![[H5-Compress-Image]利用canvas实现 javascript 图片压缩处理_基于requirejs模块化的代码实现](https://image.shishitao.com:8440/aHR0cHM6Ly9ia3FzaW1nLmlrYWZhbi5jb20vdXBsb2FkL2NoYXRncHQtcy5wbmc%2FIQ%3D%3D.png?!?w=700&webp=1 "[H5-Compress-Image]利用canvas实现 javascript 图片压缩处理_基于requirejs模块化的代码实现")
// 还存在有问题的代码，问题在于processFile()中
// 问题：在ipone 5c 下，某些图片压缩处理后，上传到服务器生成的文件size为0，即是空白
;define(['mod/tool/formSubmit'] ,function(o_formSubmit) {
return {
init: function(id) {
var self = this;
self.sniff(id);
var $img = '';
var $inputField = '';
},
sniff: function(id) {
var self = this;
if (window.File && window.FileReader && window.FormData) {
$inputField = $('#' + id);
$inputField.on('change', function (e) {
var file = e.target.files[0];
if($('.c-img-wrap').length >= 9)
{
Hnb.ui.showError('不能上传超过9张图片' , 3000);
return ;
}
if (file) {
//alert(file.type);
//if(!file.type) file.type='image/jpeg';
//if (/^image\//i.test(file.type)) {
if($("#id_img_list").parent().attr("scrollWidth") > $(window).width())
{
$("#id_img_list").parent().scrollLeft($("#id_img_list").parent().attr("scrollWidth") - $(window).width());
}
$img = $('<a class="bg c-img-wrap" href="javascript:void(null);"><i class="pa c-img-close"></i></a>').insertBefore($("#id_last_img_wrap"));
self.readFile(file);
//} else {
// Hnb.ui.showError('请在浏览器中打开该页面上传图片' , 3000);
// $inputField.val('');
//}
}
});
$inputField.val('');
} else {
Hnb.ui.showError("当前您的浏览器不支持图片上传，请选择其他的浏览器进行上传。" , 3000);
$inputField.val('');
}
},
readFile: function (file) {
var self = this;
var reader = new FileReader();
var head = '';
reader.onloadend = function () {
//reader.onload = function () {
head = reader.result.substr(0, 20);
alert('head:' + head);
alert('file_type:' + file.type);
self.processFile(reader.result, file.type);
}
reader.onerror = function () {
Hnb.ui.showError('上传图片过程中发生了网络异常，请稍后重试。' , 3000);
}
reader.readAsDataURL(file);
},
processFile: function (dataURL, fileType) {
var self = this;
var maxWidth = 3120;
var maxHeight = 4208;
var image = new Image();
image.src = dataURL;
image.onload = function () {
var width = image.width;
var height = image.height;
var shouldResize = (width > maxWidth) || (height > maxHeight);
if (!shouldResize) {
//self.submitFile(dataURL);
self.sendFile(dataURL , fileType);
return;
}
var newWidth;
var newHeight;
if (width > height) {
newHeight = height * (maxWidth / width);
newWidth = maxWidth;
} else {
newWidth = width * (maxHeight / height);
newHeight = maxHeight;
}
var canvas = document.createElement('canvas');
canvas.width = newWidth;
canvas.height = newHeight;
var context = canvas.getContext('2d');
context.drawImage(this, 0, 0, newWidth, newHeight);
dataURL = canvas.toDataURL(fileType);
alert(dataURL.length);
//window.location = dataURL;
//self.sendFile(dataURL , fileType);
/*
var file = canvas.mozGetAsFile("foo.png");
var f = document.createElement("form");
var i = document.createElement("input"); //input element, text
i.setAttribute('type',"file");
i.setAttribute('name',"upfile");
i.setAttribute('value' , dataURL);
f.appendChild(i);
*/
//$("#id_upfile").val(dataURL);
//document.forms[0].upfile.val = dataURL;
//window.location = dataURL;
//var formData = new FormData(document.forms[0]);
//console.log(document.forms[0]);
//console.log(formData.get('upfile'));
//console.log(formData);
//return;
//formData.append('imageData', dataURL);
//formData.delete('upfile');
//console.log($inputField.files);
//formData.set('upfile', $inputField.files[0] , dataURL);
//self.submitFile($(f));
};
image.onerror = function () {
//alert('There was an error processing your file!');
Hnb.ui.showError('上传图片处理过程中发生了网络异常，请稍后重试。' , 3000);
};
},
submitFile: function(f) {
var self = this;
//console.log(f);
o_formSubmit.create(f , Hnb.WWW_CGI_URL + "/image/saveInCrossDomain").start().done(function(json_msg){
if(json_msg.state || !json_msg.data.real_url) {
Hnb.ui.showError("上传图片失败！" , 3000);
$img.remove();
} else {
console.log(json_msg.data);
$img.removeClass("bg").addClass("comBg").css("background-image" , "url(" + json_msg.data.real_url + ")").attr("hnb-src" , json_msg.data.real_url);
//$img.html('<img src="' + json_msg.data.real_url + '" alt="帖子图片">');
$("#id_top_wrap").addClass("active");
//$img.html("");
}
}).fail(function(json_error){
$img.remove();
Hnb.ui.showError("您的网络有点慢，请稍后重试" , 3000);
}).always(function(){
$img.removeClass("bg");
self.isSubmitingImgNum--;
});
},
sendFile: function (fileData , fileType) {
var formData = new FormData();
formData.append('imageData', fileData);
formData.append('imageType' , fileType);
$.ajax({
type: 'POST',
timeout: 300000,
url: Hnb.WWW_CGI_URL + '/image/saveCndCompressImage',
data: formData,
contentType: false,
processData: false,
success: function (json_msg) {
//console.log('返回json数据' + json_msg);
var json_msg = $.parseJSON(json_msg);
if(!json_msg.state)
{
// 跨域请求处理
document.domain = 'hin*.com';
// 可以将上传到线上的图片，追加到预览图位置
// ...
} else {
Hnb.ui.showError('您的网络有点慢，请稍后再上传。' , 3000);
}
},
error: function (json_msg) {
Hnb.ui.showError('上传图片发生了网络异常，请稍后重试。' , 3000);;
}
}).always(
function() {
$inputField.val("");
$img.removeClass("bg");
}
);
}
}
});
// 修改后，可以正常使用的代码
;define(['mod/tool/formSubmit'] ,function(o_formSubmit) {
return {
init: function(id) {
var self = this;
self.sniff(id);
var $img = '';
var $inputField = '';
},
sniff: function(id) {
var self = this;
if (window.File && window.FileReader && window.FormData) {
$inputField = $('#' + id);
$inputField.on('change', function (e) {
var file = e.target.files[0];
if($('.c-img-wrap').length >= 9)
{
Hnb.ui.showError('不能上传超过9张图片' , 3000);
return ;
}
if (file) {
//if(!file.type) file.type='image/jpeg';
//if (/^image\//i.test(file.type)) {
if($("#id_img_list").parent().attr("scrollWidth") > $(window).width())
{
$("#id_img_list").parent().scrollLeft($("#id_img_list").parent().attr("scrollWidth") - $(window).width());
}
$img = $('<a class="bg c-img-wrap" href="javascript:void(null);"><i class="pa c-img-close"></i></a>').insertBefore($("#id_last_img_wrap"));
self.readFile(file);
}
});
} else {
Hnb.ui.showError("当前您的浏览器不支持图片上传，请选择其他的浏览器进行上传。", 3000);
//$inputField.val('');
}
$inputField.val('');
},
readFile: function (file) {
var self = this;
var reader = new FileReader();
var head = '';
reader.onloadend = function () {
//reader.onload = function () {
//head = reader.result.substr(0, 20);
self.processFile(reader.result, file.type);
}
reader.onerror = function () {
Hnb.ui.showError('上传图片过程中发生了网络异常，请稍后重试。', 3000);
return;
}
reader.readAsDataURL(file);
$inputField.val('');
},
processFile: function (dataURL, fileType) {
var self = this;
var unitSize = 480;
var image = new Image();
image.src = dataURL;
image.onload = function () {
var wFactor = image.width / unitSize;
var hFactor = image.height / unitSize;
var minFactor = Math.round(Math.min(wFactor, hFactor));
if (minFactor < 2) {
//self.submitFile(dataURL);
self.sendFile(dataURL, fileType);
return;
}
var newWidth = image.width / minFactor;
var newHeight = image.height / minFactor;
var canvas = document.createElement('canvas');
canvas.width = newWidth;
canvas.height = newHeight;
var context = canvas.getContext('2d');
context.drawImage(this, 0, 0, newWidth, newHeight);
dataURL = canvas.toDataURL(fileType);
//window.location = dataURL;
self.sendFile(dataURL, fileType);
};
image.onerror = function () {
Hnb.ui.showError('上传图片处理过程中发生了网络异常，请稍后重试。' , 3000);
$inputField.val('');
};
},
submitFile: function(f) {
var self = this;
o_formSubmit.create(f , Hnb.WWW_CGI_URL + "/image/saveInCrossDomain").start().done(function(json_msg){
if(json_msg.state || !json_msg.data.real_url) {
Hnb.ui.showError("上传图片失败！" , 3000);
$img.remove();
} else {
$img.removeClass("bg").addClass("comBg").css("background-image" , "url(" + json_msg.data.real_url + ")").attr("hnb-src" , json_msg.data.real_url);
//$img.html('<img src="' + json_msg.data.real_url + '" alt="帖子图片">');
$("#id_top_wrap").addClass("active");
//$img.html("");
}
}).fail(function(json_error){
$img.remove();
Hnb.ui.showError("您的网络有点慢，请稍后重试" , 3000);
}).always(function(){
$img.removeClass("bg");
self.isSubmitingImgNum--;
});
},
sendFile: function (fileData , fileType) {
var formData = new FormData();
formData.append('imageData', fileData);
formData.append('imageType' , fileType);
$.ajax({
type: 'POST',
timeout: 300000,
url: Hnb.WWW_CGI_URL + '/image/saveCndCompressImage',
data: formData,
contentType: false,
processData: false,
success: function (json_msg) {
var json_msg = $.parseJSON(json_msg);
if(!json_msg.state)
{
document.domain = 'hin*.com';
$img.removeClass("bg").addClass("comBg").css("background-image" , "url(" + json_msg.data.real_url + ")").attr("hnb-src" , json_msg.data.real_url);
//$img.html('<img src="' + json_msg.data.real_url + '" alt="帖子图片">');
$("#id_top_wrap").addClass("active");
} else {
Hnb.ui.showError('您的网络有点慢，请稍后再上传。' , 3000);
}
},
error: function (json_msg) {
Hnb.ui.showError('上传图片发生了网络异常，请稍后重试。' , 3000);;
}
}).always(
function() {
$inputField.val("");
$img.removeClass("bg");
}
);
}
}
});
