画廊视图(Gallery)的功能和用法
Gallery与Spinner组件有共同的父类：AbsSpinner，表明Gallery和Spinner都是一个列表框。它们之间的区别在于Spinner显示的是一个垂直的列表选择框吗，而Gallery显示的是一个水平的列表选择框。下面以一个例子来说明：
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ImageView
android:id="@+id/imageView"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="1"/>
<Gallery
android:id="@+id/gallery"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="25dip"
android:unselectedAlpha="0.6"
android:spacing="2pt"/>
</LinearLayout>
MainActivity.java
package com.example.testgallary;
import android.app.Activity;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
public class MainActivity extends Activity {
private int[] imageIds = new int[]{
R.drawable.img1, R.drawable.img2,
R.drawable.img3, R.drawable.img4,
R.drawable.img5, R.drawable.img6,
};
private Gallery gallery;
private ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gallery = (Gallery) findViewById(R.id.gallery);
imageView = (ImageView) findViewById(R.id.imageView);
BaseAdapter adapter = new BaseAdapter() {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// 创建一个ImageView
ImageView imageView = new ImageView(MainActivity.this);
imageView.setImageResource(imageIds[position]);
// 设置ImageView的缩放类型
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
// 为imageView设置布局参数
imageView.setLayoutParams(new Gallery.LayoutParams(75, 100));
TypedArray typedArray = obtainStyledAttributes(
R.styleable.Gallery);
imageView.setBackgroundResource(typedArray.getResourceId(
R.styleable.Gallery_android_galleryItemBackground, 0));
return imageView;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public Object getItem(int item) {
// TODO Auto-generated method stub
return item;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return imageIds.length;
}
};
gallery.setAdapter(adapter);
gallery.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
imageView.setImageResource(imageIds[position]);
}
@Override
public void onNothingSelected(AdapterView<?> view) {
}
});
}
}
运行结果：
补充：web前端 , HTML/CSS ,
