GridView三種介面卡加點選事件《個人筆記》
阿新 • • 發佈：2019-01-24
終於全理解了
SimpleAdapter
第一種自己寫的簡單介面卡
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.SimpleAdapter;
import java.util.ArrayList;
import java.util.HashMap;
import BaseAdapter
第二種抄前輩的做了改動，好像比簡單介面卡多了優化
package com.moon.overgridview;
import java.util.ArrayList;
import java.util.List;
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.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class MainActivity extends Activity {
//宣告gridView
private GridView gridView;
//圖片的文字標題
private String[] titles = new String[]
{"pic1", "pic2", "pic3", "pic4", "pic5", "pic6", "pic7", "pic8", "pic9"};
//圖片ID陣列
private int[] images = new int[]{
R.drawable.pic1, R.drawable.pic2, R.drawable.pic3,
R.drawable.pic4, R.drawable.pic5, R.drawable.pic6,
R.drawable.pic7, R.drawable.pic8, R.drawable.pic9
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//例項化控制元件
gridView = (GridView) findViewById(R.id.gridview);
//新建自定義介面卡
PictureAdapter adapter = new PictureAdapter(titles, images, this);
//載入介面卡
gridView.setAdapter(adapter);
//載入點選事件監聽器
gridView.setOnItemClickListener(new OnItemClickListener()
{
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
Toast.makeText(MainActivity.this, "pic" + (position + 1), Toast.LENGTH_SHORT).show();
}
});
}
}
//自定義介面卡
class PictureAdapter extends BaseAdapter {
private LayoutInflater inflater;
//宣告變數
private List<Picture> pictures;
public PictureAdapter(String[] titles, int[] images, Context context)
{
super();
//把適配型別例項化
pictures = new ArrayList<Picture>();
//這一行沒看懂,感覺沒什麼用,為什麼不在下面寫,佈局有問題
inflater = LayoutInflater.from(context);
//填充資料來源
for (int i = 0; i < images.length; i++) {
Picture picture = new Picture(titles[i], images[i]);
pictures.add(picture);
}
}
@Override
// 獲取有幾項資料
public int getCount() {
if (null != pictures) {
return pictures.size();
} else {
return 0;
}
}
//....
@Override
public Object getItem(int position) {
return pictures.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
//返回每一項的顯示內容
public View getView(int position, View convertView, ViewGroup parent) {
//優化內容
ViewHolder viewHolder;
//如果conview是空
if (convertView == null) {
//把xml檔案id轉化為一個view物件
convertView = inflater.inflate(R.layout.picture_item, null);
//建立物件
viewHolder = new ViewHolder();
//將控制元件放在viewholder中
viewHolder.title = (TextView) convertView.findViewById(R.id.title);
viewHolder.image = (ImageView) convertView.findViewById(R.id.image);
//用setTag方法將viewHolder在View中儲存
convertView.setTag(viewHolder);
} else {
//從view中取出
viewHolder = (ViewHolder) convertView.getTag();
}
//顯示圖片和文字
viewHolder.image.setImageResource(pictures.get(position).getImageId());
viewHolder.title.setText(pictures.get(position).getTitle());
return convertView;
}
}
class ViewHolder//內部類ViewHolder對控制元件例項進行快取
{
public TextView title;
public ImageView image;
}
class Picture//介面卡的適配型別
{
private String title;//圖片名字
private int imageId;//圖片的資源id
public Picture(String title, int imageId)//這裡總感覺他寫的有點多,我刪了一部分多餘的程式碼
{
super();
this.title = title;
this.imageId = imageId;
}
public String getTitle()
{
return title;
}//其實還可以精簡的
public int getImageId()
{
return imageId;
}
}第三種自己臨時寫的ArrayAdapter介面卡gridview
臨時寫的沒加註釋
先建立一個實體類作為介面卡泛型
public class Character {
private int imageId;
private String name;
public Character(String name, int imageId) {
this.imageId = imageId;
this.name = name;
}
public int getImageId(){
return imageId;
}
public String getName(){
return name;
}
}
然後建立介面卡佈局和在主佈局中寫入一個gridview控制元件設id，接著新建自定義介面卡
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.List;
public class MyAdapter extends ArrayAdapter<Character>{
public int resourceId;
public MyAdapter(Context context, int textViewResourceId, List objects) {
super(context,textViewResourceId, objects);
resourceId =textViewResourceId;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Character character = getItem(position);//獲得例項
View view;
ViewHoleder viewHoleder;
if (convertView == null){
view = LayoutInflater.from(getContext()).inflate(resourceId,null);
viewHoleder = new ViewHoleder();
viewHoleder.fruitImage = (ImageView) view.findViewById(R.id.image);
viewHoleder.fruitName = (TextView) view.findViewById(R.id.text);
view.setTag(viewHoleder);
}else {
view = convertView;
viewHoleder = (ViewHoleder) view.getTag();
}
viewHoleder.fruitImage.setImageResource(character.getImageId());
viewHoleder.fruitName.setText(character.getName());
return view;
}
class ViewHoleder{
ImageView fruitImage;
TextView fruitName;
}
}最後寫入MainActivity中程式碼
import android.app.Activity;
import android.os.Bundle;
import android.widget.GridView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends Activity {
private List<Character> list = new ArrayList<Character>();
private int[] image1={R.drawable.pic1,R.drawable.pic2,R.drawable.pic3};
private String name[] ={"1","2","3"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addList();//初始化陣列
//新建介面卡
MyAdapter adapter =new MyAdapter(this,R.layout.gridview_item,list);
GridView gridView = (GridView) findViewById(R.id.main_gridlayout);
gridView.setAdapter(adapter);
}
//新增資料來源
private void addList() {
for (int i=0; i<image1.length ;i++){
list.add(new Character(name[i],image1[i]));
}
}
}