從 Firebase 實時數據庫中檢索圖像

Question

如何從實時數據庫中檢索特定的 URL？

 final database = FirebaseDatabase(
    databaseURL:
    "https://trackkit-a5cf3-default-rtdb.asia-southeast1.firebasedatabase.app")
    .reference()
    .child('NTU')
    .child(widget.referenceName);

. . .

  Widget _buildItem(String imgPath, String labName, int quantity, String expiry,
  Function onAdd, Function onSubtract, Function onDelete) {
void _minusNum() {
  onSubtract();
}

void _onAdd() {
  onAdd();
}

void _onDelete() {
  onDelete();
}

return Padding(
    padding: const EdgeInsets.only(left: 0.0, right: 10, top: 0.0),
    child: Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: <Widget>[
        GestureDetector(
          onLongPress: _onDelete,
          child: Row(children: [
            Hero(
                tag: imgPath,
                child: const Image(
                    image: NetworkImage(''),  <---THIS IS THE LINE
                    fit: BoxFit.cover,
                    height: 120.0,
                    width: 130.0)),
            const SizedBox(width: 10.0),
            Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
              Text(
                labName,
                style: const TextStyle(
                  fontFamily: 'Montserrat',
                  fontSize: 12.0,
                  fontWeight: FontWeight.bold,
                ),
              ),
              Text(
                expiry,
                style: const TextStyle(
                  fontFamily: 'Montserrat',
                  fontSize: 12.0,
                  fontWeight: FontWeight.bold,
                ),
              ),
              Container(
                width: 100.0,
                height: 30.0,
                margin: const EdgeInsets.only(left: 0.0, top: 5.0),
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(17.0),
                    color: const Color(0xFF7A9BEE)),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: <Widget>[
                    InkWell(
                      onTap: _minusNum,
                      child: Container(
                        height: 25.0,
                        width: 25.0,
                        decoration: BoxDecoration(
                            borderRadius: BorderRadius.circular(7.0),
                            color: const Color(0xFF7A9BEE)),
                        child: const Center(
                          child: Icon(
                            Icons.remove,
                            color: Colors.white,
                            size: 20.0,
                          ),
                        ),
                      ),
                    ),
                    Text(quantity.toString(),
                        style: const TextStyle(
                            color: Colors.white,
                            fontFamily: 'Montserrat',
                            fontSize: 15.0)),
                    InkWell(
                      onTap: _onAdd,
                      child: Container(
                        height: 25.0,
                        width: 25.0,
                        decoration: BoxDecoration(
                            borderRadius: BorderRadius.circular(7.0),
                            color: Colors.white),
                        child: const Center(
                          child: Icon(
                            Icons.add,
                            color: Color(0xFF7A9BEE),
                            size: 20.0,
                          ),
                        ),
                      ),
                    ),
                  ],
                ),
              )
            ]),
          ]),
        ),
      ],
    ));

}

. . .

tag: imgPath,
                child: const Image(
                    image: NetworkImage(''),
                    fit: BoxFit.cover,
                    height: 120.0,
                    width: 130.0)

我能夠檢索 firebase 中項目的 rest，但我無法檢索圖像。

錯誤出現：

========圖片資源服務捕獲異常==================================== ============ 解析圖像編解碼器時拋出以下 ArgumentError：無效參數：URI 文件中未指定主機：///lists%5Bindex%5D%5B%22Image%22% 5D

Answer 1

這個問題不是很清楚，但是這個錯誤肯定會發生，因為你正在為你的NetworkImage分配一個無效的圖像鏈接'' 。