com.kasite.client.uniapp.patient/pagesNetHos/st1/static/js/imgCompress.ts

/**
 *
 *
 *      图片压缩
 *
 *
 */

/**
 * 给的文件资源是否小于LimitSize （M）, 小于走lessCallBack， 大于走moreCallBack
 */
export function imageSizeIsLessLimitSize(
	imagePath: string,
	limitSize: number,
	lessCallBack: () => void,
	moreCallBack: () => void
): void {
	uni.getFileInfo({
		filePath: imagePath,
		success(res) {
			console.log("压缩前图片大小:", res.size / 1024, 'kb');
			if (res.size > 1024 * 1024 * limitSize) {
				moreCallBack();
			} else {
				lessCallBack();
			}
		}
	});
}

// 主调用方法

/**
 * 获取小于限制大小的Image, limitSize默认为1M，递归调用。
 */
export function getLessLimitSizeImage(
	canvasId: string,
	imagePath: string,
	limitSize: number = 1,
	drawWidth: number,
	callBack: (path: string) => void
): void {
	imageSizeIsLessLimitSize(imagePath, limitSize,
		() => {
			callBack(imagePath);
		},
		() => {
			uni.getImageInfo({
				src: imagePath,
				success: function (imageInfo) {
					var maxSide = Math.max(imageInfo.width, imageInfo.height);
					//画板的宽高默认是windowWidth
					var windowW = drawWidth;
					var scale = 1;
					if (maxSide > windowW) {
						scale = windowW / maxSide;
					}
					var imageW = Math.floor(imageInfo.width * scale);
					var imageH = Math.floor(imageInfo.height * scale);
					console.log('调用压缩', imageW, imageH);
					getCanvasImage(canvasId, imagePath, imageW, imageH,
						(pressImgPath: string) => {
							getLessLimitSizeImage(canvasId, pressImgPath, limitSize, drawWidth * 0.7, callBack);
						}
					);
				}
			});
		}
	);
}

/**
 * 获取画布图片
 */
function getCanvasImage(
	canvasId: string,
	imagePath: string,
	imageW: number,
	imageH: number,
	getImgsuccess: (path: string) => void
): void {
	// TODO: UniApp 中 canvas 的使用方式与微信小程序不同，需要根据实际情况调整
	// const ctx = uni.createCanvasContext(canvasId);
	// ctx.drawImage(imagePath, 0, 0, imageW, imageH);
	// ctx.draw(false, () => {
	//   uni.canvasToTempFilePath({
	//     canvasId: canvasId,
	//     x: 0,
	//     y: 0,
	//     width: imageW,
	//     height: imageH,
	//     quality: 1,
	//     success(res) {
	//       getImgsuccess(res.tempFilePath);
	//     }
	//   });
	// });
	console.warn('getCanvasImage 需要根据 UniApp 的 canvas API 进行调整');
}