Question

为什么我在这里说错误这个数组列表代码我尝试了很多我没有找到解决方案请帮忙

*public class* MainActivity extends AppCompatActivity {

**@Override**
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ArrayList<Listitem> Items = new ArrayList<Listitem>();
    Items.add(new Listitem("Noor", "Derna"));
    Items.add(new Listitem("MERO", "Derna"));
    Items.add(new Listitem("Noor", "Derna"));
    Items.add(new Listitem("Noor", "Derna"));

    **mycustomadapter myadabter = new mycustomadapter(Items);**

    **ListView Ls = (ListView) findViewById(R.id.listView); 
    Ls.setAdapter(myadabter);
Ls.setOnClickListener(new AdapterView.OnItemClickListener() {**


        **@Override**
        *public void onItemClick (AdapterView<?> parent, View view, int position, long id) {*

            TextView txtname = (TextView) view.findViewById(R.id.txt_name);
            TextView txtdisc = (TextView) view.findViewById(R.id.txt_disc);
            Toast.makeText(getApplicationContext(), txtname.getText(), Toast.LENGTH_LONG).show();
        }
    });
}





class  mycustomadapter extends BaseAdapter
{
    ArrayList<Listitem> Items=new ArrayList<Listitem>(); array list
    mycustomadapter(ArrayList<Listitem> Items){
    this.Items=Items;
    }
    @Override
    public int getCount() {
        return Items.size();
    }

    @Override
    public Object getItem(int position) {
        return Items.get(position).Name;
    }

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

    @Override
    public View getView(int i, View View, ViewGroup viewGroup) {
        LayoutInflater Linflater=getLayoutInflater(); 
        View view1 = Linflater.inflate(R.layout.raw_view,null); الview1يمثل الraw_item
        TextView txtname=(TextView)view1.findViewById(R.id.txt_name);
        TextView txtdisc=(TextView)view1.findViewById(R.id.txt_disc);
        txtname.setText(Items.get(i).Name);
        txtdisc.setText(Items.get(i).Desc);

        array list
        return view1;


    }
}

}`ListView Ls =（ListView）findViewById（R.id.listView）; //اتصالبالليستفيو Ls.setAdapter（myadabter）; Ls.setOnClickListener（new AdapterView.OnItemClickListener（）{

        @Override
        public void onItemClick (AdapterView<?> parent, View view, int position, long id) {

            TextView txtname = (TextView) view.findViewById(R.id.txt_name);
            TextView txtdisc = (TextView) view.findViewById(R.id.txt_disc);
            Toast.makeText(getApplicationContext(), txtname.getText(), Toast.LENGTH_LONG).show();
        }
    });
}`

Answer 1

你为什么要在Listview中使用on-clickList？??无论你在做什么，这都是......

Ls.setOnClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick (AdapterView<?> parent, View view, int position, long id) {

            TextView txtname = (TextView) view.findViewById(R.id.txt_name);
            TextView txtdisc = (TextView) view.findViewById(R.id.txt_disc);
            Toast.makeText(getApplicationContext(), txtname.getText(), Toast.LENGTH_LONG).show();
        }
    });
}`

这是完全错误的..如果您想点击listview项目并从您点击的项目中获取文本，那么就这样做，

 Ls.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {

                Toast.makeText(MainActivity.this, Items.get(position).getName() + " " + Items.get(position).getDesc(), Toast.LENGTH_SHORT).show();

            }
        });

清除你的困惑，这里是完整的代码，

public class MainActivity extends AppCompatActivity {

    ListView Ls;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Ls = (ListView) findViewById(R.id.listView);


        final ArrayList<Listitem> Items = new ArrayList<Listitem>();
        Items.add(new Listitem("Noor", "Derna"));
        Items.add(new Listitem("MERO", "Derna"));
        Items.add(new Listitem("Noor", "Derna"));
        Items.add(new Listitem("Noor", "Derna"));

        final mycustomadapter myadabter = new mycustomadapter(Items);
        Ls.setAdapter(myadabter);

        Ls.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {

                Toast.makeText(MainActivity.this, Items.get(position).getName() + " " + Items.get(position).getDesc(), Toast.LENGTH_SHORT).show();

            }
        });

    }

    class mycustomadapter extends BaseAdapter {
        ArrayList<Listitem> Items = new ArrayList<Listitem>();
        public TextView txtname, txtdisc;
        LayoutInflater Linflater;

        mycustomadapter(ArrayList<Listitem> Items) {
            this.Items = Items;
        }

        @Override
        public int getCount() {
            return Items.size();
        }

        @Override
        public Object getItem(int position) {
            return Items.get(position).name;
        }

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

        @Override
        public View getView(int i, View View, ViewGroup viewGroup) {
            Linflater = getLayoutInflater();
            View view1 = Linflater.inflate(R.layout.raw_view, null);
            txtname = (TextView) view1.findViewById(R.id.txt_name);
            txtdisc = (TextView) view1.findViewById(R.id.txt_disc);
            txtname.setText(Items.get(i).name);
            txtdisc.setText(Items.get(i).desc);


            return view1;


        }
    }
}

Answer 2

为了制作array-list final，因为你已经在onCreate（）中声明了它，并且在onItemClick监听器中使用它时你必须使它成为最终的。

如果你不想让它成为最终版，你可以将array-list声明为全局，并在onCreate（）中初始化它，然后你不需要使它成为最终的。

是的，您可以从适配器初始化中删除final。它不会影响代码。

AdapterView.OnItemClickListener中的错误

2 个答案: