uniapp图片添加水印

直接上代码

<template>
	<view class="inspection">
		<view class="inspection_details">
			<view class="upload public" @click="uploadFile">
				<text>上传图片</text>
				<text class="upload_icon">+</text>
			</view>
			<canvas canvas-id="waterMarkCanvas" style="width: 500rpx; height: 500rpx;" />
		</view>
		<view class="submit">
			<text class="submit_btn" @click="submit">提交</text>
		</view>
	</view>
</template>
<script>
	export default {
		data() {
			return {
				cvHeight: 0,
				cvWidth: 0,
				canvasImg: undefined,
				canvasWidth: 0,
				canvasHeight: 0
			};
		},
		methods: {
			uploadFile() {
				let that = this;
				uni.chooseImage({
					count: 1,
					sourceType: ['album'],
					success: function(res) {
						uni.getImageInfo({
							src: res.tempFilePaths[0],
							success: function(image) {
								const ctx = uni.createCanvasContext('waterMarkCanvas')
								console.log(image.width);
								console.log(image.height);
								console.log('详情', image);
								const canvasWidth = uni.upx2px(300); // 500rpx转px
								const canvasHeight = uni.upx2px(500);
								ctx.drawImage(image.path, 0, 0, canvasWidth, canvasHeight);
								ctx.setFontSize(16);
								ctx.setFillStyle('red');
								const watermarkText = '测试';
								ctx.fillText(watermarkText, 10, canvasHeight - 10);
								ctx.draw(true)
								
								setTimeout(() => {
									uni.canvasToTempFilePath({
										canvasId: 'waterMarkCanvas',
										fileType: "jpg",
										width: canvasWidth,
										height: canvasHeight,
										destWidth: canvasWidth,
										destHeight: canvasHeight,
										success: (res) => {
											console.log('水印生成：', res);
											console.log(res.tempFilePath);
											that.canvasImg = res.tempFilePath;
										},
										fail: (err) => {
											console.error('水印生成失败：', JSON.stringify(err)); // 输出完整错误信息
										}
									});
								}, 100)
							}
						});
					}
				});
		
			},
			submit() {
				uni.showToast({
					title: this.canvasImg
				});
			},
		}
	};

</script>
<style scoped lang="scss">
	.inspection {
		background-color: #f1f1f1;
	}

	.inspection_details {
		padding: 20rpx;
		box-sizing: border-box;
	}

	.textarea {
		border: 1rpx solid #dcdcdc;
		width: 710rpx;
		background-color: #fff;
	}

	.public {
		padding: 20rpx;
		box-sizing: border-box;
		font-size: 34rpx;
		background-color: #fff;
		margin-top: 30rpx;
	}

	.upload {
		display: flex;
		justify-content: space-between;
		align-items: center;
		flex-direction: row;
		height: 110rpx;
	}

	.upload_icon {
		font-size: 60rpx;
		color: #838383;
	}

	.content {
		display: flex;
		flex-direction: column;
	}

	.active {
		background-color: #009944;
		color: #fff;
	}

	.activeNo {
		background-color: #ff4244;
		color: #fff;
	}

	.submit {
		box-sizing: border-box;
		margin-top: 30rpx;
		padding: 20rpx;
		position: fixed;
		left: 0;
		bottom: 0rpx;
		background-color: #fff;
		width: 750rpx;
	}

	.submit_btn {
		height: 90rpx;
		background-color: #009944;
		color: #ffffff;
		font-size: 34rpx;
		border-radius: 20rpx;
		text-align: center;
		line-height: 90rpx;
		// margin-bottom: 30rpx;
		width: 100%;
		display: inline-block;
	}

	.margin {
		margin-top: 0;
		margin-bottom: 20rpx;
		display: flex;
		align-items: center;
		flex-direction: row;
	}

	.uni-input {
		flex: 1;
		height: 60rpx;
	}

	.garden_item {
		display: flex;
		align-items: center;
		flex-direction: row;
		padding: 20rpx 0;
	}

	.normal {
		border-bottom: 1rpx solid #b7b7b7;
	}

	.garden {
		width: 36rpx;
		height: 36rpx;
		border-width: 1rpx;
		border-color: #b7b7b7;
		border-style: solid;
		border-radius: 50%;
		display: flex;
		justify-content: center;
		align-items: center;
		margin-right: 20rpx;
	}

	.child_garden {
		width: 27rpx;
		height: 27rpx;
		border-radius: 50%;
	}

	.activeGarden {
		background-color: #009944;
	}

</style>

代码自己抽离 拿到最zhong的地址进行保存就成