Android UI 实现老虎机详解及实例代码

 1.布局添加Listview

 2.找到listview

 3.创建一个Adapter适配器继承BaseAdapter，封装4个方法，其中getcount,getview必须封装
   getcount:告诉listview要显示的条目数
   getview：告诉listview每个条目显示的内容。
 4.创建Adapter的一个对象，设置给listview。
     listview.setAdapter(ListAdapter adapter);

 TextView view = null;
   if(convertView != null){//判断converView是否为空，不为空重新使用
     view = (TextView) convertView;
   }else{
     view = new TextView(mContext);//创建一个textView对象
   }
   return view；

public class MainActivity extends AppCompatActivity {
  //1，声明控件LISTVIEW
  private ListView listView1;
  private ListView listView2;
  private ListView listView3;
  private Context mContext;


  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //2，获取控件的id
    listView1 = (ListView)findViewById(R.id.list_item1);
    listView2 = (ListView)findViewById(R.id.list_item2);
    listView3 = (ListView)findViewById(R.id.list_item3);
    mContext = this;
    //3,进行绑定
    MyAdapter myAdapter = new MyAdapter();
    listView3.setAdapter(myAdapter);
    listView2.setAdapter(myAdapter);
    listView1.setAdapter(myAdapter);
  }
  //创建适配器类实现接口
  class MyAdapter extends BaseAdapter{
    @Override
    public int getCount() {
      return 50;
    }

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

    @Override
    public long getItemId(int i) {
      return 0;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
      //声明一个textview对象
      TextView view0 = null;
      //进行判断是否能过复用
      if(view != null){
        view0 = (TextView)view;
      }else {
        view0 = new TextView(mContext);
      }
      view0.setTextSize(40);
      Random random = new Random();
      int num = random.nextInt(100);
      if(num<20){
        view0.setText("桃");
        view0.setTextColor(Color.parseColor("#ff00ff"));
      }else if(num<40){
        view0.setText("梨");
        view0.setTextColor(Color.YELLOW);
      }else if(num<60){
        view0.setText("枣");
        view0.setTextColor(Color.RED);
      }else if(num<80){
        view0.setText("橘");
        view0.setTextColor(Color.parseColor("#d4824f"));
      }else{
        view0.setText("杏");
        view0.setTextColor(Color.parseColor("#00ff00"));
      }


      return view0;
    }
  }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context="com.wenkai.tigerlistview.MainActivity">

  <ListView
    android:id="@+id/list_item1"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1" />
  <ListView
    android:id="@+id/list_item2"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1" />
  <ListView
    android:id="@+id/list_item3"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1" />

</LinearLayout>