Question

当我点击主要活动列表中的某些数据时，我想在我的数据库中将COLUMN_INGRIDIENTS列中的值显示到另一个活动中的TextView。

main.xml中

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

    <ListView
        android:id="@+id/myListView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" >
   </ListView>

</LinearLayout>

list.xml

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

    <TextView
        android:id="@+id/recipeText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="" />

</LinearLayout>

Main.java

package com.example.viewer;



import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.CursorAdapter;
import android.widget.ListView;
import android.widget.TextView;


public class Main extends Activity {

public final static String TAG_INGRIDIENTS="com.example.getlistfromdb.INGRIDIENTS";


private recipelistHelper dbrecipelistHelper = null;
private Cursor ourCursor = null;
private recipeAdapter adapter = null;


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

    ListView myListView = (ListView) findViewById(R.id.myListView);

    dbrecipelistHelper = new recipelistHelper(this);

    dbrecipelistHelper.createDatabase();

    dbrecipelistHelper.openDatabase();

    ourCursor=dbrecipelistHelper.getCursor();

    startManagingCursor(ourCursor);

    adapter = new recipeAdapter(ourCursor);

    myListView.setAdapter(adapter);


    myListView.setOnItemClickListener(onListClick);

    }
    catch (Exception e)
    {

        Log.e("ERROR", "ERROR IN CODE: " + e.toString());   

        e.printStackTrace();

    }


}


private AdapterView.OnItemClickListener onListClick = new  AdapterView.OnItemClickListener() 

{
    public void onItemClick(AdapterView<?> parent, View view, int position, long id)

    {



        Intent i=new Intent(Main.this, Activity2.class);
        String ingridients = null;
        i.putExtra(TAG_INGRIDIENTS,ingridients);
        startActivity(i);

    }

};



class recipeAdapter extends CursorAdapter {

    recipeAdapter(Cursor c){
        super(Main.this, c);
    }

    @Override
    public  void bindView (View row, Context ctxt, Cursor c)
    {
        recipeHolder holder = (recipeHolder)row.getTag();
        holder.populateFrom(c, dbrecipelistHelper);
    }
    @Override
    public  View newView(Context ctxt, Cursor c, ViewGroup parent)
    {
        LayoutInflater inflater = getLayoutInflater();
        View row=inflater.inflate(R.layout.list, parent, false);
        recipeHolder holder = new recipeHolder(row);
        row.setTag(holder);
        return(row);
    }


}

static class recipeHolder {
    private TextView name=null;

    recipeHolder(View row){
        name=(TextView)row.findViewById(R.id.recipeText);
    }

    void populateFrom(Cursor c, recipelistHelper r){
        name.setText(r.getName(c));
    }

}

}

Activity2.java

package com.example.viewer;


import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;



public class Activity2 extends  Activity {

String ingridients = null;
String procedure = null;

private TextView txtIngridients = null;
private TextView txtProcedure = null;




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

    ingridients=this.getIntent().getStringExtra(Main.TAG_INGRIDIENTS);
    //procedure=this.getIntent().getStringExtra(Main.TAG_PROCEDURE);

    txtIngridients=(TextView)findViewById(R.id.ingridientText);
    //txtProcedure=(TextView)findViewById(R.id.procedureText);



    txtIngridients.setText(ingridients);
    //txtProcedure.setText(procedure);


  }
}

view.xml用

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

<TextView
    android:id="@+id/ingridientText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_marginTop="29dp"
    android:text="A" />



</RelativeLayout>

Answer 1

使用adapter.getItem获取ListView中所选行的光标：

public void onItemClick(AdapterView<?> parent, View view, int position, long id)
    {
        Cursor selectedCursor=(Cursor)adapter.getItem(position);
        // get  ingridients coulmn value from selectedCursor
        selectedCursor.moveToPosition(position);  
        String ingridients = dbrecipelistHelper.getName(selectedCursor);
        // your code here
    }

Answer 2

在onItemClickListener中，为字符串赋值null：

String ingridients = null;

并将此String传递给下一个Activity。这将为null。在初始化ingridients变量并将其设置为所需的String之前，必须获取数据。

Android如何在Android中的另一个活动中将字符串值从数据库传递到TextView？

2 个答案: