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html5 canvas 的涂鸦画板,可以加载图片进行涂鸦,也可以下载
服务器使用的php
上传的图片不能超过1M,只能是jpg或者png 格式的
演示地址的服务器网速不怎么样,读取文件可能很慢,到达100%的时候点击读取文件,如果没显示就多点几次
​1. [代码]主页面     

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>涂鸦画板</title>
<script type="text/javascript" src="jquery-1.8.3.js"></script>
<script type="text/javascript" src="jquery.form.js"></script>
<link href="index.css" rel="stylesheet" type="text/css">
 
</head>
<body>
    <div id="chooseColor"></div>
    <div id="chooseSize"></div>
    <div id="paint">
        <canvas id="pad" width="800" height="600" />
    </div>
    <input type="button" id="download" value="下载" />
    <!-- 上传图片  -->
    <input type="file" name="mypic" id="chooseFile" />
    <input type="button" value="读取文件" id="load" />
    <!-- 进度条 -->
    <div class="progress">
        <span class="bar"></span><span class="percent">0%</span >
    </div>
    <!-- 隐藏区域 -->
    <img id="tulip" src="" alt="加载显示区" />
</body>
<script type="text/javascript" src="index.js"></script>
</html>
2. [代码]页面的简单排版     
body,input {
    font-size: 9pt;
}
 
#paint,#chooseSize {
    clear: both;
}
 
.option {
    float: left;
    width: 20px;
    height: 20px;
    border: 2px solid #cccccc;
    margin-right: 4px;
    margin-bottom: 4px;
}
 
.active {
    border: 2px solid black;
}
 
.lw {
    text-align: center;
    vertical-align: middle;
}
 
img.output {
    border: 1px solid green;
}
 
#pad {
    border: 2px solid gray;
    cursor: arrow;
}
 
#chooseFile {
    float: left;
    width: 140px;
}
 
#tulip {
    display: none;
}
 
#download {
    margin-left: 550px;
}
 
#load {
    float: left;
    width: 80px;
}
3. [代码]画图,上传,下载处理     

$(document).ready(function() {
    paint();
    downloadPic();
    loadImg();
    uploadImg();
});
 
/**
 * 绘画
 */
function paint() {
    chooseColor();
    chooseSize();
    canvas();
}
 
/**
 * 颜色选择器
 */
function chooseColor() {
    var colors = "red;orange;yellow;green;blue;indigo;purple;black;white".split(\';\');
    var sb = [];
    $.each(colors,function(i,v){
        sb.push("<div class=\'option\' style=\'background-color:" + v + "\'></div>");
    });
    $("#chooseColor").html(sb.join("\n"));
}
 
/**
 * 大小选择器
 */
function chooseSize(){
    sb = [];
    for (var i = 1; i <= 9; i++) sb.push("<div class=\'option lw\'>" + "<div style=\'margin-top:#px;margin-left:#px;width:%px;height:%px\'></div></div>".replace(/%/g, i).replace(/#/g, 10 - i / 2));
    $("#chooseSize").html(sb.join(\'\n\'));
}
 
/**
 * 画图
 */
function canvas(){
    var $clrs = $("#chooseColor .option");
    var $lws = $("#chooseSize .option");
    $clrs.click(function(){
        $clrs.removeClass("active");
        $(this).addClass("active");
        p_color = this.style.backgroundColor;
        $lws.children("div").css("background-color",p_color);
    }).first().click();
     
    //点选线条粗细选项时切换焦点并取得宽度存入p_width
    $lws.click(function(){
        $lws.removeClass("active");
        $(this).addClass("active");
        p_width = $(this).children("div").css("width").replace("px","");
         
    }).eq(3).click();
     
    // 取得canvas context
    var $canvas = $("#pad");
    var ctx = $canvas[0].getContext("2d");
    ctx.lineCap = "round";
    ctx.fillStyle = "white"; //整个canvas涂上白色的背景,避免PNG的透明底色效果
    ctx.fillRect(0,0,$canvas.width(),$canvas.height());
    var drawMode = false;
     
    // canvas点选,移动,放开按键时进行绘图动作
    $canvas.mousedown(function(e){
        ctx.beginPath();
        ctx.strokeStyle = p_color;
        ctx.lineWidth = p_width;
        ctx.moveTo(e.pageX - $canvas.position().left, e.pageY - $canvas.position().top);
        drawMode = true;
    }).mousemove(function(e){
        if(drawMode){
            ctx.lineTo(e.pageX - $canvas.position().left, e.pageY - $canvas.position().top);
            ctx.stroke();
        }
    }).mouseup(function(e){
        drawMode = false;
    });
}
 
/**
 * 下载当前所绘制的图像
 */
function downloadPic(){
    // 使用toDataURL()将图转换成png文件
    var saveFile = function(data, filename) {
        var save_link = document.createElementNS(\'http://www.w3.org/1999/xhtml\', \'a\');
        save_link.href = data;
        save_link.download = filename;
        var event = document.createEvent(\'MouseEvents\');
        event.initMouseEvent(\'click\', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
        save_link.dispatchEvent(event);婚纱摄影
    };http://www.huiyi8.com/hunsha/​
    $("#download").click(function() {
        var myCanvas = document.getElementById("pad");
        var image = myCanvas.toDataURL("image/png").replace("image/png", "image/octet-stream");
        // window.location.href=image;
        var filename = \'paint_\' + (new Date()).getTime() + \'.png\';
        saveFile(image, filename);
    });
}
 
 
//获取当前文件名
function ch_(url){  
    url=url.split("\\");//这里要将 \ 转义一下
    var filename = url[url.length-1];
    return filename;
}
 
 
//加载隐藏模块中的图片
function loadImg(){
    $(\'#load\').click(function(){
        // 加载到canvas
        var c= document.getElementById("pad");
        var ctx = c.getContext("2d");
        var img=document.getElementById("tulip");
        ctx.drawImage(img,0,0);
    });
}
 
/**
 * 上传图片
 */
function uploadImg(){
    var bar = $(\'.bar\');
    var percent = $(\'.percent\');
    var showimg = $(\'#showimg\');
    var progress = $(".progress");
    $("#chooseFile").wrap("<form id=\'myupload\' action=\'upload.php\' method=\'post\' enctype=\'multipart/form-data\'></form>");
    $("#chooseFile").change(function(){
        $("#myupload").ajaxSubmit({
            dataType: \'json\',
            uploadProgress: function(event, position, total, percentComplete) {
                var percentVal = percentComplete + \'%\';
                bar.width(percentVal);
                percent.html(percentVal);
            },
            success: function(data){
                // alert(\'上传成功\');
                var file = $(\'#chooseFile\').val();
                var filename = ch_(file);
                var src = \'paint/\' + filename;
                $(\'#tulip\').attr(\'src\',src);
            },
            error: function(xhr){
                alert(\'上传失败\');
            }
        });
    });
}
4. [代码]服务器上传处理   
<?php
$picname = $_FILES [\'mypic\'] [\'name\'];
$picsize = $_FILES [\'mypic\'] [\'size\'];
if ($picname != \'\') {
    if ($picsize > 1024000) {
        echo \'图片的大小不能超过1M\';
        exit ();
    }
    $type = strstr ( $picname, \'.\' );
    if ($type != \'.jpg\' && $type != \'.png\') {
        echo \'图片格式不对\';
        exit ();
    }
    $pics = $picname;
    // 上传路径
    $pic_path = \'paint/\' . $pics;
    move_uploaded_file ( $_FILES [\'mypic\'] [\'tmp_name\'], $pic_path );
}
$size = round ( $picsize / 1024, 2 );
$arr = array (
        \'name\' => $picname,
        \'pic\' => $pics,
        \'size\' => $size
);
echo json_encode ( $arr );
?>

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