我想在调整窗口大小时调整图像大小。我想将此图像置于容器 div 元素的中心。我还想在 4 个边上填充。 (上/左/下/右:例如 15%)
现场演示:https://react-ts-f4jemk.stackblitz.io
现场编辑:https://stackblitz.com/edit/react-ts-f4jemk
它应该是这样的:
当窗口调整大小时,图像应该根据窗口大小变大或变小。在这种情况下,我想保持纵横比和顶部、左侧、底部和右侧的空白,以便图像可见并在 div 上居中。
到目前为止我尝试了什么:
updateDimensions() {
let imgHeight = this.state.imgHeight
let imgWidth = this.state.imgWidthMax
let w = window,
d = document,
documentElement = d.documentElement,
body = d.getElementsByTagName('body')[0],
width = w.innerWidth || documentElement.clientWidth || body.clientWidth,
height = w.innerHeight || documentElement.clientHeight || body.clientHeight
if (imgWidth && imgWidth > 0) {
imgWidth = imgWidth + width - this.state.width
imgHeight = imgHeight + height - this.state.height
const ratioW = width / imgWidth
const ratioH = height / imgHeight
this.setState({ width: width, height: height, imgHeight, imgWidth })
return
}
this.setState({ width: width, height: height, imgHeight, imgWidth })
}
componentWillMount() {
this.updateDimensions()
}
componentDidMount() {
window.addEventListener("resize", this.updateDimensions)
setTimeout(() => {
const imgHeight: number = this.imgEl.clientHeight
const imgWidth: number = this.imgEl.clientWidth
this.setState({ imgHeight, imgWidth, imgHeightMax: imgHeight, imgWidthMax: imgWidth })
}, 1000)
}
componentWillUnmount() {
window.removeEventListener("resize", this.updateDimensions)
}
我也尝试通过纯 CSS 来实现。但是,宽度或高度变得大于浏览器高度/宽度。
.img {
width: auto; // or 100%
height: 100%; // or auto
}
我的 updateDimensions()
有效,但是我的计算有误。我该如何正确处理这种情况?我怎样才能正确计算?
最佳答案
我更新了你的功能以根据图像的纵横比调整图像的大小
updateDimensions() {
let w = window,
d = document,
documentElement = d.documentElement,
body = d.getElementsByTagName("body")[0],
inner = d.querySelector(".inner");
//this calculates the padding %
const height = inner.clientHeight - inner.clientHeight * 0.15;
const width = inner.clientWidth - inner.clientWidth * 0.15;
let imgWidth = width;
//calculates hight base os aspect ratio
let imgHeight = (imgWidth * height) / width;
//if height is greater than the inner container, set the maximun size and recalculate width base on max-height
if (imgHeight > height) {
imgHeight = height;
imgWidth = (imgHeight * width) / height;
}
this.setState({ width, height, imgWidth, imgHeight });
}
这是在线编辑器上的更新代码:https://stackblitz.com/edit/react-ts-jbzynn?file=index.tsx
关于javascript - 在 React/TS 上调整窗口大小时调整图像大小、居中并保持纵横比,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56201733/