第二十五天 ListView

ListView

在value下定義顏色

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="red">#ff0000</color>//紅色:ff0000
    <color name="white">#ffffff</color>//白色:ffffff
</resources>

getView方法中，convertView（性能優化：減少內存，提高速度）

水果的例子：
Fruit類：

public class Fruit {
    private String name;
    private int img;
//  private boolean isChecked;
    public String getName() {
        return name;
    }

    public int getImg() {
        return img;
    }

    public Fruit(String name, int img) {
        this.name = name;
        this.img = img;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setImg(int img) {
        this.img = img;
    }

//    public boolean isChecked(){
//        return isChecked;
//    }
//
//    public void setIsChecked(boolean isChecked) {
//        this.isChecked = isChecked;
//    }
}

FruitAdapter

public class FruitAdapter extends BaseAdapter {
    private LayoutInflater mInflater;
    private List<Fruit> mFruit;
    private boolean[] mAllCheckBox;

    public FruitAdapter(LayoutInflater inflater, List<Fruit> fruit) {
        mInflater=inflater;
        mFruit=fruit;
        mAllCheckBox=new boolean[fruit.size()];
    }

    public void itemSelect(int position){
      mAllCheckBox[position]=!mAllCheckBox[position];
      notifyDataSetChanged();
    }

    //全選方法
    public void checkedAll() {
        for(int i=0;i<mAllCheckBox.length;i++){
            mAllCheckBox[i]=true;
            notifyDataSetChanged();
        }
    }

    //反選方法
    public void checkedOther(){
        for (int i=0;i<mAllCheckBox.length;i++){
            mAllCheckBox[i]=! mAllCheckBox[i];
            notifyDataSetChanged();
        }
    }
    @Override
    public int getCount() {
        return mFruit.size();
    }

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

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

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        Fruit fruit=mFruit.get(position);
        ViewHolder vh=null;
        if (convertView==null){
            vh=new ViewHolder();
            convertView=mInflater.inflate(R.layout.item_fruit,null);
            vh.checkBox= (CheckBox) convertView.findViewById(R.id.checkbox);
            vh.imageView= (ImageView) convertView.findViewById(R.id.imageview);
            vh.textView= (TextView) convertView.findViewById(R.id.textview);
            convertView.setTag(vh);
        }else{
            vh= (ViewHolder) convertView.getTag();
        }
        vh.textView.setText(fruit.getName());
        vh.imageView.setImageResource(fruit.getImg());
        vh.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
//              mFruit.get(position).setIsChecked(isChecked);
                mAllCheckBox[position]=isChecked;
                notifyDataSetChanged();
            }
        });
//        vh.checkBox.setChecked(fruit.isChecked());
          vh.checkBox.setChecked(mAllCheckBox[position]);
        return convertView;
    }

    //緩存數據
    class ViewHolder{
        ImageView imageView;
        CheckBox checkBox;
        TextView textView;
    }
}

FruitActivity

public class FruitActivity extends Activity {
    private ListView mListView;
    private List <Fruit> mFruit;
    private FruitAdapter mAdapter;
    private Button mButtonHeader;
    private Button mButtonFooter;
    private View viewHeader;
    private View viewFooter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listview_layout);
        mListView= (ListView) findViewById(R.id.listview);
        LayoutInflater inflater=getLayoutInflater();
        initData();
        mAdapter=new FruitAdapter(inflater,mFruit);

        //頂部添加全選按鈕
        viewHeader=inflater.inflate(R.layout.header_layout,null);
        mButtonHeader= (Button) viewHeader.findViewById(R.id.button_selectAll);
        mButtonHeader.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mAdapter.checkedAll();
            }
        });
        mListView.addHeaderView(viewHeader);


        //底部添加反選按鈕
        viewFooter=inflater.inflate(R.layout.footer_layout,null);
        mButtonFooter= (Button) viewFooter.findViewById(R.id.footer);
        mButtonFooter.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mAdapter.checkedOther();
            }
        });
        mListView.addFooterView(viewFooter);

        //對ListView監聽
        mListView.setAdapter(mAdapter);
        mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
               mAdapter.itemSelect(position-1);//不減1會數組越界
                Log.d("FRIUT","選中的水果是"+mFruit.get(position-1).getName());
            }
        });
    }
    private void initData() {
        mFruit=new ArrayList<>();
        for(int i=0;i<5;i++) {
            Fruit apple=new Fruit("蘋果",R.mipmap.apple);
            Fruit apricot=new Fruit("杏子",R.mipmap.apricot);
            Fruit banana=new Fruit("香蕉",R.mipmap.banana);
            mFruit.add(apple);
            mFruit.add(apricot);
            mFruit.add(banana);
        }
    }
}

---

ListView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
<ListView
    android:id="@+id/listview"
    android:cacheColorHint="#00000000"//添加透明色
    android:divider="#ff0000"//添加紅色分隔線
    android:dividerHeight="2dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
</ListView>
</LinearLayout>