Question

我创建了一个可以上传图片的网站，然后在点击图片点后，该网站将返回您点击的点的十六进制代码。

您可以单击输入框（按钮）以上传图像，但我也希望在拖放图像后使其正常工作。

我使用标签让按钮看起来很漂亮。所以，我有一个隐藏输入框的脚本：

<script>
    (function(e,t,n){
        var r=e.querySelectorAll("html")[0];
        r.className=r.className.replace(/(^|\s)no-js(\s|$)/,"$1js$2")
    })
    (document,window,0);
</script>

等效的HTML行是：

<html lang="en" class="no-js">

这是输入框的HTML脚本和标签：

<input type="file" name="file_upload[]" id="file_upload" class="inputfile inputfile-2" data-multiple-caption="{count} files selected" multiple />
<label for="file_upload">
    <svg xmlns="http://www.w3.org/2000/svg" width="20" height="17" viewBox="0 0 20 17"><path d="M10 0l-5.2 4.9h3.3v5.1h3.8v-5.1h3.3l-5.2-4.9zm9.3 11.5l-3.2-2.1h-2l3.4 2.6h-3.5c-.1 0-.2.1-.2.1l-.8 2.3h-6l-.8-2.2c-.1-.1-.1-.2-.2-.2h-3.6l3.4-2.6h-2l-3.2 2.1c-.4.3-.7 1-.6 1.5l.6 3.1c.1.5.7.9 1.2.9h16.3c.6 0 1.1-.4 1.3-.9l.6-3.1c.1-.5-.2-1.2-.7-1.5z"/></svg> 
    <span>CHOOSE A FILE</span>
</label>

如果我删除标签并取消隐藏输入框，则拖放工作正常。

现在，我试图在此框中拖放文件后使其工作：

该片段如下：

//Script that hides the input box (label is a substitute)
(function(e,t,n){var r=e.querySelectorAll("html")[0];r.className=r.className.replace(/(^|\s)no-js(\s|$)/,"$1js$2")})(document,window,0);

//Hex picker function
var $picked = $("#picked"); // Just to preview picked colors
	var canvas = $('#canvas_picker')[0];
	var context = canvas.getContext('2d');


	$("#file_upload").change(function (e) {
	  var F = this.files[0];
	  var reader = new FileReader();
	  reader.onload = imageIsLoaded;
	  reader.readAsDataURL(F);  
	});

	function imageIsLoaded(e) {
	  var img = new Image();
	  img.onload = function(){
		canvas.width  = this.width;
		canvas.height = this.height;
		context.drawImage(this, 0, 0);
	  };
	  img.src = e.target.result;
	}

	$('#canvas_picker').click(function(event){
	  var x = event.pageX - $(this).offset().left;
	  var y = event.pageY - $(this).offset().top;
	  var img_data = context.getImageData(x,y , 1, 1).data;
	  var R = img_data[0];
	  var G = img_data[1];
	  var B = img_data[2]; 
	  var rgb = R + ',' + G + ',' + B ;
	  var hex = rgbToHex(R,G,B);
	  $('#rgb input').val( rgb );
	  $('#hex input').val('#' + hex);
	  $picked.append("<span style='background:#"+hex+"'>#"+hex+"</span>");
	});

	function rgbToHex(R, G, B) {
	  return toHex(R) + toHex(G) + toHex(B);
	}

	function toHex(n) {
	  n = parseInt(n, 10);
	  if (isNaN(n))  return "00";
	  n = Math.max(0, Math.min(n, 255));
	  return "0123456789ABCDEF".charAt((n - n % 16) / 16)  + "0123456789ABCDEF".charAt(n % 16);
	}

/* latin-ext */
@font-face {
  font-family: 'Lato';
  font-style: normal;
  font-weight: 300;
  src: local('Lato Light'), local('Lato-Light'), url(http://fonts.gstatic.com/s/lato/v11/dPJ5r9gl3kK6ijoeP1IRsvY6323mHUZFJMgTvxaG2iE.woff2) format('woff2');
  unicode-range: U+0100-024F, U+1E00-1EFF, U+20A0-20AB, U+20AD-20CF, U+2C60-2C7F, U+A720-A7FF;
}
/* latin */
@font-face {
  font-family: 'Lato';
  font-style: normal;
  font-weight: 300;
  src: local('Lato Light'), local('Lato-Light'), url(http://fonts.gstatic.com/s/lato/v11/EsvMC5un3kjyUhB9ZEPPwg.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2212, U+2215, U+E0FF, U+EFFD, U+F000;
}

body {
    background: hsl(184,65%,49%);
    font-family: 'Lato';
    color: #000;
    font: 15px/1.4em;
}

canvas{
  background: hsl(184,65%,49%);
 
}

#picked span{
  display:inline-block;
  width:50px;
  height:50px;
  margin:3px;
  text-align:center;
  text-shadow:1px 1px 1px #000;
  font:8px/50px Arial;
  color:#fff;
}

.js .inputfile {
    width: 0.1px;
    height: 0.1px;
    opacity: 0;
    overflow: hidden;
    position: absolute;
    z-index: -1;
}

.inputfile + label {
    max-width: 80%;
    font-weight: 700;
    text-overflow: ellipsis;
    white-space: nowrap;
    cursor: pointer;
    display: inline-block;
    overflow: hidden;
    padding: 0.625rem 1.25rem;
}

.no-js .inputfile + label {
    display: none;
}

.inputfile:focus + label,
.inputfile.has-focus + label {
    outline: 1px dotted #000;
    outline: -webkit-focus-ring-color auto 5px;
}


.inputfile + label svg {
    width: 1em;
    height: 1em;
    vertical-align: middle;
    fill: currentColor;
    margin-top: -0.25em;
    margin-right: 0.25em;
}


.inputfile-2 + label {
    width: 90%;
    max-width: 220px;
    background: #fff;
    color: #333;
    border: none;
    font-family: Lato;
	text-align: center;
    font-size: 1vw;
    padding: 25px 0 25px 0;
    display: inline-block;
    letter-spacing: 1px;
    font-weight: 700;
    outline: none;
    position: relative;
    -webkit-transition: all 0.3s;
    -moz-transition: all 0.3s;
    transition: all 0.3s;
    border: 3px solid #333;
}



/*  COLUMN SETUP  */
.col2 {
	display: block;
	float:left;
	margin: 0;
}
.col2:first-child { margin-left: 0; }

/*  GROUPING  */
.group2:before,
.group2:after { content:""; display:table; }
.group2:after { clear:both;}
.group2 { zoom:1; /* For IE 6/7 */ }

/*  GRID OF THREE  */
.span_3_of_3 { width: 100%; }
.span_2_of_3 { width: 66.66%; }
.span_1_of_3 { width: 33.33%; }

/*  GO FULL WIDTH BELOW 480 PIXELS */
@media only screen and (max-width: 480px) {
	.col2 {  margin: 0 }
	.span_3_of_3, .span_2_of_3, .span_1_of_3 { width: 100%; }
}


/*  COLUMN SETUP  */
.col {
	display: block;
	float:left;
	margin: 1% 0 1% 2%;
}
.col:first-child { margin-left: 0; }

/*  GROUPING  */
.group:before,
.group:after { content:""; display:table; }
.group:after { clear:both;}
.group { zoom:1; /* For IE 6/7 */ }
/*  GRID OF FOUR  */
.span_4_of_4 {
	width: 100%;
}
.span_3_of_4 {
	width: 74.5%;
}
.span_2_of_4 {
	width: 49%;
}
.span_1_of_4 {
	width: 23.5%;
}

/*  GO FULL WIDTH BELOW 480 PIXELS */
@media only screen and (max-width: 480px) {
	.col {  margin: 1% 0 1% 0%; }
	.span_1_of_4, .span_2_of_4, .span_3_of_4, .span_4_of_4 { width: 100%; }
}


/*  SECTIONS  */
.section {
	margin-left:5%;
	margin-right:5%;
	clear: both;
}

/*  COLUMN SETUP  */
.col {
	display: block;
	float:left;
	margin: 1% 0 1% 2%;
}
.col:first-child { margin-left: 0; }

/*  GROUPING  */
.group:before,
.group:after { content:""; display:table; }
.group:after { clear:both;}
.group { zoom:1; /* For IE 6/7 */ }
/*  GRID OF FOUR  */
.span_4_of_4 {
	width: 100%;
}
.span_3_of_4 {
	width: 74.5%;
}
.span_2_of_4 {
	width: 49%;
}
.span_1_of_4 {
	width: 23.5%;
}

/*  GO FULL WIDTH BELOW 480 PIXELS */
@media only screen and (max-width: 480px) {
	.col {  margin: 1% 0 1% 0%; }
	.span_1_of_4, .span_2_of_4, .span_3_of_4, .span_4_of_4 { width: 100%; }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<html lang="en" class="no-js">

<div id="picked"></div>
	<div class="section group">
		<div class="col span_1_of_4">
			<input type="file" name="file_upload[]" id="file_upload" class="inputfile inputfile-2" data-multiple-caption="{count} files selected" multiple /><label for="file_upload"><svg xmlns="http://www.w3.org/2000/svg" width="20" height="17" viewBox="0 0 20 17"><path d="M10 0l-5.2 4.9h3.3v5.1h3.8v-5.1h3.3l-5.2-4.9zm9.3 11.5l-3.2-2.1h-2l3.4 2.6h-3.5c-.1 0-.2.1-.2.1l-.8 2.3h-6l-.8-2.2c-.1-.1-.1-.2-.2-.2h-3.6l3.4-2.6h-2l-3.2 2.1c-.4.3-.7 1-.6 1.5l.6 3.1c.1.5.7.9 1.2.9h16.3c.6 0 1.1-.4 1.3-.9l.6-3.1c.1-.5-.2-1.2-.7-1.5z"/></svg><span>CHOOSE A FILE</span></label>
		</div>
		<div class="col span_3_of_4">
		    <canvas width="600" height="300" id="canvas_picker"></canvas>
		</div>
	</div>
  
  <html/>

Answer 1

对不起代码格式化，我没有太多时间，它花了我一点点找到，但你的解决方案是优雅所以我认为这是值得的。这是我从上一次拖拽实验中收集的内容：

您似乎需要取消这两个其他拖动事件才能正确捕获放置事件
您需要抓住originalEvent才能获取文件
还发现，出于安全原因，文件输入值不可编辑，但您可以直接从您拥有的内容重绘。也许有一个委托该事件的解决方案，但我现在不会检查这个。

注意：在本地页面上，标题中包含jQuery和样式，以及`$（document）.ready中的脚本，在html之后，输入没有消失（相同，我没时间检查原因）

//Script that hides the input box (label is a substitute)
(function(e,t,n){var r=e.querySelectorAll("html")[0];r.className=r.className.replace(/(^|\s)no-js(\s|$)/,"$1js$2")})(document,window,0);

//Hex picker function
var $picked = $("#picked"); // Just to preview picked colors
	var canvas = $('#canvas_picker')[0];
	var context = canvas.getContext('2d');


	$("#file_upload").change(function (e) {
	  var F = this.files[0];
	  var reader = new FileReader();
	  reader.onload = imageIsLoaded;
	  reader.readAsDataURL(F);  
	});

$('#fileLabel').bind({
	dragover: function(e){
		e.preventDefault();
		e.stopPropagation();
	},
	dragleave: function(e){
		e.preventDefault();
		e.stopPropagation();
	},
	drop: function(e){
		e.preventDefault();
		e.stopPropagation();
		var F = e.originalEvent.dataTransfer.files[0];
		var reader = new FileReader();
		reader.onload = imageIsLoaded;
		reader.readAsDataURL(F);
	}
});

	function imageIsLoaded(e) {
	  var img = new Image();
	  img.onload = function(){
		canvas.width  = this.width;
		canvas.height = this.height;
		context.drawImage(this, 0, 0);
	  };
	  img.src = e.target.result;
	}

	$('#canvas_picker').click(function(event){
	  var x = event.pageX - $(this).offset().left;
	  var y = event.pageY - $(this).offset().top;
	  var img_data = context.getImageData(x,y , 1, 1).data;
	  var R = img_data[0];
	  var G = img_data[1];
	  var B = img_data[2]; 
	  var rgb = R + ',' + G + ',' + B ;
	  var hex = rgbToHex(R,G,B);
	  $('#rgb input').val( rgb );
	  $('#hex input').val('#' + hex);
	  $picked.append("<span style='background:#"+hex+"'>#"+hex+"</span>");
	});

	function rgbToHex(R, G, B) {
	  return toHex(R) + toHex(G) + toHex(B);
	}

	function toHex(n) {
	  n = parseInt(n, 10);
	  if (isNaN(n))  return "00";
	  n = Math.max(0, Math.min(n, 255));
	  return "0123456789ABCDEF".charAt((n - n % 16) / 16)  + "0123456789ABCDEF".charAt(n % 16);
	}

/* latin-ext */
@font-face {
  font-family: 'Lato';
  font-style: normal;
  font-weight: 300;
  src: local('Lato Light'), local('Lato-Light'), url(http://fonts.gstatic.com/s/lato/v11/dPJ5r9gl3kK6ijoeP1IRsvY6323mHUZFJMgTvxaG2iE.woff2) format('woff2');
  unicode-range: U+0100-024F, U+1E00-1EFF, U+20A0-20AB, U+20AD-20CF, U+2C60-2C7F, U+A720-A7FF;
}
/* latin */
@font-face {
  font-family: 'Lato';
  font-style: normal;
  font-weight: 300;
  src: local('Lato Light'), local('Lato-Light'), url(http://fonts.gstatic.com/s/lato/v11/EsvMC5un3kjyUhB9ZEPPwg.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2212, U+2215, U+E0FF, U+EFFD, U+F000;
}

body {
    background: hsl(184,65%,49%);
    font-family: 'Lato';
    color: #000;
    font: 15px/1.4em;
}

canvas{
  background: hsl(184,65%,49%);
 
}

#picked span{
  display:inline-block;
  width:50px;
  height:50px;
  margin:3px;
  text-align:center;
  text-shadow:1px 1px 1px #000;
  font:8px/50px Arial;
  color:#fff;
}

.js .inputfile {
    width: 0.1px;
    height: 0.1px;
    opacity: 0;
    overflow: hidden;
    position: absolute;
    z-index: -1;
}

.inputfile + label {
    max-width: 80%;
    font-weight: 700;
    text-overflow: ellipsis;
    white-space: nowrap;
    cursor: pointer;
    display: inline-block;
    overflow: hidden;
    padding: 0.625rem 1.25rem;
}

.no-js .inputfile + label {
    display: none;
}

.inputfile:focus + label,
.inputfile.has-focus + label {
    outline: 1px dotted #000;
    outline: -webkit-focus-ring-color auto 5px;
}


.inputfile + label svg {
    width: 1em;
    height: 1em;
    vertical-align: middle;
    fill: currentColor;
    margin-top: -0.25em;
    margin-right: 0.25em;
}


.inputfile-2 + label {
    width: 90%;
    max-width: 220px;
    background: #fff;
    color: #333;
    border: none;
    font-family: Lato;
	text-align: center;
    font-size: 1vw;
    padding: 25px 0 25px 0;
    display: inline-block;
    letter-spacing: 1px;
    font-weight: 700;
    outline: none;
    position: relative;
    -webkit-transition: all 0.3s;
    -moz-transition: all 0.3s;
    transition: all 0.3s;
    border: 3px solid #333;
}



/*  COLUMN SETUP  */
.col2 {
	display: block;
	float:left;
	margin: 0;
}
.col2:first-child { margin-left: 0; }

/*  GROUPING  */
.group2:before,
.group2:after { content:""; display:table; }
.group2:after { clear:both;}
.group2 { zoom:1; /* For IE 6/7 */ }

/*  GRID OF THREE  */
.span_3_of_3 { width: 100%; }
.span_2_of_3 { width: 66.66%; }
.span_1_of_3 { width: 33.33%; }

/*  GO FULL WIDTH BELOW 480 PIXELS */
@media only screen and (max-width: 480px) {
	.col2 {  margin: 0 }
	.span_3_of_3, .span_2_of_3, .span_1_of_3 { width: 100%; }
}


/*  COLUMN SETUP  */
.col {
	display: block;
	float:left;
	margin: 1% 0 1% 2%;
}
.col:first-child { margin-left: 0; }

/*  GROUPING  */
.group:before,
.group:after { content:""; display:table; }
.group:after { clear:both;}
.group { zoom:1; /* For IE 6/7 */ }
/*  GRID OF FOUR  */
.span_4_of_4 {
	width: 100%;
}
.span_3_of_4 {
	width: 74.5%;
}
.span_2_of_4 {
	width: 49%;
}
.span_1_of_4 {
	width: 23.5%;
}

/*  GO FULL WIDTH BELOW 480 PIXELS */
@media only screen and (max-width: 480px) {
	.col {  margin: 1% 0 1% 0%; }
	.span_1_of_4, .span_2_of_4, .span_3_of_4, .span_4_of_4 { width: 100%; }
}


/*  SECTIONS  */
.section {
	margin-left:5%;
	margin-right:5%;
	clear: both;
}

/*  COLUMN SETUP  */
.col {
	display: block;
	float:left;
	margin: 1% 0 1% 2%;
}
.col:first-child { margin-left: 0; }

/*  GROUPING  */
.group:before,
.group:after { content:""; display:table; }
.group:after { clear:both;}
.group { zoom:1; /* For IE 6/7 */ }
/*  GRID OF FOUR  */
.span_4_of_4 {
	width: 100%;
}
.span_3_of_4 {
	width: 74.5%;
}
.span_2_of_4 {
	width: 49%;
}
.span_1_of_4 {
	width: 23.5%;
}

/*  GO FULL WIDTH BELOW 480 PIXELS */
@media only screen and (max-width: 480px) {
	.col {  margin: 1% 0 1% 0%; }
	.span_1_of_4, .span_2_of_4, .span_3_of_4, .span_4_of_4 { width: 100%; }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<html lang="en" class="no-js">

<div id="picked"></div>
	<div class="section group">
		<div class="col span_1_of_4">
		    <input type="file" name="file_upload[]" id="file_upload" class="inputfile inputfile-2" data-multiple-caption="{count} files selected" multiple /><label id="fileLabel" for="file_upload"><svg xmlns="http://www.w3.org/2000/svg" width="20" height="17" viewBox="0 0 20 17"><path d="M10 0l-5.2 4.9h3.3v5.1h3.8v-5.1h3.3l-5.2-4.9zm9.3 11.5l-3.2-2.1h-2l3.4 2.6h-3.5c-.1 0-.2.1-.2.1l-.8 2.3h-6l-.8-2.2c-.1-.1-.1-.2-.2-.2h-3.6l3.4-2.6h-2l-3.2 2.1c-.4.3-.7 1-.6 1.5l.6 3.1c.1.5.7.9 1.2.9h16.3c.6 0 1.1-.4 1.3-.9l.6-3.1c.1-.5-.2-1.2-.7-1.5z"/></svg><span>CHOOSE A FILE</span></label>
		</div>
		<div class="col span_3_of_4">
		    <canvas width="600" height="300" id="canvas_picker"></canvas>
		</div>
	</div>
  
  <html/>

使用标签标记

1 个答案: