如何在反應中獲得正確的畫布寬度和高度？

Question

我正在嘗試在React中使用canvas。 以下代碼應該給我黑色的800x800畫布，但是由於某種原因，它會忽略我的尺寸並顯示300x150的畫布。

import React, {Component} from "react";

class Sample extends Component {

    state = {
        canvasWidth: 800,
        canvasHeight: 800
    }
    canvasRef = React.createRef();

    componentDidMount() {
        const canvas = this.canvasRef.current;
        const context = canvas.getContext('2d');
        context.fillRect(0, 0, this.state.canvasWidth, this.state.canvasHeight);
    }

    render() {
        return (
            <div>
                <canvas ref={this.canvasRef} />
            </div>
        );
    }
}

export default Sample

Answer 1

您需要將width和height設置為html屬性：

   <canvas ref={this.canvasRef} width={this.state.canvasWidth} height={this.state.canvasHeight}/>