如何在Android中使用光标数据创建列表数组

Question

如何使用光标数据创建列表数组(滚动时列表显示第一个字母)？

Answer 1

浏览中的每个元素Cursor,然后将它们逐个添加到ArrayList.

ArrayList<WhateverTypeYouWant> mArrayList = new ArrayList<WhateverTypeYouWant>();
for(mCursor.moveToFirst(); !mCursor.isAfterLast(); mCursor.moveToNext()) {
    // The Cursor is now set to the right position
    mArrayList.add(mCursor.getWhateverTypeYouWant(WHATEVER_COLUMN_INDEX_YOU_WANT));
}

(替换WhateverTypeYouWant为您想要创建的任何类型ArrayList,以及WHATEVER_COLUMN_INDEX_YOU_WANT要从游标获取的值的列索引.)

Answer 2

一个快速更正:上面的for循环跳过光标的第一个元素.要包含第一个元素,请使用:

ArrayList<String> mArrayList = new ArrayList<String>();
mCursor.moveToFirst();
while(!mCursor.isAfterLast()) {
     mArrayList.add(mCursor.getString(mCursor.getColumnIndex(dbAdapter.KEY_NAME))); //add the item
     mCursor.moveToNext();
}

Answer 3

甚至比@ imbrizi更好的答案是:

ArrayList<String> mArrayList = new ArrayList<String>();
while(mCursor.moveToNext()) {
     mArrayList.add(mCursor.getString(mCursor.getColumnIndex(dbAdapter.KEY_NAME))); //add the item
}

moveToNext() 如果没有任何东西,它将返回false,因此这会使SLOC减少一些,并且更容易看到.

更好的方法是将列索引置于循环之外.

ArrayList<String> mArrayList = new ArrayList<String>();
int columnIndex=mCursor.getColumnIndex(dbAdapter.KEY_NAME)
while(mCursor.moveToNext()) {
     mArrayList.add(mCursor.getString(columnIndex)); //add the item
}