• 解决ios横屏拍照图片自动旋转90度问题


    <!DOCTYPE html>  
    <html>  
    <head>  
        <meta charset="utf-8">  
        <meta name="viewport" content="initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />  
        <title>图片上传</title> 
        <script src="https://cdn.bootcss.com/exif-js/2.3.0/exif.min.js"></script>
        <style>
            * {
                margin: 0;
                padding: 0;
            }
            #app,body,html {
                height: 100%
            }
            body {
                font-size: 12px;
                -webkit-tap-highlight-color: transparent;
                font-family: Helvetica, Arial, sans-serif;
            }
        </style>
    </head>  
    <body>  
    
        <div style="height: 50px; line-height: 50px;text-align: center;border-bottom: 1px solid #171E28;">  
            上传图片:  
            <input type="file" accept="image/png, image/jpeg, image/jpg" id="uploadImage" onchange="selectFileImage(this);" />  
        </div>  
        <img style="100%;" id="myImage"/ alt="preview" src="">  
        
        <!-- 微信SDK -->
        <script src="https://res.wx.qq.com/open/js/jweixin-1.2.0.js"></script>
        <!-- 引入zepto -->
        <script src="https://cdn.bootcss.com/zepto/1.2.0/zepto.min.js"></script>
        <script>
                    
            function selectFileImage(fileObj) {  
                var file = fileObj.files['0'];  
                //图片方向角 added by lzk  
                var Orientation = null;  
                
                if (file) {  
                    console.log("正在上传,请稍后...");  
                    var rFilter = /^(image/jpeg|image/png)$/i; // 检查图片格式  
                    if (!rFilter.test(file.type)) {  
                        //showMyTips("请选择jpeg、png格式的图片", false);  
                        return;  
                    }  
                    // var URL = URL || webkitURL;  
                    //获取照片方向角属性,用户旋转控制  
                    EXIF.getData(file, function() {  
                    // alert(EXIF.pretty(this));  
                        EXIF.getAllTags(this);   
                        //alert(EXIF.getTag(this, 'Orientation'));   
                        Orientation = EXIF.getTag(this, 'Orientation');  
                        //return;  
                    });  
                    
                    var oReader = new FileReader();  
                    oReader.onload = function(e) {  
                        //var blob = URL.createObjectURL(file);  
                        //_compress(blob, file, basePath);  
                        var image = new Image();  
                        image.src = e.target.result;  
                        image.onload = function() {  
                            var expectWidth = this.naturalWidth;  
                            var expectHeight = this.naturalHeight;  
                            
                            if (this.naturalWidth > this.naturalHeight && this.naturalWidth > 800) {  
                                expectWidth = 800;  
                                expectHeight = expectWidth * this.naturalHeight / this.naturalWidth;  
                            } else if (this.naturalHeight > this.naturalWidth && this.naturalHeight > 1200) {  
                                expectHeight = 1200;  
                                expectWidth = expectHeight * this.naturalWidth / this.naturalHeight;  
                            }  
                            var canvas = document.createElement("canvas");  
                            var ctx = canvas.getContext("2d");  
                            canvas.width = expectWidth;  
                            canvas.height = expectHeight;  
                            ctx.drawImage(this, 0, 0, expectWidth, expectHeight);  
                            var base64 = null;  
                            //修复ios  
                            if (navigator.userAgent.match(/iphone/i)) {  
                                console.log('iphone');  
                                //alert(expectWidth + ',' + expectHeight);  
                                //如果方向角不为1,都需要进行旋转 added by lzk  
                                if(Orientation != "" && Orientation != 1){  
                                    alert('旋转处理');  
                                    switch(Orientation){  
                                        case 6://需要顺时针(向左)90度旋转  
                                            alert('需要顺时针(向左)90度旋转');  
                                            rotateImg(this,'left',canvas);  
                                            break;  
                                        case 8://需要逆时针(向右)90度旋转  
                                            alert('需要顺时针(向右)90度旋转');  
                                            rotateImg(this,'right',canvas);  
                                            break;  
                                        case 3://需要180度旋转  
                                            alert('需要180度旋转');  
                                            rotateImg(this,'right',canvas);//转两次  
                                            rotateImg(this,'right',canvas);  
                                            break;  
                                    }         
                                }  
                             
                            }base64 = canvas.toDataURL("image/jpeg",0.8)
                            document.getElementById('myImage').src = base64
                        };  
                    };  
                    oReader.readAsDataURL(file);  
                }  
            }  
            
            //对图片旋转处理 added by lzk  
            function rotateImg(img, direction,canvas) {    
                //alert(img);  
                //最小与最大旋转方向,图片旋转4次后回到原方向    
                var min_step = 0;    
                var max_step = 3;    
                //var img = document.getElementById(pid);    
                if (img == null)return;    
                //img的高度和宽度不能在img元素隐藏后获取,否则会出错    
                var height = img.height;    
                var width = img.width;    
                //var step = img.getAttribute('step');    
                var step = 2;    
                if (step == null) {    
                    step = min_step;    
                }    
                if (direction == 'right') {    
                    step++;    
                    //旋转到原位置,即超过最大值    
                    step > max_step && (step = min_step);    
                } else {    
                    step--;    
                    step < min_step && (step = max_step);    
                }    
                
                //旋转角度以弧度值为参数    
                var degree = step * 90 * Math.PI / 180;    
                var ctx = canvas.getContext('2d');    
                switch (step) {    
                    case 0:    
                        canvas.width = width;    
                        canvas.height = height;    
                        ctx.drawImage(img, 0, 0);    
                        break;    
                    case 1:    
                        canvas.width = height;    
                        canvas.height = width;    
                        ctx.rotate(degree);    
                        ctx.drawImage(img, 0, -height);    
                        break;    
                    case 2:    
                        canvas.width = width;    
                        canvas.height = height;    
                        ctx.rotate(degree);    
                        ctx.drawImage(img, -width, -height);    
                        break;    
                    case 3:    
                        canvas.width = height;    
                        canvas.height = width;    
                        ctx.rotate(degree);    
                        ctx.drawImage(img, -width, 0);    
                        break;    
                }    
            } 
        </script>
    </body>  
    
    </html>  
  • 相关阅读:
    面试题58:翻转字符串
    面试题57_2:和为S的连续正数序列
    面试题57:和为S的数字
    面试题56:数组中数字出现的次数
    面试题55_2:平衡二叉树
    面试题54:二叉搜索树的第k大节点
    面试题55_1:二叉树的深度
    tortoisegit 本地创建的分支 push github
    TortoiseGit 拉取分支
    tortoiseGIT 本地分支创建合并
  • 原文地址:https://www.cnblogs.com/lanshengzhong/p/9008562.html
Copyright © 2020-2023  润新知