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android开发步步为营之35:GridView的用法
之前使用asp.net开发软件的过程中也使用GridView,发现android里面也有这么一个控件,使用方法有点相似,都是使用适配器将数据绑定到这个控件,然后将数据展示出来,应该说它和ListView一样,是个非常常用的控件,所以我们应该学习如何使用它,理论知识是没多少的,就是一个展示数据的控件,继承关系如下:
public class GridView
extends AbsListView
java.lang.Object
android.view.View
android.view.ViewGroup
android.widget.AdapterView<T extends android.widget.Adapter>
android.widget.AbsListView
android.widget.GridView
开始我们的范例:
本范例,我们要实现两种效果:
第一种显示小狗的图片列表,点击图片后触发一个提示消息
第二种显示水浒梁山好汉的头像、姓名、年龄信息,点击一行后会在title显示姓名
第一步、设计页面
res\layout\gridview.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<GridView android:id="@+id/mygridview" android:layout_width="fill_parent"
android:layout_height="fill_parent" android:columnWidth="90dp"
android:numColumns="auto_fit" android:horizontalSpacing="10dp"
android:verticalSpacing="10dp" android:stretchMode="columnWidth"
android:gravity="center">
</GridView>
</RelativeLayout>
res\layout\personview.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView android:id="@+id/imgHead" android:layout_width="wrap_content" android:src=http://www.mamicode.com/"@drawable/icon" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_alignParentLeft="true">
<TextView android:id="@+id/tvName" android:text="姓名" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignBottom="@+id/imgHead" android:layout_toRightOf="@+id/imgHead" android:layout_marginLeft="40dp" android:layout_marginBottom="14dp"></TextView>
<TextView android:id="@+id/tvAge" android:text="年龄" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignTop="@+id/tvName" android:layout_toRightOf="@+id/tvName" android:layout_marginLeft="68dp"></TextView>
</RelativeLayout>
第二步、设计Activity GridViewActivity.java
/**
* gridview的用法
*/
package com.figo.helloworld;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
/**
* @author zhuzhifei
*
*/
public class GridViewActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gridview);
//给gv装配数据
GridView gridView = (GridView) findViewById(R.id.mygridview);
//使用系统视图ImageView
// gridView.setAdapter(new ImageAdapter(this));
// gridView.setColumnWidth(90);
// // 添加点击行事件
// gridView.setOnItemClickListener(new OnItemClickListener() {
// @Override
// public void onItemClick(AdapterView parent, View view,
// int position, long id) {
// Toast.makeText(GridViewActivity.this, "dog"+id+"汪汪汪",
// Toast.LENGTH_SHORT).show();
//
// }
// });
//使用简单适配器显示图片+文字
SimpleAdapter adapter = getSimpleAdapter();
gridView.setAdapter(adapter);
gridView.setColumnWidth(200);
// 添加点击行事件
gridView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
// 在本例中arg2=arg3
Map<String, Object> item = (Map<String, Object>) parent.getItemAtPosition(position);
// 显示所选Item的ItemText
setTitle(item.get("name").toString());
}
});
}
/**
* 简单适配器 显示图片+文字
*
* @return
*/
private SimpleAdapter getSimpleAdapter() {
// 生成动态数组,并且转入数据
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
Map<String, Object> map = new HashMap<String, Object>();
map.put("name", "宋江");
map.put("age", "33岁");
map.put("img", R.drawable.icon);
list.add(map);
map = new HashMap<String, Object>();
map.put("name", "卢俊义");
map.put("age", "32岁");
map.put("img", R.drawable.icon);
list.add(map);
map = new HashMap<String, Object>();
map.put("name", "关胜");
map.put("age", "28岁");
map.put("img", R.drawable.icon);
list.add(map);
map = new HashMap<String, Object>();
map.put("name", "林冲");
map.put("age", "30岁");
map.put("img", R.drawable.icon);
list.add(map);
map.put("name", "吴用");
map.put("age", "33岁");
map.put("img", R.drawable.icon);
list.add(map);
map = new HashMap<String, Object>();
map.put("name", "武松");
map.put("age", "32岁");
map.put("img", R.drawable.icon);
list.add(map);
map = new HashMap<String, Object>();
map.put("name", "公孙胜");
map.put("age", "28岁");
map.put("img", R.drawable.icon);
list.add(map);
map = new HashMap<String, Object>();
map.put("name", "花荣");
map.put("age", "30岁");
map.put("img", R.drawable.icon);
list.add(map);
// 生成适配器
SimpleAdapter adapter = new SimpleAdapter(this, list,
R.layout.personview, new String[] { "img",
"name","age" }, new int[] { R.id.imgHead,
R.id.tvName,R.id.tvAge });
return adapter;
}
//图片适配器
private class ImageAdapter extends BaseAdapter {
private Context mContext;
private LayoutInflater mInflater;
private List<Map<String, Object>> mData;
// 狗狗图片id集合
private Integer[] mDogs = { R.drawable.doga, R.drawable.dogb,
R.drawable.dogc, R.drawable.dogz, R.drawable.dogf, R.drawable.dogr,
R.drawable.dogl, R.drawable.dogv, R.drawable.dogu,
R.drawable.dogj,R.drawable.dogk,R.drawable.dogm,
R.drawable.dogo,R.drawable.dogs,R.drawable.dogw
};
public ImageAdapter(Context context) {
this.mContext = context;
}
@Override
public int getCount() {
return mDogs.length;
}
@Override
public Object getItem(int position) {
return mDogs[position];
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
//使用图片 其实这里也可以使用TextView
ImageView imageView;
if (convertView == null) {
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mDogs[position]);
return imageView;
}
}
}
第四步、运行效果
android开发步步为营之35:GridView的用法