布局只是 main.xml，它在将新信息添加到 sqlite 数据库时显示多个 row.xml。单击按钮时，将显示带有数据的 AlertDialog。问题是，当我单击行中的按钮时，AlertDialog 正在从数据库中的下一条记录（下一行）获取数据（当我单击第一个按钮时，AD 正在获取第二条记录等），而不是从按钮所在的位置获取数据。我为按钮和 toast 消息设置标签，单击它时显示良好的 ID。MyCursorAdapter.java(...)@Overridepublic void bindView(View view, Context context, Cursor cursor) {TextView name = (TextView) view.findViewById(R.id.name);TextView id = (TextView) view.findViewById(R.id.id);TextView quantity = (TextView) view.findViewById(R.id.quantity);TextView mu = (TextView) view.findViewById(R.id.mu);Button bt = (Button) view.findViewById(R.id.rowalertdialog);CheckBox cb = (CheckBox)view.findViewById(R.id.checkboxmain2);name.setText(cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_NAME)));id.setText(cursor.getString(cursor.getColumnIndex(SQLiteAdapter._id)));quantity.setText(cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_QUANTITY)));mu.setText(cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_MU)));bt.setTag(cursor.getString(cursor.getColumnIndex(SQLiteAdapter._id)));cb.setChecked(cursor.getInt(cursor.getColumnIndex(SQLiteAdapter.KEY_CHECKED)) > 0);cb.setTag(cursor.getString(cursor.getColumnIndex(SQLiteAdapter._id)));}安卓SQLite.java(...)private void manageListView() {cursor = mySQLiteAdapter.queueAll();if(myadapter == null){ myadapter = new MyCursorAdapter(this,cursor); listContent.setAdapter(myadapter);}else { myadapter.swapCursor(cursor);}}
2 回答
PIPIONE
TA贡献1829条经验 获得超9个赞
工作示例
这是一个基于您之前的问题和这个问题的工作示例应用程序。
然而，
按钮单击处理，在不使用布局的onCLick（如 XML 中编码）的情况下进行处理，但在自定义CursorAdapter ( MyCursorAdapter.java ) 的bindView方法中设置。
它演示了 3 种获取与按钮关联的 id 的方法
item_id_fromcursor显示了如何从作为列表源的 Cursor 获取值（在本例中为该 id），该列表的位置应适当。
item_id_fromtag展示了如何从标签中获取 id（有些人不赞成这种技术）。
item_id_fromview展示了如何根据传递给按钮的视图从视图层次结构中获取值。
该处理允许删除和更新行（尽管更新非常基本，只是附加一个值而不是使用自定义对话框布局（您似乎掌握了这方面的知识））。
与前面的答案不同，还实现了处理添加的行（尽管值有限）。
生成的应用程序看起来像：-
A表示行已被删除（即 id 为 5-7 的行不存在）
B显示已更新的行（即已附加更新（如果更新更新则该行已更新两次））
C显示已添加的行。
如果单击编辑或删除按钮，则会出现对话框，例如：-
单击取消从对话框中返回，什么也不做。
单击删除将删除相应的行（如对话框消息中所述）。
单击 EDIT 通过附加更新的值来编辑名称（编辑已经编辑的行将添加进一步更新的行）
显然这可能不是所需的操作，它只是为了演示。
编码
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:id="@+id/panelup"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="LIST SQ1"
/>
<ListView
android:id="@+id/contentlist"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="@id/panelup"
android:layout_above="@id/paneldown"/>
<LinearLayout
android:id="@+id/paneldown"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true">
<EditText
android:id="@+id/name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
/>
<EditText
android:id="@+id/quantity"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="number"
android:layout_weight="2"
/>
<Spinner
android:id="@+id/mu"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:entries="@array/mu_values"
android:layout_weight="2"
/>
<Button
android:id="@+id/add"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="2"
android:text="+"
/>
</LinearLayout>
</LinearLayout>
行.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/layoutmain"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:padding="2dip"
android:text="M"/>
<TextView
android:id="@+id/id"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:padding="2dip"
android:paddingRight="10dip"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:padding="2dip"
android:paddingRight="10dip"
android:text="-" />
<TextView
android:id="@+id/name"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="2dip"/>
</LinearLayout>
<TextView
android:id="@+id/quantity"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="2dip"/>
<CheckBox
android:id="@+id/checkboxmain2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone"/>
<Button
android:id="@+id/editordelete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="EDIT or DELETE"/>
</LinearLayout>
注意 CheckBox 已隐藏
SQLiteHelper.java
public class SQLiteHelper extends SQLiteOpenHelper {
public static final String MYDATABASE_NAME = "mydatabase";
public static final int MYDATABASE_VERSION = 1;
public static final String MYDATABASE_TABLE = "mytable";
SQLiteDatabase mDB;
public SQLiteHelper(Context context, String name, SQLiteDatabase.CursorFactory factory,int version) {
super(context, name, factory, version);
mDB = this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
String crt_tbl_sql = "CREATE TABLE IF NOT EXISTS " + MYDATABASE_TABLE + "(" +
SQLiteAdapter._id + " INTEGER PRIMARY KEY, " +
SQLiteAdapter.KEY_NAME + " TEXT, " +
SQLiteAdapter.KEY_SHOP + " TEXT, " +
SQLiteAdapter.KEY_PDATE + " TEXT, " +
SQLiteAdapter.KEY_PRICE + " REAL, " +
SQLiteAdapter.KEY_QUANTITY + " INTEGER, " +
SQLiteAdapter.KEY_MU + " TEXT, " +
SQLiteAdapter.KEY_CHECKED + " INTEGER DEFAULT 0" +
")";
db.execSQL(crt_tbl_sql);
addSomeTestingData(db,10);
}
@Override
public void onConfigure(SQLiteDatabase db) {
super.onConfigure(db);
db.setForeignKeyConstraintsEnabled(true);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public long addRow(String name, String shop, String pdate, double price, int quantity, String mu, SQLiteDatabase db) {
ContentValues cv = new ContentValues();
cv.put(SQLiteAdapter.KEY_NAME,name);
cv.put(SQLiteAdapter.KEY_SHOP,shop);
cv.put(SQLiteAdapter.KEY_PDATE,pdate);
cv.put(SQLiteAdapter.KEY_PRICE,price);
cv.put(SQLiteAdapter.KEY_QUANTITY,quantity);
cv.put(SQLiteAdapter.KEY_MU,mu);
return db.insert(MYDATABASE_TABLE,null,cv);
}
private void addSomeTestingData(SQLiteDatabase db, int number_to_add) {
for (int i = 0; i < number_to_add;i++) {
String suffix = String.valueOf(i);
String day_in_month = suffix;
if (i < 10) {
day_in_month = "0" + day_in_month;
}
addRow(
"Test" + suffix,
"Shop" + suffix,
"2019-01-" + day_in_month,
10.5 + new Double(i * 3),
i * 4,
"mu" + suffix,
db
);
}
}
}
SQLiteAdapter.java
public class SQLiteAdapter {
SQLiteDatabase sqLiteDatabase;
SQLiteHelper sqLiteHelper;
Context context;
public static final String KEY_CHECKED = "checked";
public static final String _id = BaseColumns._ID;
public static final String KEY_NAME = "name";
public static final String KEY_QUANTITY = "quantity";
public static final String KEY_PRICE = "price";
public static final String KEY_MU = "mu";
public static final String KEY_PDATE = "pdate";
public static final String KEY_SHOP = "shop";
public SQLiteAdapter(Context context) {
this.context = context;
openToWrite();
}
public SQLiteAdapter openToWrite() throws android.database.SQLException {
sqLiteHelper = new SQLiteHelper(context, MYDATABASE_NAME, null,
MYDATABASE_VERSION);
sqLiteDatabase = sqLiteHelper.getWritableDatabase();
return this;
}
public void close() {
sqLiteHelper.close();
}
public long insertChecked(boolean data1) {
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_CHECKED, data1);
return sqLiteDatabase.insert(MYDATABASE_TABLE, null, contentValues);
}
public int updateChecked(long id,int check) {
ContentValues cv = new ContentValues();
cv.put(KEY_CHECKED,check);
String whereclause = _id + "=?";
String[] whereargs = new String[]{String.valueOf(id)};
return sqLiteDatabase.update(MYDATABASE_TABLE,cv,whereclause,whereargs);
}
public Cursor queueAll() {
String[] columns = new String[]{_id, KEY_NAME, KEY_PRICE,
KEY_QUANTITY, KEY_MU,
KEY_PDATE, KEY_SHOP, KEY_CHECKED};
Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns,
null, null, null, null, null);
return cursor;
}
public Cursor queueOneById(long id) {
String whereclause = _id + "=?";
String[] whereargs = new String[]{String.valueOf(id)};
String[] columns = new String[]{_id, KEY_NAME, KEY_PRICE,
KEY_QUANTITY, KEY_MU,
KEY_PDATE, KEY_SHOP, KEY_CHECKED};
return sqLiteDatabase.query(MYDATABASE_TABLE,columns,whereclause,whereargs,
null,null,null);
}
public int delete(long id) {
String whereclause = SQLiteAdapter._id + "=?";
String[] wherargs = new String[]{String.valueOf(id)};
return sqLiteDatabase.delete(MYDATABASE_TABLE,whereclause,wherargs);
}
public long updateById(long id, String column_to_change, String newvalue) {
ContentValues cv = new ContentValues();
cv.put(column_to_change,newvalue);
String whereclause = SQLiteAdapter._id + "=?";
String[] whereargs = new String[]{String.valueOf(id)};
return sqLiteDatabase.update(MYDATABASE_TABLE,cv,whereclause,whereargs);
}
}
增加了一些方法
MyCursorAdapter.java
public class MyCursorAdapter extends CursorAdapter {
SQLiteAdapter sqliteAdapter;
MyCursorAdapter thisCursorAdapter;
public MyCursorAdapter(Context context, Cursor c) {
super(context, c, true);
sqliteAdapter = new SQLiteAdapter(context);
thisCursorAdapter = this;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = super.getView(position, convertView, parent);
return v;
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return LayoutInflater.from(context).inflate(R.layout.row,parent,false);
}
@Override
public void bindView(View view, Context context, final Cursor cursor) {
//Note Cursor will be positioned appropriately
TextView name = (TextView) view.findViewById(R.id.name);
TextView id = (TextView) view.findViewById(R.id.id);
TextView quantity = (TextView) view.findViewById(R.id.quantity);
CheckBox cb = (CheckBox) view.findViewById(R.id.checkboxmain2);
Button eod = (Button) view.findViewById(R.id.editordelete);
name.setText(cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_NAME)));
id.setText(cursor.getString(cursor.getColumnIndex(SQLiteAdapter._id)));
quantity.setText(cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_QUANTITY)));
cb.setChecked(cursor.getInt(cursor.getColumnIndex(SQLiteAdapter.KEY_CHECKED)) > 0);
cb.setTag(cursor.getString(cursor.getColumnIndex(SQLiteAdapter._id))); //<<<<<<<<<< SET TAG to the ID
eod.setTag(cursor.getString(cursor.getColumnIndex(SQLiteAdapter._id)));
// dynamically add the listeners as opposed to coding onCLick in layout XML
eod.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// get the id from the id TextView, within the view hierarchy rather than from the buttons tag
// NOTE assumes the Button's parent is a LinearLayout (for simplicity)
// This in theory is the recommended way rather than setting the tag
LinearLayout ll = (LinearLayout) v.getParent();
TextView id = ll.findViewById(R.id.id), name = ll.findViewById(R.id.name);
final long item_id_fromview = Long.valueOf(id.getText().toString());
final String item_name = name.getText().toString();
// get the id from the tag
long item_id_fromtag = Long.valueOf(v.getTag().toString());
// get the if from the cursor that is the source of the Listview, it should be positioned accordingly
long item_id_fromcursor = cursor.getLong(cursor.getColumnIndex(SQLiteAdapter._id));
// Show both
Toast.makeText(v.getContext(),
"The id (from the view hierarchy) is " + String.valueOf(item_id_fromview) +
" or (from the tag) is " + String.valueOf(item_id_fromtag) +
" or (from the cursor) is" + String.valueOf(item_id_fromcursor)
, Toast.LENGTH_SHORT).show();
AlertDialog.Builder mydialog = new AlertDialog.Builder(v.getContext());
mydialog.setMessage("EDIT or DELETE Row:- ID: " + String.valueOf(item_id_fromview) + "Name: " + item_name);
mydialog.setPositiveButton("DELETE", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
sqliteAdapter.delete(item_id_fromview);
refreshList();
}
});
mydialog.setNeutralButton("EDIT", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
sqliteAdapter.updateById(item_id_fromview,SQLiteAdapter.KEY_NAME,item_name + " Updated");
refreshList();
}
});
mydialog.setNegativeButton("CANCEL", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
mydialog.show();
}
});
}
private void refreshList() {
thisCursorAdapter.swapCursor(sqliteAdapter.queueAll());
thisCursorAdapter.notifyDataSetChanged();
}
}
查看绑定视图时如何设置 onCLickListener
查看获取id的 3 种不同方法
请参阅类似于 AndroidSQLite 活动中使用的 ManageListView 方法的 refreshList 方法。
AndroidSQlite.java（活动）
public class AndroidSQLite extends AppCompatActivity {
ListView listContent;
Button buttonAdd;
Cursor cursor;
SQLiteAdapter mySQLiteAdapter;
EditText name, quantity;
Spinner mu;
//SimpleCursorAdapter cursorAdapter; //<<<<<<<<<< NOT USED ANYMORE
MyCursorAdapter myadapter; //<<<<<<<<<< Use a custom adapter that sets the tag of the checkbox to the respective id
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listContent = (ListView) findViewById(R.id.contentlist);
name = (EditText) findViewById(R.id.name);
quantity = (EditText) findViewById(R.id.quantity);
buttonAdd = (Button) findViewById(R.id.add);
mu = (Spinner) findViewById(R.id.mu);
handleAddButton();
mySQLiteAdapter = new SQLiteAdapter(this);
mySQLiteAdapter.openToWrite();
manageListView(); //<<<<<<<<<< ADDED
}
//<<<<<<<<<< ADDED >>>>>>>>>>
@Override
protected void onResume() {
super.onResume();
manageListView(); //Refresh the List when resuming e.g. returning from another activity
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
cursor.close(); //<<<<<<<<<< SHOULD ALWAYS CLOSE CURSOR
mySQLiteAdapter.close();
}
private void handleAddButton() {
buttonAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if ((name.getText().toString()).length() < 1) {
Toast.makeText(v.getContext(),"Name cannot be empty",Toast.LENGTH_SHORT).show();
name.requestFocus();
return;
}
if ((quantity.getText().toString()).length() < 1) {
Toast.makeText(v.getContext(),"Quantity cannot be empty",Toast.LENGTH_SHORT).show();
quantity.requestFocus();
return;
}
mySQLiteAdapter.sqLiteHelper.addRow(
name.getText().toString(),
// Arbritary values for testing
"2019-01-01",
"The Shop",
100.33,
Integer.valueOf(quantity.getText().toString()),
mu.getSelectedItem().toString(),
mySQLiteAdapter.sqLiteDatabase
);
manageListView();
}
});
}
private void manageListView() {
cursor = mySQLiteAdapter.queueAll(); // get the source data (cursor) for the listview
if (myadapter == null) {
myadapter = new MyCursorAdapter(this,cursor);
listContent.setAdapter(myadapter);
} else {
myadapter.swapCursor(cursor);
}
}
}
慕工程0101907
TA贡献1887条经验 获得超5个赞
Cursor cursor = (Cursor) parent.getItemAtPosition(id); 将根据它在列表中的位置获取项目，但您使用的是 id（从按钮的标签中提取）作为它的位置。这将很少是正确的。
列表中的第一个位置是 0，第一个 id 将是 1（假设没有删除任何行并且您没有手动设置 id），因此您报告的症状。
如果行已被删除，那么每个缺失的 id 都会增加 id 和 position 之间的差异。如果行按 id 以外的任何其他顺序排序，则位置 v id 可能会出路。如果 where 子句不包括行，那么 id 和位置也会有所不同。
简单的事实是您不能依赖 id 和列表中的位置之间的任何关系。
您可以做的是使用标签中的 id 来查询数据库以提取特定行。该查询将与用于获取列表光标的查询相同，只是它将使用第三个 ( SQLiteAdapter._id + "=?") 和第四个参数 ( new String[]{String.valueOf(id)}) （如果使用查询便利方法）。
注释已更正（缺少S添加到 QLiteAdapter），因为评论。
已修改
我尝试添加我在上一条评论中写的代码，但这是错误的。我不知道如何实施您的更改。–
您的代码可能是：-
public void ListViewButtonHandler(View v){
Button bt = v.findViewById(R.id.rowalertdialog);
Toast.makeText(this, "You clicked the Button for ID " + (String)bt.getTag(), Toast.LENGTH_SHORT).show(); //TODO not needed
int id = Integer.valueOf((String) bt.getTag());
ListView parent = (ListView)findViewById(R.id.contentlist); //<<<<<<<<<< NOT NEEDED (I think)
String whereclause = SQLiteAdapter._id _ "=?"; //<<<<<<<<<< ADDED
String[] whereargs = new String[]{bt.getTag()}; //<<<<<<<<<< ADDED
Cursor cursor = mySQLiteAdapter.getWitableDatabase().query(SQLiteAdapter.MYDATABASE_TABLE,null,whereclause,whereargs,null,null,null); //<<<<<<<<<< ADDED
//Cursor cursor = (Cursor) parent.getItemAtPosition(id); //<<<<<<<<<< REMOVED/COMMENTED OUT
//<<<<<<<<<<< ADDED to move to the extracted row, will toast if no such row
if (!cursor.moveToFirst) {
Toast.makeText(this, "Unable to retrieve row for ID " + (String)bt.getTag(), Toast.LENGTH_SHORT).show();
return;
}
final int item_id = cursor.getInt(cursor.getColumnIndex(SQLiteAdapter._id));
String item_name = cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_NAME));
String item_quantity = cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_QUANTITY))
cursor.close(); //<<<<<<<<<< ADDED should always close a cursor when done with it
.......... the rest of the code
请注意评论
请注意，您可能需要将SQLiteAdapter.MYDATABASE_TABLE更改为适当的值。
注意上面的代码是in-principal code，它没有经过测试或运行，因此可能有一些错误
选择
如果您将以下方法（基于上一个问题）添加到 SQLiteAdapter.java ：-
public Cursor queueOneById(long id) {
String whereclause = _id + "=?";
String[] whereargs = new String[]{String.valueOf(id)};
String[] columns = new String[]{_id, KEY_NAME, KEY_PRICE,
KEY_QUANTITY, KEY_MU,
KEY_PDATE, KEY_SHOP, KEY_CHECKED};
return sqLiteDatabase.query(MYDATABASE_TABLE,columns,whereclause,whereargs,
null,null,null);
}
然后你可以改变
Cursor cursor = mySQLiteAdapter.getWitableDatabase().query(SQLiteAdapter.MYDATABASE_TABLE,null,whereclause,whereargs,null,null,null);
至
Cursor cursor = mySQLiteAdapter.queueOneById(id);
请注意，这仍然需要上述其他更改。那就是你需要:-
if (!cursor.moveToFirst) { Toast.makeText(this, "无法检索 ID 行" + (String)bt.getTag(), Toast.LENGTH_SHORT).show(); 返回; }
没有上面的代码。光标将位于位置-1（在第一行之前）。所以cursor.moveToFirst需要定位到提取的行（应该只有一行）。如果没有行，则 moveToFirst 将返回 false（无法完成移动）并且将发出 Toast，然后 onClick 方法将返回。
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