java - 在 ListView 中，所有值都插入到第一个位置

Question

下面是我的java类

字符串s的值来自数据库缓冲区， 我希望每当值到来时我都会作为第一个可点击元素存储在 ListView 中.. 但发生的情况是所有值都作为项目 1 存储在 ListView 的第一个位置

             import android.database.Cursor;
             import android.os.Bundle;
              import android.support.v7.app.AppCompatActivity;
              import android.widget.ArrayAdapter;
              import android.widget.ListView;
              import android.widget.TextView;

              import java.util.ArrayList;
               import java.util.Arrays;


      public class HistoryActivity extends AppCompatActivity {

 ListView lv;
String s= null;
TextView tv1;
DatabaseHelper mydb;
StringBuffer buffer;
private ArrayAdapter<String> listAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.acticity_history);
    lv = (ListView) findViewById(R.id.listView);
    mydb = new DatabaseHelper(this);

    Cursor res = mydb.getAllData();
    if(res.getCount() == 0)
    {
        return;

    }

    buffer = new StringBuffer();
    while(res.moveToNext()){
        buffer.append(""+ res.getString(1)+ "\n");
    }
    s = buffer.toString();

    String[] values = new String[]{s};


    ArrayList<String> planetList = new ArrayList<String>();
    planetList.addAll( Arrays.asList(values) );

    listAdapter = new ArrayAdapter<String>(this, R.layout.simpleraw, planetList);

    lv.setAdapter(listAdapter);} }     

下面是我的 ListView 的 xml 布局

    <?xml version="1.0" encoding="utf-8"?>

    <LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="fill_parent"
android:isScrollContainer="true">

<ListView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/listView"
    android:layout_gravity="center_horizontal"
    android:background="#000000"/>
</LinearLayout>

下面是我的 textview 的 simpleraw 布局文件

      <?xml version="1.0" encoding="utf-8"?>

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/rowTextView"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="10dp"
    android:textColor="#FFFFFF"
    android:textSize="16sp" >
</TextView>

Answer 1

您的所有值都将附加到 String 中。将您的代码替换为以下内容，

 @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.acticity_history);
lv = (ListView) findViewById(R.id.listView);
mydb = new DatabaseHelper(this);

Cursor res = mydb.getAllData();
if(res.getCount() == 0)
{
    return;
}

else
{
  ArrayList<String> planetList = new ArrayList<String>();
  while(res.moveToNext()){
    planetList.add(res.getString(1));
    }

    listAdapter = new ArrayAdapter<String>(this, R.layout.simpleraw, planetList);

   lv.setAdapter(listAdapter);
  }
 } 
} 

为您的 listView 设置 OnItemClickListener，

lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id)
        {
            String itemName = (String) lv.getItemAtPosition(position);
            Intent intent = new Intent(currentActivity.this,newActivity.class);
            intent.putExtra("some_string", itemName);
            startActivity(intent);
        }               
  }