Question

我创建了一个带有一个字符串Arraylist的自定义列表视图，但我还没有添加任何重复值，但是当我在手机中运行时，列表中第9个后面的元素开始重复..所以怎么能我避免重复这一点这是我的java代码..

ListDetails.java

package com.android.mezohn.unl.model;    
import com.android.mezohn.unl.R;    
import java.util.ArrayList;
import java.util.HashSet;

public class ListDetails {    
    public static ArrayList<model> getList() {
        ArrayList<model> SystemAuditList = new ArrayList<>();
        SystemAuditList.add(new model("S1", "Access Control"));
        SystemAuditList.add(new model("S2", "Contractor Safety"));
        SystemAuditList.add(new model("S3", "PTW Standard"));
        SystemAuditList.add(new model("S4", "Incident Investigation"));
        SystemAuditList.add(new model("S5", "Technology and Subtle change"));
        SystemAuditList.add(new model("S6", "Work at height"));
        SystemAuditList.add(new model("S7", "Confined Spaces"));
        SystemAuditList.add(new model("S8", "Emergency Preparedness and EPI"));
        SystemAuditList.add(new model("S9", "Effluent Treatment and Waste Management "));
        SystemAuditList.add(new model("S10", "Storage and Handling of Hazardous chemicals"));
        SystemAuditList.add(new model("S11", "Portable Electrical Appliances"));
        SystemAuditList.add(new model("S12", "Machine Guarding"));
        SystemAuditList.add(new model("S13", "Lifting Tools"));
        SystemAuditList.add(new model("S14", "Canteen"));
        SystemAuditList.add(new model("S15", "Personal Change Management"));
        SystemAuditList.add(new model("S16", "Hazard Checklist"));
        SystemAuditList.add(new model("S17", "Hot Work"));
        SystemAuditList.add(new model("S18", "Ladder Safety Checklist"));
        SystemAuditList.add(new model("S19", "LOTO Checklist"));
        SystemAuditList.add(new model("S20", "SBO Checklist"));
        SystemAuditList.add(new model("S21", "Vehicle Marshal system Checklist"));
        SystemAuditList.add(new model("S22", "Gate,Drain and Shutter"));
        return SystemAuditList;            
    } 
}

model.java

package com.android.mezohn.unl.model;


public class model {

    private String Auditcode;
    private String SystemAudit;



    public model(String Auditcode, String SystemAudit ) {
        this.Auditcode = Auditcode;
        this.SystemAudit = SystemAudit;

    }

    public String getAuditcode() { return Auditcode; }

    public void setAuditcode(String Auditcode) {
        this.Auditcode = Auditcode;
    }


    public String getSystemAudit() { return SystemAudit; }

    public void setSystemAudit(String SystemAudit) {
        this.SystemAudit = SystemAudit;
    }
}

SystemAuditAdapter.java

    package com.android.mezohn.unl.adapter;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.android.mezohn.unl.R;
import com.android.mezohn.unl.model.model;

import java.util.ArrayList;



public class SystemauditAdapter extends BaseAdapter {

    private Context context;
    private ArrayList<model> models;


    public SystemauditAdapter(Context context, ArrayList<model> models) {
        this.context = context;
        this.models = models;
    }

    @Override
    public int getCount() {

        return models.size();
    }

    @Override
    public Object getItem(int position) {

        return models.get(position);
    }

    @Override
    public long getItemId(int position) {

        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if(convertView ==null){
            convertView = View.inflate(context, R.layout.list_view,null);

            TextView code = convertView.findViewById(R.id.cardcode);
            TextView title = convertView.findViewById(R.id.cardTitle);
            model model = models.get(position);
            code.setText(model.getAuditcode());
            title.setText(model.getSystemAudit());


        }

        return convertView;
    }
}

Answer 1

创建一个名为ViewHolder的内部类，如下所示：

static class ViewHolder {
    TextView code;
    TextView title;
}

然后修改适配器 getView（）方法，如下所示：

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    Model model = models.get(position);
    ViewHolder holder = null;
    if(convertView ==null){
        holder = new ViewHolder();
        convertView = View.inflate(context, R.layout.list_view,null);
        holder.code = convertView.findViewById(R.id.cardcode);
        holder.title = convertView.findViewById(R.id.cardTitle);
        converView.setTag(holder);    
    }else{
        holder = (ViewHolder)converView.getTag();
    }
    holder.code.setText(model.getAuditcode());
    holder.title.setText(model.getSystemAudit());

    return convertView;
}

Answer 2

如果您不想在列表中使用重复项，则可以使用HashSet。 ArrayList允许我们在其上存储重复的对象。

要删除Arraylist上的重复对象，您可以这样做：

    mesh.material = [material, material2]; //does not work

如何从arraylist中删除Duplicate值？

2 个答案: