小编use*_*404的帖子

我有下面的代码,我试图围绕PerlinNoise(x,z),所以我把它等于Yscale并试图绕过它.问题是我得到了该行的错误"当前上下文中不存在名称`Math'".有任何想法吗？

using UnityEngine;
using System.Collections;

public class voxelcreate : MonoBehaviour {
private int origin = 0;
private Vector3 ChunkSize = new Vector3 (32,6,32);
private float Height = 10.0f;
private float NoiseSize = 10.0f;
private float Yscale=0;
private GameObject root;
public float PerlinNoise(float x, float y)
{
    float noise = Mathf.PerlinNoise( x / NoiseSize, y / NoiseSize );
    return noise * Height;

}

// Use this for initialization
void Start () {
    for(int x = 0; x < 33; x++){
        bool …

我正在按照教程制作数据库光标,但是我遇到了一个问题.当我编写下面的代码时,我没有选择在数据库名称后添加查询:

public String getData(){
    db.open();
    Cursor c = db.   ;
    return none;
}

db是我的数据库名称.我想知道是否有人知道为什么它不给我选择.当我输入查询时,它表示在DBAdapter中不存在hat.我是否必须在DBAdapter类中添加一些内容？如果是这样,我还需要添加什么？

这是我的Activity Java:

package com.course.ucas;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Toast;
import android.database.sqlite.SQLiteDatabase; 

public class DatabaseActivity extends Activity {
/** Called when the activity is first created. */
DBAdapter db;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

DBAdapter db = new DBAdapter(this);
db.open();
long id;
id = db.insertTitle(
"UNIVERSITY OF ABERDEEN","Computer Science",310,84,0,"BBB","");
id = db.insertTitle( …