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问迭代RecyclerView
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Stack Overflow用户

提问于 2022-04-24 23:13:41

回答 2查看 219关注 0票数 0

我想循环遍历所有的CardViews，并通过单击按钮改变TextView在单个CardView项目中的文本和颜色。下面的代码似乎产生了所需的结果，但我不确定它是否是最有效的代码，甚至是准确的(索引)。

// CustomAdapter

import android.view.LayoutInflater;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;

public class CustomAdapter extends RecyclerView.Adapter<CustomViewHolder> {

    private Context context;
    private List<MyModel> list;

    public CustomAdapter(Context context, List<MyModel> list) {
        this.context = context;
        this.list = list;
    }

    @NonNull
    @Override
    public CustomViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        return new CustomViewHolder(LayoutInflater.from(context).inflate(R.layout.single_items, parent, false));
    }

    @Override
    public void onBindViewHolder(@NonNull CustomViewHolder holder, int position) {
        holder.textName.setText(list.get(position).getName());
        holder.textAge.setText(String.valueOf(list.get(position).getAge()));
    }

    @Override
    public int getItemCount() {
        return list.size();
    }

}

//CustomViewHolder

import android.view.View;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

public class CustomViewHolder extends RecyclerView.ViewHolder {

    public TextView textName, textAge;

    public CustomViewHolder(@NonNull View itemView) {
        super(itemView);

        textName = itemView.findViewById(R.id.textName);
        textAge = itemView.findViewById(R.id.textAge);
    }

}
MainActivity

import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    RecyclerView recyclerView;
    List<MyModel> myModelList;
    CustomAdapter customAdapter;

    private Button button1;

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

        loadData();
    }

    private void loadData() {
        recyclerView = findViewById(R.id.recycler_main);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new GridLayoutManager(this, 1));

        myModelList = new ArrayList<>();

        myModelList.add(new MyModel("Joe", 21));
        myModelList.add(new MyModel("Jane", 26));
        myModelList.add(new MyModel("Kyle", 19));
        myModelList.add(new MyModel("Scott", 30));

        customAdapter = new CustomAdapter(this, myModelList);
        recyclerView.setAdapter(customAdapter);
    }

    public void onClickBtn(View v)
    {
        String searchString = "Kyle";

        for (int x = recyclerView.getChildCount(), i = 0; i < x; ++i) {
            RecyclerView.ViewHolder holder = recyclerView.getChildViewHolder(recyclerView.getChildAt(i));
            TextView txtName = holder.itemView.findViewById(R.id.textName);

            if (txtName.getText().toString().equals(searchString.toString())) {
                txtName.setText("Found " + txtName.getText().toString());
                txtName.setTextColor(Color.GREEN);
                customAdapter.notifyItemChanged(x);
            }
        }
    }

}

//MyModel

public class MyModel {

    String name = "";
    int age = 0;

    public MyModel(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

}

重要的是，我在按钮单击事件中迭代列表。以后要更改的功能。非常感谢你的任何建议和反馈。更新。必须是索引或其他相关问题。当我的ArrayList包含更多、更多的项目和按钮时，很多未找到的行文本和颜色都会被更改。

java

android

回答 2

Stack Overflow用户

回答已采纳

发布于 2022-04-27 10:13:25

试试这个适配器：

public class CustomAdapter extends RecyclerView.Adapter<CustomViewHolder> {

private Context context;
private List<MyModel> list;
private String searchString = "";

public CustomAdapter(Context context, List<MyModel> list) {
    this.context = context;
    this.list = list;
}

@NonNull
@Override
public CustomViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    return new CustomViewHolder(LayoutInflater.from(context).inflate(R.layout.single_items, parent, false));
}

@Override
public void onBindViewHolder(@NonNull CustomViewHolder holder, int position) {
    holder.textAge.setText(String.valueOf(list.get(position).getAge()));
    if(list.get(position).getName().equals(searchString)){
        holder.textName.setText("Found " + list.get(position).getName());
        holder.textName.setTextColor(Color.GREEN);
    } else {
        holder.textName.setText(list.get(position).getName());
        holder.textName.setTextColor(Color.BLACK);
    }
}

@Override
public int getItemCount() {
    return list.size();
}

public void setNewSearchString(String searchString) {
    this.searchString = searchString;
    notifyDataSetChanged();
}
}

然后按一下按钮：

public void onClickBtn(View v)
{
    customAdapter.setNewSearchString("Kyle");
}

对于多个搜索，适配器：

public class CustomAdapter extends RecyclerView.Adapter<CustomViewHolder> {

private Context context;
private List<MyModel> list;
//private String searchString = "";
private ArrayList<String> arraySearchStrings = new ArrayList<>();

public CustomAdapter(Context context, List<MyModel> list) {
    this.context = context;
    this.list = list;
}

@NonNull
@Override
public CustomViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    return new CustomViewHolder(LayoutInflater.from(context).inflate(R.layout.single_items, parent, false));
}

@Override
public void onBindViewHolder(@NonNull CustomViewHolder holder, int position) {
    holder.textAge.setText(String.valueOf(list.get(position).getAge()));
    boolean found = false;
    for (String searchString : arraySearchStrings) {
        if (list.get(position).getName().equals(searchString)) {
            found = true;
            break;
        }
    }
    if (found) {
        holder.textName.setText("Found " + list.get(position).getName());
        holder.textName.setTextColor(Color.GREEN);
    } else {
        holder.textName.setText(list.get(position).getName());
        holder.textName.setTextColor(Color.BLACK);
    }
}

@Override
public int getItemCount() {
    return list.size();
}

public void setNewSearchString(String searchString) {
    //this.searchString = searchString;
    arraySearchStrings.add(searchString);
    notifyDataSetChanged();
}

public void resetSearchString() {
    arraySearchStrings.clear();
    notifyDataSetChanged();
}
}

按钮单击：

public void onClickBtn(View v)
{
    customAdapter.setNewSearchString("Kyle");
    customAdapter.setNewSearchString("Steve");
    customAdapter.setNewSearchString("Joe");
}

备选回答者：

public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.CustomViewHolder> {

private Context context;
private List<MyModel> list;
private ArrayList<String> arraySearchStrings = new ArrayList<>();
private ArrayList<Boolean> arrayFound = new ArrayList<>();
private int[] arrayFoundCount;
private int foundTotalCount = 0;

public CustomAdapter(Context context, List<MyModel> list) {
    this.context = context;
    this.list = list;
    arrayFoundCount = new int[list.size()];
    for (int i = 0; i < list.size(); i++) {
        arrayFound.add(false);
        arrayFoundCount[i] = 0;
    }
}

@NonNull
@Override
public CustomViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    return new CustomViewHolder(LayoutInflater.from(context).inflate(R.layout.single_items, parent, false));
}

@Override
public void onBindViewHolder(@NonNull CustomViewHolder holder, int position) {
    holder.textAge.setText(String.valueOf(list.get(position).getAge()));
    holder.textCount.setText(String.valueOf(arrayFoundCount[position]));
    if (arrayFound.get(position)) {
        holder.textName.setText("Found " + list.get(position).getName());
        holder.textName.setTextColor(Color.GREEN);
    } else {
        holder.textName.setText(list.get(position).getName());
        holder.textName.setTextColor(Color.BLACK);
    }
}

@Override
public int getItemCount() { return list.size(); }

public class CustomViewHolder extends RecyclerView.ViewHolder {

    public TextView textName, textAge, textCount;

    public CustomViewHolder(@NonNull View itemView) {
        super(itemView);
        textName = itemView.findViewById(R.id.textName);
        textAge = itemView.findViewById(R.id.textAge);
        textCount = itemView.findViewById(R.id.textCount);
    }
}

private int countFoundNameInList() {

    int count = 0;
    boolean found;
    MyModel model;

    arrayFound.clear();
    for (int i = 0; i < list.size(); i++) {
        model = list.get(i);
        found = false;
        for (String searchString : arraySearchStrings) {
            if (model.getName().equals(searchString)) {
                found = true;
                arrayFoundCount[i] = arrayFoundCount[i]++;
                count++;
                break;
            }
        }
        arrayFound.add(found);
    }
    return count;
}

public void setNewSearchString(String searchString) {
    arraySearchStrings.add(searchString);
    int newCount = countFoundNameInList();
    if (newCount > foundTotalCount) {
        Toast.makeText(context, searchString + " found.", Toast.LENGTH_SHORT).show();
    } else {
        Toast.makeText(context, "Error: Nothing found!!", Toast.LENGTH_LONG).show();
    }
    foundTotalCount = newCount;
    notifyDataSetChanged();
}
}

票数 1

Stack Overflow用户

发布于 2022-04-25 04:47:05

我不认为这个代码会给你准确的结果。您必须想出不同的逻辑，在您的逻辑中，您正在搜索静态名称，我确信这只是为了演示目的。稍后，您将使用用户输入字符串实现。因此，根据我的意见，您可以在适配器中创建变量，即搜索模式是on或off --当用户开始搜索时，使searchMode打开；与在您的viewHolder类中搜索set searchMode Off时相同，您可以在关闭状态的searchMode上进行更新。您可以创建2个列表，1表示主列表，秒表示搜索列表，当用户开始搜索时，您必须使用搜索字符串过滤主列表，然后将其设置为searchedList，然后将searchMode设置为On，然后将其更新到适配器。rest将处理您的适配器。不需要一个一个地从你的名单上修改。

根据我的意见，我在这里添加所需的更改。

您的自定义适配器

public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.CustomViewHolder> {

   private Context context;
   private List<MyModel> list;
   private Boolean isSearchModeOn = false;

   public CustomAdapter(@NonNull Context context, @NonNull List<MyModel> list) {
      this.context = context;
      this.list = list;
   }

   @NonNull
   @Override
   public CustomViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
      return new CustomViewHolder(LayoutInflater.from(context).inflate(R.layout.single_items, parent, false));
   }

   @Override
   public void onBindViewHolder(@NonNull CustomViewHolder holder, int position) {
      if (isSearchModeOn){
         holder.textName.setText("Found " + list.get(position).getName());
         holder.textName.setTextColor(Color.GREEN);
      }else {
         holder.textName.setText(list.get(position).getName());
         //Also set Here normal text color
      }
      holder.textAge.setText(String.valueOf(list.get(position).getAge()));
   }

   @SuppressLint("NotifyDataSetChanged")
   public void updateList(@NonNull List<MyModel> searchedList){
      list = searchedList;
      notifyDataSetChanged();
   }

   @SuppressLint("NotifyDataSetChanged")
   public void setSearchMode(@NonNull Boolean isOn){
      isSearchModeOn = isOn;
      notifyDataSetChanged();
   }

   @Override
   public int getItemCount() {
      return list.size();
   }

   public class CustomViewHolder extends RecyclerView.ViewHolder {

      @NonNull
      public TextView textName, textAge;

      public CustomViewHolder(@NonNull View itemView) {
         super(itemView);

         textName = itemView.findViewById(R.id.textName);
         textAge = itemView.findViewById(R.id.textAge);
      }

   }

}

MainActivity

public class MainActivity extends AppCompatActivity {

    RecyclerView recyclerView;
    List<MyModel> myModelList;
    List<MyModel> searchedList;
    CustomAdapter customAdapter;

    @Override
    protected void onCreate(@NonNull Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test);
        loadData();
    }

    private void loadData() {
        recyclerView = findViewById(R.id.recyclerView);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new GridLayoutManager(this, 1));

        myModelList = new ArrayList<>();

        myModelList.add(new MyModel("Joe", 21));
        myModelList.add(new MyModel("Jane", 26));
        myModelList.add(new MyModel("Kyle", 19));
        myModelList.add(new MyModel("Scott", 30));

        customAdapter = new CustomAdapter(this, myModelList);
        recyclerView.setAdapter(customAdapter);
    }

    public void onClickBtn(@NonNull View v)
    {
        String searchString = "Kyle";
        searchedList = new ArrayList<>();

        for (int x = myModelList.size(), i = 0; i < x; ++i) {
            if (myModelList.get(i).getName().equals(searchString)){
                searchedList.add(myModelList.get(i));
            }
        }
        customAdapter.updateList(searchedList);
        customAdapter.setSearchMode(true);
    }
}

我主要是用kotlin开发的，所以在这段代码中可能会出现一些文本错误。您可以检查此需求的逻辑。

票数 0

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/71993078

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