GridView自定義排序邏輯

在Android中，要為GridView實現自定義排序邏輯，你需要創建一個自定義的Comparator，并在適配器中使用它。以下是一個簡單的示例，展示了如何為GridView實現自定義排序邏輯：

1. 首先，創建一個自定義的Comparator。在這個例子中，我們將根據字符串的長度對GridView中的項進行排序：

import java.util.Comparator;

public class CustomComparator implements Comparator<String> {
    @Override
    public int compare(String s1, String s2) {
        return s1.length() - s2.length();
    }
}

2. 創建一個自定義的ArrayAdapter，并在其中使用自定義的Comparator：

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class CustomArrayAdapter extends ArrayAdapter<String> {
    private List<String> originalList;
    private List<String> sortedList;
    private CustomComparator comparator;

    public CustomArrayAdapter(@NonNull Context context, int resource, @NonNull List<String> objects, CustomComparator comparator) {
        super(context, resource, objects);
        this.originalList = new ArrayList<>(objects);
        this.sortedList = new ArrayList<>(objects);
        this.comparator = comparator;
        Collections.sort(sortedList, comparator);
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        if (convertView == null) {
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.grid_item, parent, false);
        }

        TextView textView = convertView.findViewById(R.id.text_view);
        textView.setText(sortedList.get(position));

        return convertView;
    }
}

3. 在你的Activity或Fragment中，使用自定義的CustomArrayAdapter為GridView設置適配器：

import android.os.Bundle;
import android.widget.GridView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        GridView gridView = findViewById(R.id.grid_view);

        List<String> items = new ArrayList<>();
        items.add("Item 1");
        items.add("Item 2");
        items.add("Item 3");
        items.add("Item 4");
        items.add("Item 5");

        CustomComparator comparator = new CustomComparator();
        CustomArrayAdapter adapter = new CustomArrayAdapter(this, R.layout.grid_item, items, comparator);

        gridView.setAdapter(adapter);
    }
}

現在，你的GridView將根據字符串長度進行自定義排序。你可以根據需要修改CustomComparator以實現不同的排序邏輯。