我们可以在数据库中显示所有记录没有问题。当我们尝试限制要使用sql显示的项目时选择搜索并正确填充RecyclerView适配器。 在列表视图中选择项目时代码失败。列表视图没有得到关于此记录的位置的消息，因此当我们从ListActivity导航到DetailActivity视图时，视图不是ListView中的项目 我的问题是如何管理适配器使用的位置变量？ 这个代码流如下按钮点击MainActivity设置搜索变量转到ListActivity，它调用DBHelper，返回ListActivity with modelList和Array List是设计是MVP所以我们在下面有一个Model Class相关代码< / p>
主要活动btn点击
public void findAllData(View view){
selectSTRING = etFromDate.getText().toString();
Intent intent = new Intent( MainActivity.this, ListActivity.class );
startActivity( intent );
}
ListActivity调用DBHelper注释掉行获取所有数据
helpher = new DBHelper(this);
dbList = new ArrayList<>();
dbList = helpher.getRangeDataFromDB();
//dbList = helpher.getDataFromDB();
DBHelper代码最终获取所选记录
public List<DBModel> getRangeDataFromDB() {
List<DBModel> modelList = new ArrayList<>();
db = this.getReadableDatabase();
String query = "SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + " ='" + selectSTRING + "'";
Cursor cursor = db.rawQuery(query, null);
//Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + "='" + str + "'" , null);
String newBACK = selectSTRING;
if (cursor.moveToFirst()) {
DBModel model = new DBModel();
while (!cursor.isAfterLast()) {
if (newBACK == selectSTRING) {
model.setRowid(cursor.getString(0));
model.setStation_Name(cursor.getString(1));
model.setDate_of_Purchase(cursor.getString(2));
model.setGas_Cost(cursor.getString(3));
modelList.add(model);
cursor.moveToNext();
}
}
}
int sz = modelList.size();
System.out.println("========= SIZE "+sz);
db.close();
return modelList;
}
现在我们使用intent转到DetailsActivity，这是失败
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
static List<DBModel> dbList;
static private Context context;
RecyclerAdapter(Context context, List<DBModel> dbList) {
RecyclerAdapter.dbList = new ArrayList<>();
RecyclerAdapter.context = context;
RecyclerAdapter.dbList = dbList;
}
@Override
public RecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_row, null);
// create ViewHolder
ViewHolder viewHolder = new ViewHolder(itemLayoutView);
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerAdapter.ViewHolder holder, int position) {
holder.rowid.setText(dbList.get(position).getRowid());
holder.station.setText(dbList.get(position).getStation_Name());
System.out.println("========== new position "+position);
}
@Override
public int getItemCount() {
return dbList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView station, rowid;
public ViewHolder(View itemLayoutView) {
super(itemLayoutView);
rowid = (TextView) itemLayoutView.findViewById(R.id.rvROWID);
station = (TextView) itemLayoutView.findViewById(R.id.rvSTATION);
// Attach a click listener to the entire row view
itemLayoutView.setOnClickListener(this);
}
@Override // When an item in DetailsActivity is touched (selected) the RecyclerView has
// a OnClickListener attached in the above Code that implements the method below
public void onClick(View v) {
System.out.println("======RowID "+rowid);
Intent intentN = new Intent(context, DetailsActivity.class);
Bundle extras = new Bundle();
extras.putInt("POSITION", getAdapterPosition());
extras.putString("FROM_LIST_ACTIVITY", "false");
///position = getAdapterPosition();
///position = getLayoutPosition();// Both work the same
intentN.putExtras(extras);
context.startActivity(intentN);
}
}
考虑从DBHelper发回数据，不知道如何在该类中编写Intent。这变成了意大利面条代码！
答案 0 :(得分：1)
这个问题的解决方案是开发人员在DBHelper中有多个搜索设计，每个搜索设计都由搜索活动中的不同按钮触发。此设计在DBHelper中导致多个ArrayLists都具有相同的名称，这使得RecycleAdapter疯狂，因为它是绑定到ArrayList所以OLD先生布尔要抢救！这是修改后的设计代码功能 在Search Activity中声明public static Boolean use = false; 和导入所需的导入静态com..MainActivity.use;
以下是每个搜索按钮的代码
public void findAllData(View view){
helper = new DBHelper(this);
helper.getDataFromDB();
use = false;
// Set Mr. Boolean
Intent intent = new Intent( MainActivity.this, ListActivity.class );
// ListActivity shows Results of the Search
startActivity( intent );
}
public void findSelect(View v){
selectSTRING = etFromDate.getText().toString();
// Get your Search variable
helper = new DBHelper(this);
helper.getDataFromDB();
etToDate.setText(sendBACK);
use = true;
Intent intent = new Intent( MainActivity.this, ListActivity.class );
startActivity( intent );
}
现在我们在DBHelper中进行所需的搜索
/* Retrive ALL data from database table named "TABLE_INFO" */
public List<DBModel> getDataFromDB(){
//String query = "SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + " > 0 " + " ORDER BY " + Col_ID + " DESC ";
/* Notice the SPACES before AND after the words WHERE ORDER BY ASC or DESC most of all the condition " > 0 "*/
/* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=*/
Cursor cursor = null;
List<DBModel> modelList = new ArrayList<>();
if(use == true){
String query = "SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + " ='" + selectSTRING + "'";
db = this.getWritableDatabase();
cursor = db.rawQuery(query,null);
}
if(use == false){
String query = "SELECT * FROM " + TABLE_INFO;
db = this.getWritableDatabase();
cursor = db.rawQuery(query,null);
}
if (cursor.moveToFirst()){
do {
DBModel model = new DBModel();
model.setRowid(cursor.getInt(0));
model.setStation_Name(cursor.getString(1));
model.setDate_of_Purchase(cursor.getString(2));
model.setGas_Cost(cursor.getString(3));
modelList.add(model);
int sz = modelList.size();
int out = model.setRowid(cursor.getInt(0));
String out1 = model.setStation_Name(cursor.getString(1));
String out2 = model.setDate_of_Purchase(cursor.getString(2));
String out3 = model.setGas_Cost(cursor.getString(3));
System.out.println("==============getDataFromDB ID "+out);
System.out.println("==============getDataFromDB Station "+out1);
System.out.println("==============getDataFromDB Date "+out2);
System.out.println("==============getDataFromDB Cost "+out3);
System.out.println("======= ======getDataFromDB SIZE "+sz);
}while (cursor.moveToNext());
}
db.close();
cursor.close();
return modelList;
}
唯一的失误是，如果按日期搜索并对数据库进行添加并跳回ListActivity，则不会显示新记录 我们正在努力这个Stay Tuned ha ha Good Job James_Duh
答案 1 :(得分：0)
您应该在此处设置OnClickListener：
@Override
public void onBindViewHolder(ReportAdapter.ViewHolderReport holder, int position) {
final Object object = objects.get(position);
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Do Something with the object at this position
}
});
}
代替您的ViewHolder，因为您不应该一次信任适配器位置。