如何在Flutter中獲取GestureDetector的x和y軸坐標

目前，我正在構建一個 Pinterest 克隆應用程式，我真的需要你的幫助。實際上，我花了將近一個小時來尋找答案，但給出的解決方案都沒有奏效。所以我需要的只是確定用戶通過手勢檢測器按下位置的 x 和 y 軸。任何人都可以幫助我，請...

uj5u.com熱心網友回復：

你的問題不清楚。你是什??么意思determine the x and y axes of the Gesture detector

如果您只需要知道用戶是否向右、向左或向下滑動，這里是一個示例

  GestureDetector(
          onVerticalDragUpdate: (details) {
    int sensitivity = 8;
            if (details.delta.dy > sensitivity) {
              // Down Swipe
              
            } else if (details.delta.dy < -sensitivity) {
              // Up Swipe
             
            }
          },
          onHorizontalDragUpdate: (details) {
            // Note: Sensitivity is integer used when you don't want to mess up vertical drag
            int sensitivity = 8;
            if (details.delta.dx > sensitivity) {
              // Right Swipe
             
            } else if (details.delta.dx < -sensitivity) {
             
              //Left Swipe
            }
          },

uj5u.com熱心網友回復：

您可以根據需要使用rect_getter。并執行如下：

    var globalKey = RectGetter.createGlobalKey();
  Offset _tapPosition;
  var dx;   //for x-axis
  var dy;   //for y-axis

RectGetter(
              key: globalKey,
              child: new Expanded(
                child: new InkWell(
                  onTap:  _handleTapDown,
                  onTapDown: _handleTapDown,
                  child: Center(
                    child: Container(
                      child: Utility.imageFromBase64String(imagename),
                      //  backgroundColor: const Color(0xFF20283e),
                    ),
                  ),
                ),
              ),
            ),

_handleTapDown 函式

void _handleTapDown(TapDownDetails details) {
final RenderBox referenceBox = context.findRenderObject();
setState(() {
  _tapPosition = referenceBox.globalToLocal(details.globalPosition);
  dx = double.parse(_tapPosition.dx.toStringAsFixed(2));
  dy = double.parse(_tapPosition.dy.toStringAsFixed(2));
  print(_tapPosition);
 
});
}

uj5u.com熱心網友回復：

我相信您不應該在GestureDetector這里使用，而是使用Listener小部件。作為偵聽器，您可以為您提供用戶按下位置的全域位置，或者與按下的小部件開始位置的相對位置。

這是一些示例代碼：

import 'package:flutter/material.dart';

class GetPositionExample extends StatelessWidget {
  const GetPositionExample({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Listener(

      // This will report a PointerDownEvent whenever the user presses the screen.
      // If you want updates as the user moves their finger across the screen,
      // use onPointerMove instead.
      onPointerDown: (PointerDownEvent event) {
        // Global screen position.
        print("Global position x:${event.position.dx}, y:${event.position.dy}");
        // Position relative to where this widget starts.
        print("Relative position: x:${event.localPosition.dx}, y:${event.localPosition.dy}");
      },

      // You should also be aware of these Listener methods,
      // if any of them is more suited for your use-case:

      // onPointerMove: (PointerMoveEvent event) {},
      // onPointerUp: (PointerUpEvent event) {},
      // onPointerCancel: (PointerCancelEvent event) {},
      // onPointerHover: (PointerHoverEvent event) {},
      // onPointerSignal: (PointerSignalEvent event) {},

      child: Container(
        color: Colors.blue,
        width: MediaQuery.of(context).size.width,
        height: MediaQuery.of(context).size.height/2,
      ),
    );
  }
}

// Some code to run the above example
class App extends StatelessWidget {
  const App({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(home: Scaffold(body: Column(
      mainAxisAlignment: MainAxisAlignment.end,
      children: const [
        GetPositionExample(),
      ],
    )));
  }
}

void main() => runApp(const App());

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