Java 无法从sqlite数据库填充spineer
我无法从sqlite db填充微调器。有人能帮我吗 以下是我的代码 LoginDatabaseAdapter.javaJava 无法从sqlite数据库填充spineer,java,android,sqlite,Java,Android,Sqlite,我无法从sqlite db填充微调器。有人能帮我吗 以下是我的代码 LoginDatabaseAdapter.java public List<String> GetAllLabels(){ List<String> labels = new ArrayList<String>(); try { String selectQuery = "SELECT ID,category FROM CategoryMaster";
public List<String> GetAllLabels(){
List<String> labels = new ArrayList<String>();
try
{
String selectQuery = "SELECT ID,category FROM CategoryMaster";
SQLiteDatabase db = this.getDatabaseInstance();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
labels.add(cursor.getString(1));
} while (cursor.moveToNext());
}
// closing connection
cursor.close();
}
catch(Exception e)
{
String StackTrace=Log.getStackTraceString(e);
Toast.makeText(context,lineno+StackTrace,Toast.LENGTH_LONG).show();
}
// returning lables
return labels;
}
}
private void loadSpinnerData()
{
try
{
LoginDataBaseAdapter db = new LoginDataBaseAdapter(getApplicationContext());
List<String> lables = db.GetAllLabels();
// Creating adapter for spinner
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, lables);
// Drop down layout style - list view with radio button
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// attaching data adapter to spinner
Spinnercategory.setAdapter(dataAdapter);
}
catch(Exception e)
{
String stackTrace = Log.getStackTraceString(e);
Toast.makeText(getApplicationContext(), stackTrace, Toast.LENGTH_LONG).show();
}
}
公共列表GetAllLabels(){
列表标签=新的ArrayList();
尝试
{
String selectQuery=“从CategoryMaster中选择ID、类别”;
SQLiteDatabase db=this.getDatabaseInstance();
Cursor Cursor=db.rawQuery(selectQuery,null);
//循环遍历所有行并添加到列表
if(cursor.moveToFirst()){
做{
labels.add(cursor.getString(1));
}while(cursor.moveToNext());
}
//闭合连接
cursor.close();
}
捕获(例外e)
{
字符串StackTrace=Log.getStackTraceString(e);
Toast.makeText(context,lineno+StackTrace,Toast.LENGTH_LONG).show();
}
//退回标签
退货标签;
}
}
AddProduct.java
public List<String> GetAllLabels(){
List<String> labels = new ArrayList<String>();
try
{
String selectQuery = "SELECT ID,category FROM CategoryMaster";
SQLiteDatabase db = this.getDatabaseInstance();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
labels.add(cursor.getString(1));
} while (cursor.moveToNext());
}
// closing connection
cursor.close();
}
catch(Exception e)
{
String StackTrace=Log.getStackTraceString(e);
Toast.makeText(context,lineno+StackTrace,Toast.LENGTH_LONG).show();
}
// returning lables
return labels;
}
}
private void loadSpinnerData()
{
try
{
LoginDataBaseAdapter db = new LoginDataBaseAdapter(getApplicationContext());
List<String> lables = db.GetAllLabels();
// Creating adapter for spinner
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, lables);
// Drop down layout style - list view with radio button
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// attaching data adapter to spinner
Spinnercategory.setAdapter(dataAdapter);
}
catch(Exception e)
{
String stackTrace = Log.getStackTraceString(e);
Toast.makeText(getApplicationContext(), stackTrace, Toast.LENGTH_LONG).show();
}
}
private void loadSpinnerData()
{
尝试
{
LoginDataBaseAdapter db=新的LoginDataBaseAdapter(getApplicationContext());
列表标签=db.GetAllLabels();
//为微调器创建适配器
ArrayAdapter dataAdapter=新的ArrayAdapter(这是android.R.layout.simple\u微调器\u项,标签);
//下拉式布局样式-带单选按钮的列表视图
dataAdapter.setDropDownViewResource(android.R.layout.simple\u微调器\u下拉项);
//将数据适配器连接到微调器
喷丝头类别。setAdapter(数据适配器);
}
捕获(例外e)
{
字符串stackTrace=Log.getStackTraceString(e);
Toast.makeText(getApplicationContext(),stackTrace,Toast.LENGTH_LONG.show();
}
}
在我在loadSpinnerData()中声明spinner并获取spinner之后,请提前感谢您。之后,我可以在spinner中填充项目了。您的日志说明了什么?错误?确保已创建数据库类实例。还要检查您的查询是否有效,执行一些System.out.println();对于光标返回的字符串,您可以在logcat上看到输出。我使用toast.my logcat进行了测试,没有显示任何错误。我在以下行中遇到问题ArrayAdapter dataAdapter=new ArrayAdapter(这个,android.R.layout.simple_spinner_项,标签);//下拉布局样式-带有单选按钮dataAdapter.setDropDownViewResource(android.R.layout.simple_微调器_下拉项)的列表视图;//将数据适配器连接到spinner Spinnercategory.setAdapter(数据适配器);