uniapp/app 截屏并裁剪指定比例

 涉及到的api 

uni.createCanvasContext(canvasId, this);  画布api

getCurrentPages(); 获取当前页面实例api 

page.$getAppWebview().draw   

截屏绘制 将Webview窗口的可视区域截屏并绘制到Bitmap图片对象中。

参考: HTML5+ API Reference

screenshot(canvasId, clip = {}) {
		// #ifdef APP-PLUS
		const ctx = uni.createCanvasContext(canvasId, this);
		var pages = getCurrentPages(); //获取当前页面信息
		var page = pages[pages.length - 1];
		var bitmap = null;
		var currentWebview = page.$getAppWebview();
		bitmap = new plus.nativeObj.Bitmap('amway_img');
		let that = this
		// 将webview内容绘制到Bitmap对象中
		currentWebview.draw(bitmap, () => {
			// console.log('截屏绘制图片成功');
			let rand = Math.floor(Math.random() * 10000)
			let saveUrl = '_doc/' + rand + 'share.jpg';
			bitmap.save(saveUrl, {}, (i) => {
				uni.saveImageToPhotosAlbum({
					filePath: i.target,
					success: function() {
						uni.showToast({
							title: '保存图片成功',
							mask: false,
							duration: 1500
						});
					}
				})
			})
		}, (err) => {
			console.log(err)
		}, {
			clip
		})
		// #endif
	},