WeChat applet wx.getImageInfo() to get image information

1. Knowledge points

2. Liezi

(1). When loading

<view class="zn-uploadimg">
	<image src="{{tempFilePaths}}" mode="aspecFill" style="width: 100%; height: 450rpx" />  
	<text>Image size: {{imgwidth}}px*{{imgheight}}px</text>
</view>

var app = getApp ()  
Page({
	data: {  
       tempFilePaths: '../uploads/foods.jpg',
       imgwidth:0,
       imgheight: 0,
	},
	onReady:function(){
	    // page rendering is complete  
		var _this = this;  
		wx.getImageInfo({
	      	src: _this.data.tempFilePaths,
	      	success: function (res) {
	      		_this.setData({
			      	imgwidth:res.width,
			      	imgheight:res.height,
			    })
	      	}
	    })
	}  
})

(2). When uploading pictures

<view  class="zn-uploadimg">
	<button type="primary"bindtap="chooseimage">获取图片</button>
	<image src="{{tempFilePaths}}" mode="aspecFill" style="width: 100%; height: 450rpx"/>  
	<text>图片的大小：{{imgwidth}}px*{{imgheight}}px</text>
</view>

.zn-uploadimg{
	padding:1rem;
}
.zn-uploadimg image{
	margin:1rem 0;
}

var app = getApp()  
Page({
	data: {  
       tempFilePaths: '', 
       imgwidth:0,
       imgheight:0,
	},
	/** 
	 * 上传图片
	 */
	chooseimage: function () {  
		var _this = this;  
		wx.chooseImage({  
			count: 1, // 默认9  
			sizeType: ['original', 'compressed'], // 可以指定是原图还是压缩图，默认二者都有  
			sourceType: ['album', 'camera'], // 可以指定来源是相册还是相机，默认二者都有  
			success: function (res) {  
				// 返回选定照片的本地文件路径列表，tempFilePath可以作为img标签的src属性显示图片  
				_this.setData({  
				    tempFilePaths:res.tempFilePaths  
				}) 
				wx.getImageInfo({
			      	src: res.tempFilePaths[0],
			      	success: function (res) {
			      		_this.setData({
					      	imgwidth:res.width,
					      	imgheight:res.height,
					    })
			      	}
			    }) 
			}  
		})  
	}  
})