HTML5 Canvas 隐藏和显示图形教程

要使用 Konva 隐藏和显示图形，可以在实例化图形时设置 visible 属性，也可以使用 hide() 和 show() 方法。

**操作说明：**单击按钮以显示或隐藏图形。

Vanilla

import Konva from 'konva';

const stage = new Konva.Stage({
  container: 'container',
  width: window.innerWidth,
  height: window.innerHeight,
});

const layer = new Konva.Layer();
stage.add(layer);

const rect = new Konva.Rect({
  x: stage.width() / 2 - 50,
  y: stage.height() / 2 - 25,
  width: 100,
  height: 50,
  fill: 'green',
  stroke: 'black',
  strokeWidth: 4,
});
layer.add(rect);

// update button creation and styling
const buttonContainer = document.createElement('div');
buttonContainer.style.position = 'absolute';
buttonContainer.style.zIndex = 1;
buttonContainer.style.padding = '10px';
buttonContainer.style.top = '0px';
buttonContainer.style.left = '0px';

const showBtn = document.createElement('button');
showBtn.textContent = 'Show';
showBtn.onclick = () => rect.show();
buttonContainer.appendChild(showBtn);

const hideBtn = document.createElement('button');
hideBtn.textContent = 'Hide';
hideBtn.onclick = () => rect.hide();
buttonContainer.appendChild(hideBtn);

document.body.appendChild(buttonContainer);

React

import React, { useState } from 'react';
import { Stage, Layer, Rect } from 'react-konva';

function App() {
  const [visible, setVisible] = useState(true);

  return (
    <div style={{ position: 'relative' }}>
      <div style={{ position: 'absolute', zIndex: 1, padding: '10px' }}>
        <button onClick={() => setVisible(true)}>Show</button>
        <button onClick={() => setVisible(false)}>Hide</button>
      </div>
      <Stage width={window.innerWidth} height={window.innerHeight}>
        <Layer>
          <Rect
            x={window.innerWidth / 2 - 50}
            y={window.innerHeight / 2 - 25}
            width={100}
            height={50}
            fill="green"
            stroke="black"
            strokeWidth={4}
            visible={visible}
          />
        </Layer>
      </Stage>
    </div>
  );
}

export default App;

Vue

<template>
  <div style="position: relative;">
    <div style="position: absolute; z-index: 1; padding: 10px;">
      <button @click="showShape">Show</button>
      <button @click="hideShape">Hide</button>
    </div>
    <v-stage :config="stageSize">
      <v-layer>
        <v-rect :config="rectConfig"/>
      </v-layer>
    </v-stage>
  </div>
</template>

<script setup>
import { ref } from 'vue';

const stageSize = {
  width: window.innerWidth,
  height: window.innerHeight
};

const visible = ref(true);

const rectConfig = {
  x: window.innerWidth / 2 - 50,
  y: window.innerHeight / 2 - 25,
  width: 100,
  height: 50,
  fill: 'green',
  stroke: 'black',
  strokeWidth: 4,
  visible: visible.value
};

const showShape = () => {
  visible.value = true;
  rectConfig.visible = true;
};

const hideShape = () => {
  visible.value = false;
  rectConfig.visible = false;
};
</script>