallery) findViewById(R.id.gl);
        mImageSwitcher = (ImageSwitcher) findViewById(R.id.is);
        MyAdapter adapter = new MyAdapter(this, imgs);
        mGallery.setAdapter(adapter);

        mGallery.setOnItemSelectedListener(this);
        mImageSwitcher.setFactory(this);

        //添加动画
        mImageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, R.anim.alpha_in));
        mImageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, R.anim.alpha_out));
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        mImageSwitcher.setImageResource(imgs[position % imgs.length]);
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }

    @Override
    public View makeView() {
        ImageView imageView = new ImageView(this);
        imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
        return imageView;
    }
}

alpha_in.xml:

[XML] 纯文本查看 复制代码

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <alpha
        android:duration="1000"
        android:fromAlpha="0.1"
        android:toAlpha="1.0" />
</set>

alpha_out.xml:

[XML] 纯文本查看 复制代码

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <alpha
        android:duration="1000"
        android:fromAlpha="1.0"
        android:toAlpha="0.1" />
</set>

效果图：
        

站长苏飞

我只是路过打酱油的。

Amy

强烈支持楼主ing……

范范

我只是路过打酱油的。

竹林风

强烈支持楼主ing……

惜

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