MrFant/h5_file_demo.html

## h5_file_demo.html
<html>
<head>
  <meta charset="UTF-8">
  <title>File API</title>
</head>
<body>

<article>
  <div id="holder"></div>
  <p id="status">File API & FileReader API not supported</p>
  <p>Drag an image from your desktop on to the drop zone above to see the browser read the contents of the file and use it as the background - without uploading the file to any servers.</p>
</article>

<style>
#holder { border: 10px dashed #ccc; width: 300px; height: 300px; margin: 20px auto;}
#holder.hover { border: 10px dashed #333; }
</style>

<script>
var holder = document.getElementById('holder'),
    state = document.getElementById('status');

if (typeof window.FileReader === 'undefined') {
  state.className = 'fail';
} else {
  state.className = 'success';
  state.innerHTML = 'File API & FileReader available';
}

holder.ondragover = function () { this.className = 'hover'; return false; };
holder.ondragend = function () { this.className = ''; return false; };
holder.ondrop = function (e) {
  this.className = '';
  e.preventDefault();

  var file = e.dataTransfer.files[0],
      reader = new FileReader();
  reader.onload = function (event) {
    console.log(event.target);
    holder.style.background = 'url(' + event.target.result + ') no-repeat center';
  };
  console.log(file);
  reader.readAsDataURL(file);

  return false;
};
</script>

</body>
</html>

## image_upload_preview.html
<!--
/**
 * html5 file api实例
 * input type=file 时，会显示一个choose Files的按钮，按钮旁是一段描述，这个显示效果的原理暂不明了。
 * 当input标签设置了multiple属性时，可以上传多个文件，所以在获取file引用时需要加上[0].
 * FileReader() api 待了解。。。
 *
 *
 */
-->
<!DOCTYPE html>
<html>
<head>
    <title>untitled</title>
</head>
<body>
<form method="post" action="http://localhost/test" enctype="multipart/form-data">
    <p>图片预览：</p>
    <p>
    <div id="test-image-preview"
         style="border: 1px solid #ccc; width: 100%; height: 200px; background-size: contain; background-repeat: no-repeat; background-position: center center;"></div>
    </p>
    <p>
        <input type="file" multiple id="test-image-file" name="test">
    </p>
    <p id="test-file-info"></p>
</form>

<script>
    var
        fileInput = document.getElementById('test-image-file'),
        info = document.getElementById('test-file-info'),
        preview = document.getElementById('test-image-preview');
        // 监听change事件:
        fileInput.addEventListener('change', function () {
            // 清除背景图片:
            preview.style.backgroundImage = '';
            // 检查文件是否选择:
            if (!fileInput.value) {
                info.innerHTML = '没有选择文件';
                return;
            }
            // 获取File引用:
            var file = fileInput.files[0];
            // 获取File信息:
            info.innerHTML =
                '文件: ' + file.name + '<br>' +
                '大小: ' + file.size + '<br>' +
                '修改: ' + file.lastModifiedDate;
            if (file.type !== 'image/jpeg' && file.type !== 'image/png' && file.type !== 'image/gif') {
                alert('不是有效的图片文件!');
                return;
            }
            // 读取文件:
            var reader = new FileReader();
            reader.onload = function (e) {
                var
                    data = e.target.result; // 'data:image/jpeg;base64,/9j/4AAQSk...(base64编码)...'
                preview.style.backgroundImage = 'url(' + data + ')';
            };
            // 以DataURL的形式读取文件:
            reader.readAsDataURL(file);
        });
</script>


</body>
</html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title>File API</title>
	</head>
	<body>

	<article>
	<div id="holder"></div>
	<p id="status">File API & FileReader API not supported</p>
	<p>Drag an image from your desktop on to the drop zone above to see the browser read the contents of the file and use it as the background - without uploading the file to any servers.</p>
	</article>

	<style>
	#holder { border: 10px dashed #ccc; width: 300px; height: 300px; margin: 20px auto;}
	#holder.hover { border: 10px dashed #333; }
	</style>

	<script>
	var holder = document.getElementById('holder'),
	state = document.getElementById('status');

	if (typeof window.FileReader === 'undefined') {
	state.className = 'fail';
	} else {
	state.className = 'success';
	state.innerHTML = 'File API & FileReader available';
	}

	holder.ondragover = function () { this.className = 'hover'; return false; };
	holder.ondragend = function () { this.className = ''; return false; };
	holder.ondrop = function (e) {
	this.className = '';
	e.preventDefault();

	var file = e.dataTransfer.files[0],
	reader = new FileReader();
	reader.onload = function (event) {
	console.log(event.target);
	holder.style.background = 'url(' + event.target.result + ') no-repeat center';
	};
	console.log(file);
	reader.readAsDataURL(file);

	return false;
	};
	</script>

	</body>
	</html>
	<!--
	/**
	* html5 file api实例
	* input type=file 时，会显示一个choose Files的按钮，按钮旁是一段描述，这个显示效果的原理暂不明了。
	* 当input标签设置了multiple属性时，可以上传多个文件，所以在获取file引用时需要加上[0].
	* FileReader() api 待了解。。。
	*
	*
	*/
	-->
	<!DOCTYPE html>
	<html>
	<head>
	<title>untitled</title>
	</head>
	<body>
	<form method="post" action="http://localhost/test" enctype="multipart/form-data">
	<p>图片预览：</p>
	<p>
	<div id="test-image-preview"
	style="border: 1px solid #ccc; width: 100%; height: 200px; background-size: contain; background-repeat: no-repeat; background-position: center center;"></div>
	</p>
	<p>
	<input type="file" multiple id="test-image-file" name="test">
	</p>
	<p id="test-file-info"></p>
	</form>

	<script>
	var
	fileInput = document.getElementById('test-image-file'),
	info = document.getElementById('test-file-info'),
	preview = document.getElementById('test-image-preview');
	// 监听change事件:
	fileInput.addEventListener('change', function () {
	// 清除背景图片:
	preview.style.backgroundImage = '';
	// 检查文件是否选择:
	if (!fileInput.value) {
	info.innerHTML = '没有选择文件';
	return;
	}
	// 获取File引用:
	var file = fileInput.files[0];
	// 获取File信息:
	info.innerHTML =
	'文件: ' + file.name + '<br>' +
	'大小: ' + file.size + '<br>' +
	'修改: ' + file.lastModifiedDate;
	if (file.type !== 'image/jpeg' && file.type !== 'image/png' && file.type !== 'image/gif') {
	alert('不是有效的图片文件!');
	return;
	}
	// 读取文件:
	var reader = new FileReader();
	reader.onload = function (e) {
	var
	data = e.target.result; // 'data:image/jpeg;base64,/9j/4AAQSk...(base64编码)...'
	preview.style.backgroundImage = 'url(' + data + ')';
	};
	// 以DataURL的形式读取文件:
	reader.readAsDataURL(file);
	});
	</script>


	</body>
	</html>