android根据阀值动态改变背景颜色

实现原理：gridview通过baseadapter适配器，getview方法对应添加不同的布局来改变背景颜色

实现效果图：

（1）主界面布局

<GridView
    android:id="@+id/gridViews"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:numColumns="4"
    android:stretchMode="columnWidth" />

（2）单选项卡item布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="240dp"
        android:layout_height="150dp"
        android:layout_marginTop="10dp"
        android:background="@android:color/holo_red_dark"
        android:orientation="vertical">

        <TextView
            android:id="@+id/tv_tem"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="湿度"
            android:textColor="#000"
            android:textSize="32sp" />

        <TextView
            android:id="@+id/tv_num"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:gravity="center"
            android:layout_marginLeft="100dp"
            android:layout_marginTop="30dp"
            android:background="@android:color/holo_blue_dark"
            android:text="32" />
    </LinearLayout>


</LinearLayout>

（3）在activity节目添加适配器和随机数数据，如果是网络请求的话，同理

public class GridActivity extends Activity {
    private GridView gridView;
    GridviewAdapter adapter;

    private String[] enstrings = new String[] {"温度","湿度","co2","pm2.5","光照","道路状态"};

  //  private String[] ennums = new String[] {"32","80","567","324","58","456"};
    double num1=50;
    double num2=180;
    float[] temps =new float[6];
    Handler handler = new Handler();

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_grid);
        gridView = (GridView)findViewById(R.id.gridViews);


        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                try {
                    handler.postDelayed(this, 3000);
                    for (int i=0;i<6;i++){
                        temps[i]=(int)num1+(int)(Math.random()*(num2-num1));
                    }
                    Log.e("TAG","189---"+temps[1]);

                    GridviewAdapter adapter = new GridviewAdapter();
                    gridView.setAdapter(adapter);

                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }, 3000); //每隔1s执行



        GridviewAdapter adapter = new GridviewAdapter();
        gridView.setAdapter(adapter);




    }

    class GridviewAdapter extends BaseAdapter{
        TextView tv_tem,tv_num;
        @Override
        public int getCount() {
            return enstrings.length;
        }

        @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) {
            if (temps[i] < 90){
                view = LayoutInflater.from(getApplicationContext()).inflate(R.layout.gridviewlight,null);
            }else{
                view = LayoutInflater.from(getApplicationContext()).inflate(R.layout.gridview,null);
            }


            tv_tem = (TextView)view.findViewById(R.id.tv_tem);
            tv_num = (TextView)view.findViewById(R.id.tv_num);
            tv_tem.setText(enstrings[i]);
            tv_num.setText(String.valueOf(temps[i]));
            return view;
        }
    }


}