Question

我喜欢制作按钮以便在页面中排列。

但是按钮的数量取决于数据库中存储的数据的数量。

为此，每个按钮都有一个存储在数据库中的标题。

按钮在页面中显示良好，但我无法使它们可点击。

    private void displayGridView() {
    final Cursor cursor = MessagesBDD.fetchAllMessage();

    // The desired columns to be bound
    String[] columns = new String[]{MessagesBDD.COL_TITRE,};

    final GridView gridview = (GridView) findViewById(R.id.fragboutton);
    int[] to = new int[]{R.id.button9,};
    final SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.fragment_button, cursor, columns, to, 0);

    gridview.setAdapter(adapter);

}

在OnCreate中：

        //Création d'une instance de ma classe MessageBDD
    MessagesBDD messageBdd = new MessagesBDD(this);

    //On ouvre la base de données pour écrire dedans
    messageBdd.open();

    //Generate ListView from SQLite Database
    displayGridView();
    //Récupère le fragment permettant d'accèder à la liste des contacts

我的数据库：

public class Message {

private int id;
private String titre;
private String contenu;

public Message(){}

public Message(String titre, String contenu){
    this.titre = titre;
    this.contenu = contenu;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getTitre() {
    return titre;
}

public void setTitre(String titre) {
    this.titre = titre;
}

public String getContenu() {
    return contenu;
}

public void setContenu(String contenu) {
    this.contenu = contenu;
}

public String toString(){
    return "ID : "+id+"\ntitre : "+titre+"\nContenu : "+contenu;
}

Methode fetchAllMessage：

    public static Cursor fetchAllMessage() {

    Cursor mCursor = bdd.query(TABLE_MESSAGES, new String[] {COL_ID, COL_TITRE, COL_CONTENU}, null, null, null, null, null);

    if (mCursor != null) {
        mCursor.moveToFirst();
    }
    return mCursor;
}

感谢您的帮助

Answer 1

在活动中创建方法

public ArrayList<Message> fetchAllMessage()
 {
  ArrayList<Message> mArrayList = new ArrayList<>();

  Cursor mCursor = bdd.query(TABLE_MESSAGES, new String[]{COL_ID, COL_TITRE, COL_CONTENU}, null, null, null, null, null);

  if (mCursor != null)
  {
   mCursor.moveToFirst();

   mCursor.moveToFirst();
   while (!mCursor.isAfterLast())
   {
    Message message = new Message();
    message.setTitre(mCursor.getString(mCursor.getColumnIndex(COL_TITRE)));
    message.setId(mCursor.getInt(mCursor.getColumnIndex(COL_ID)));
    message.setContenu(mCursor.getString(mCursor.getColumnIndex(COL_CONTENU)));
    mArrayList.add(message);
    mCursor.moveToNext();
   }
  }
  return mArrayList;

 }

添加set gridview adapter

ButtonAdapter adapter = new ButtonAdapter（this，fetchAllMessage）;

gridview.setAdapter（适配器）;

ButtonAdapter.java

public class ButtonAdapter extends BaseAdapter
{
 private Context mContext;
 ArrayList<Message> list;
 // Gets the context so it can be used later
 public ButtonAdapter(Context c, ArrayList<Message> list) {
  mContext = c;
  this.list = list;
 }

 // Total number of things contained within the adapter
 public int getCount() {
  return list.size();
 }

  // Require for structure, not really used in my code.
 public Object getItem(int position) {
  return null;
 }

 // Require for structure, not really used in my code. Can
 // be used to get the id of an item in the adapter for 
 // manual control. 
 public long getItemId(int position) {
  return position;
 }

 public View getView(int position,
                     View convertView, ViewGroup parent) {
  Button btn;
  if (convertView == null) {  
   // if it's not recycled, initialize some attributes
   btn = new Button(mContext);
   btn.setLayoutParams(new GridView.LayoutParams(100, 55));
   btn.setPadding(8, 8, 8, 8);
   } 
  else {
   btn = (Button) convertView;
  }
  btn.setText(list.get(position).getTitre());
  // filenames is an array of strings
  btn.setTextColor(Color.WHITE);
  btn.setBackgroundResource(R.drawable.button);
  btn.setId(position);

  return btn;
 }
}

gridview中的按钮与数据库

1 个答案: