频道管理

//在工作空间里面加的
allprojects {
    repositories {
        google()
        jcenter()
        maven {url "https://jitpack.io"}
    }
}
//demo里面添加依赖
implementation 'com.github.andyoom:draggrid:v1.0.1'

 button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (list==null){//判断集合中是否已有数据，没有则创建
                    list=new ArrayList<>();

                    //第一个是显示的条目，第二个参数是否显示
                    list.add(new ChannelBean("热点",true));
                    list.add(new ChannelBean("军事",true));
                    list.add(new ChannelBean("八卦",true));
                    list.add(new ChannelBean("游戏",true));
                    list.add(new ChannelBean("宠物",true));
                    list.add(new ChannelBean("汽车",false));
                    list.add(new ChannelBean("热卖",false));
                    list.add(new ChannelBean("外卖",false));
                    list.add(new ChannelBean("太阳花",false));
                    list.add(new ChannelBean("九三",false));
                    list.add(new ChannelBean("八嘎",false));
                    list.add(new ChannelBean("色昂",false));

                    ChannelActivity.startChannelActivity(MainActivity.this,list);

                }else if (jsonStr!=null){//当判断保存的字符串不为空的时候，直接加载已经有了的字符串

                    ChannelActivity.startChannelActivity(MainActivity.this,jsonStr);

                }
            }

  @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode==ChannelActivity.REQUEST_CODE&&resultCode==ChannelActivity.RESULT_CODE) {
            jsonStr = data.getStringExtra(ChannelActivity.RESULT_JSON_KEY);
        }
    }