28 lines
843 B
Dart
28 lines
843 B
Dart
// 自定义物理效果 - 只允许下拉不允许上推
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import 'package:flutter/material.dart';
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class OnlyDownScrollPhysics extends ScrollPhysics {
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const OnlyDownScrollPhysics({super.parent});
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@override
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OnlyDownScrollPhysics applyTo(ScrollPhysics? ancestor) {
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return OnlyDownScrollPhysics(parent: buildParent(ancestor));
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}
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@override
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double applyBoundaryConditions(ScrollMetrics position, double value) {
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// 阻止向上滚动（当不在顶部时）
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if (value > position.pixels && position.pixels > position.minScrollExtent) {
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return value - position.pixels;
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}
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// 允许下拉刷新（当在顶部时下拉）
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if (value < position.pixels && position.pixels <= position.minScrollExtent) {
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return 0.0; // 允许下拉
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}
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return super.applyBoundaryConditions(position, value);
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}
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}
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