更改数据后,ListView未更新

时间:2016-10-26 10:18:09

标签: android listview

我使用两个ListViews(List1有数据,List2为空)。

用户可以输入名称作为输入,如果List1包含名称并且按下了添加Button,则标记应减少1并且ListViews都应更新。

示例:

如果List1有10个标记并且输入了名称,则List1的标记应设为9,List2的标记应设为1。

如果我们这样做10次,则应删除List1名称,并将List2的标记设置为10。

示例2:

假设List1的标记设置为8,List2标记设置为2.如果按下子按钮,则应添加两个列表。此时,应删除List2,List1的总标记应为10。

以下是我使用的逻辑,但是它无法正常工作,它创建了多行并且标记无法正确更新。

HomeAct类

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

import android.app.Activity;
import android.os.Bundle; 
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;

public class HomeAct extends Activity {

List<DocItem> docDet1 = new ArrayList<DocItem>();
List<DocItem> docDet2 = new ArrayList<DocItem>();
ListView lv1, lv2;
EditText editText;
Button btn1, btn2;
DocDetAdapter adapter1, adapter2;
int n=0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.home_act);
    lv1 = (ListView)findViewById(R.id.lv_det1);
    lv2 = (ListView)findViewById(R.id.lv_det2);
    editText = (EditText)findViewById(R.id.editText1);
    btn1 = (Button)findViewById(R.id.btn1);
    btn2 = (Button)findViewById(R.id.btn2);
    adapter1 = new DocDetAdapter(1);
    adapter2 = new DocDetAdapter(2);

    docDet1.add(new DocItem("1", "john", 20));
    docDet1.add(new DocItem("2", "james", 5));
    docDet1.add(new DocItem("3", "shaun", 60));
    docDet1.add(new DocItem("4", "joy", 10));
    docDet1.add(new DocItem("5", "mark", 1));

    lv1.setAdapter(adapter1);
    lv2.setAdapter(adapter2);

    btn1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            for(int j =0;j<docDet1.size();j++){
                final DocItem curItem = docDet1.get(j);
                if(curItem.name.equals(editText.getText().toString())){
                    n++;
                 DocItem docItem = docDet1.get(j);
                    docDet1.get(j).marks = n;
                    docDet2.add(0, docItem);
                    adapter1.notifyDataSetChanged();
                    adapter2.notifyDataSetChanged();
                    editText.setText("");
                    }
                }
            editText.setText("");
        }
    });

    btn2.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            for(int j =0;j<docDet2.size();j++){
                final DocItem curItem = docDet2.get(j);
                if(curItem.name.equals(editText.getText().toString())){

                 DocItem docItem = docDet1.get(j);
                    docDet2.remove(j);
                    docDet1.add(0, docItem);
                    adapter1.notifyDataSetChanged();
                    adapter2.notifyDataSetChanged();
                    editText.setText("");
                    }
                }
            editText.setText("");
        }
    });
}

private class DocDetAdapter extends BaseAdapter {

    int mode; // 1 or 2

    public DocDetAdapter(int mode) {
        this.mode = mode;
    }

    @Override
    public int getCount() {
        if (mode == 1)
            return docDet1.size();
        else
            return docDet2.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(final int position, View convertView,
            ViewGroup parent) {
        LayoutInflater li = getLayoutInflater();

        if (convertView == null)
            convertView = li.inflate(R.layout.row_tray_det, null);

        TextView tvItemName = (TextView) convertView
                .findViewById(R.id.tv_item_name);
        TextView tvRack = (TextView) convertView.findViewById(R.id.tv_rack);
        TextView tvQty = (TextView) convertView.findViewById(R.id.tv_qty);

        DocItem invItem;
        if (mode == 1)
            invItem = docDet1.get(position);
        else
            invItem = docDet2.get(position);

        tvItemName.setText(invItem.docNo);
        tvRack.setText(invItem.name);
        tvQty.setText(invItem.marks + "");

        return convertView;
        }
    }
  }

DocItem类

public class DocItem {

public String docNo, name;
public Integer marks;

public DocItem(String docNo, String name, Integer marks) {
    super();
    this.docNo = docNo;
    this.name = name;
    this.marks = marks;
     }
  }

home_act.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical" >

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10" >
    </EditText>

    <Button
        android:id="@+id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="3"
        android:text="Add" />

    <Button
        android:id="@+id/btn2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="3"
        android:text="Sub" />
</LinearLayout>

<TextView
    android:id="@+id/textView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10"
    android:gravity="center"
    android:text="list 1"
    android:textSize="20sp"
    android:textStyle="bold" >
</TextView>

<ListView
    android:id="@+id/lv_det1"
    android:layout_width="fill_parent"
    android:layout_height="200dp"
    android:layout_marginTop="10dp" />

<TextView
    android:id="@+id/textView2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10"
    android:gravity="center"
    android:text="list 2"
    android:textSize="20sp"
    android:textStyle="bold" >
</TextView>

<ListView
    android:id="@+id/lv_det2"
    android:layout_width="fill_parent"
    android:layout_height="250dp" />

 </LinearLayout>

row_tray_det

  <?xml version="1.0" encoding="utf-8"?>
  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
    android:orientation="vertical" >

    <View
    android:id="@+id/v_doc_seperator"
    android:layout_width="match_parent"
    android:layout_height="4dp"
    android:background="@color/blue"
    android:visibility="gone" />

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/row_bg_transparent_white"
    android:gravity="center_vertical"
    android:orientation="horizontal" >

    <TextView
        android:id="@+id/tv_rack"
        style="@android:style/TextAppearance.Medium"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="5"
        android:gravity="center_vertical"
        android:padding="10dp"
        android:text="Sl no"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/tv_item_name"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:gravity="center_vertical"
        android:text="Name"
        android:textSize="15sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/tv_qty"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:ems="10"
        android:gravity="center_vertical"
        android:paddingRight="3dp"
        android:text="Marks"
        android:textSize="16sp"
        android:textStyle="bold" />
</LinearLayout>

以下是预期输出的图片: Expected Output

在上面的输出中,Joy有10个标记,如果输入“Joy”作为输入,则列表应如上所示。

我真的可以使用帮助,提前谢谢。

1 个答案:

答案 0 :(得分:2)

根据我的理解,如果在editText中输入的名称与列表中的名称匹配,则减少标记1.将相同的内容添加到列表2并将标记设置为1.

如果为同一名称列表单击“添加”,则名称的标记将减少,而list2中的标记将变为2.

对添加部分进行更改

 btn1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            DocItem changeItem = null;
            for (int i = 0; i < docDet1.size(); i++) {
                DocItem docItem = docDet1.get(i);
                if (docItem.name.equals(editText.getText().toString())) {
                    changeItem = docDet1.get(i);
                    changeItem.marks = changeItem.marks - 1;
                    if (findDocItem(editText.getText().toString()) != null) {
                        DocItem docI = findDocItem(editText.getText().toString());
                        docI.marks = docI.marks + 1;
                    } else {
                        docDet2.add(new DocItem(changeItem.docNo, changeItem.name, 1));
                    }

                }

            }

            adapter2.notifyDataSetChanged();
            adapter1.notifyDataSetChanged();
        }
    });

查找和项目

  DocItem findDocItem(String name) {
    for (DocItem item : docDet2) {
        if (item.name.equals(name)) {
            return item;
        }
    }
    return null;
}

避免在for循环中调用notifyDataSetChanged

你会为sub做类似的事情。

对于聊天

中讨论的子部分
    btn2.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            int changedmarks=0;
            for (int i = 0; i < docDet2.size(); i++) {
                DocItem docItem = docDet2.get(i);
                if (docItem.name.equals(editText.getText().toString())) {
                    changedmarks =docDet2.get(i).marks;
                    docDet2.remove(i);

                }
            }
            if(findDocItem2(editText.getText().toString())!=null )
            {
                DocItem  docitem = findDocItem2(editText.getText().toString());
                docitem.marks = docitem.marks+ changedmarks;
            }

            adapter1.notifyDataSetChanged();
            adapter2.notifyDataSetChanged();
        }
    });

然后

DocItem findDocItem2(String name) {
    for (DocItem item : docDet1) {
        if (item.name.equals(name)) {
            return item;
        }
    }
    return null;
 }