好吧，这很烦人，但是我已经很久了。该按钮没有更新值
这是光标适配器类，我知道这是很多代码，但是在我声明按钮后，您只需要查看绑定视图即可。我给了整个代码，以防其他人实施其他事情 -
`公共类FruitsFragmentCursorAdapter扩展了Cursoradapter {
public FruitsFragmentCursorAdapter(Context context, Cursor cursor) {
super(context,cursor,0);
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return LayoutInflater.from(context).inflate(R.layout.fragment_fruits,parent,false);
}
@Override
public void bindView(View view, final Context context, final Cursor cursor) {
//final
//First find all the views that I want to modify individually
ImageView imageView = (ImageView) view.findViewById(R.id.fruit_fragment_fruit_image);
TextView engTextView = (TextView) view.findViewById(R.id.fruit_fragment_english_name);
TextView hindiTextView = (TextView) view.findViewById(R.id.fruit_fragment_hindi_name);
TextView measureTextView = (TextView) view.findViewById(R.id.fruit_fragment_unit_measure);
TextView priceTextView = (TextView) view.findViewById(R.id.fruit_fragment_unit_price);
final TextView quantityTextView = (TextView) view.findViewById(R.id.fruit_fragment_quantity_text_view);
TextView priceCalTextView = (TextView) view.findViewById(R.id.fruit_fragment_price_calculation);
//Find the columns of the attributes we are interested in
int columnImage = cursor.getColumnIndex(itemsSoldContractEntry.COLUMN_IMAGE);
int columnEngName = cursor.getColumnIndex(itemsSoldContractEntry.COLUMN_ITEM_NAME_ENGLISH);
int columnHinName = cursor.getColumnIndex(itemsSoldContractEntry.COLUMN_ITEM_NAME_HINDI);
int columnMeasure = cursor.getColumnIndex(itemsSoldContractEntry.COLUMN_MEASURE);
int columnPrice = cursor.getColumnIndex(itemsSoldContractEntry.COLUMN_UNIT_PRICE);
final int columnQuantity = cursor.getColumnIndex(itemsSoldContractEntry.COLUMN_QUANTITY);
final int columnItemSoldID = cursor.getColumnIndex(itemsSoldContractEntry.COLUMN_ITEM_ID);
final int columnID = cursor.getColumnIndex(itemsSoldContractEntry._ID);
//Read the attributes from the cursor
final String image = cursor.getString(columnImage);
final String engName = cursor.getString(columnEngName);
String hinName = cursor.getString(columnHinName);
String measure = cursor.getString(columnMeasure);
String price = cursor.getString(columnPrice);
String quantity = cursor.getString(columnQuantity);
//get the string for the cal text view separately
String calculation = quantity + " x "+price + " = " + Integer.parseInt(quantity)*Integer.parseInt(price);
//Decode the string to create a bitmap
byte[] decodedString = Base64.decode(image,Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString,0,decodedString.length);
//Update the text views with the values
imageView.setImageBitmap(decodedByte);
engTextView.setText(engName);
hindiTextView.setText(hinName);
measureTextView.setText("per "+measure);
priceTextView.setText("₹ " + price);
quantityTextView.setText(quantity);
priceCalTextView.setText(calculation);
//Define the two buttons (increment and decrement)
Button incrementsButton = (Button) view.findViewById(R.id.fruit_fragment_increment);
//Get the position of the cursor
final int position = cursor.getPosition();
//Set the onclick listener
incrementsButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Set up a content values object to hold the quantity when updated
ContentValues incrementValue = new ContentValues();
//Move the cursor to the position of the current item under operation
cursor.moveToPosition(position);
//Update the quantity value
int oldQuantity = (cursor.getInt(columnQuantity));
int newQuantity = oldQuantity +1;
//Works till here
//Put the value in the content values
incrementValue.put(itemsSoldContractEntry.COLUMN_QUANTITY,newQuantity);
//Selection claus which will point to the item_sold_id which will be updated
String selection = itemsSoldContractEntry._ID + "=?";
//Get the item id which should be updated
int item_id = cursor.getInt(columnID);
String itemIDArgs = Integer.toString(item_id);
//Works till here
//Selection args claus
String[] selectionArgs = {itemIDArgs};
//Update the value
int something = context.getContentResolver().update(itemsSoldContractEntry.CONTENT_URI_ITEMS_SOLD,incrementValue,selection,selectionArgs);
Log.v("Updated"," Row"+ something);
//This is a toast to check if the correct item is being clicked
Toast.makeText(context,something+"",Toast.LENGTH_SHORT).show();
//New quantity
String newQu = cursor.getString(columnQuantity);
quantityTextView.setText(newQu);
}
});
}
}
每次我单击按钮时，都不会更新。我不知道为什么。我已经浏览了Google的所有文档，并搜寻了Stackoverflow。仍然不知道。它一直返回0。在评论中，我添加了直到其有效的部分。请帮助。
弄清楚了。如果您注意到，我使用URI访问数据库。我意识到URI没有配置为处理更新，因此返回0(已更新的行数(。一旦解决了，这很简单。使用修复 -
附加代码 //Move the cursor to the position of the current item under operation
cursor.moveToPosition(position);
//Update the quantity value
int oldQuantity = (cursor.getInt(columnQuantity));
int newQuantity = oldQuantity +1;
//Works till here
//Put the value in the content values
incrementValue.put(itemsSoldContractEntry.COLUMN_QUANTITY,newQuantity);
//Selection claus which will point to the item_sold_id which will be updated
String selection = itemsSoldContractEntry._ID + "=?";
//Get the item id which should be updated
int item_id = cursor.getInt(columnID);
String itemIDArgs = Integer.toString(item_id);
//This is a toast to check if the correct item is being clicked
Toast.makeText(context,itemIDArgs+"",Toast.LENGTH_SHORT).show();
//Works till here
//Selection args claus
String[] selectionArgs = {itemIDArgs};
//Update the value
int something = context.getContentResolver().update(
Uri.withAppendedPath(itemsSoldContractEntry.CONTENT_URI_ITEMS_SOLD,Integer.toString(item_id)),
incrementValue,
selection,selectionArgs);
注意 - 我的内容提供商具有仅写入一行而不是整个表的功能，因此，如果您注意到我已经在我更新数量的代码末端附加了ID。