新增了预览效果

Author: DianWoung

README.md

@@ -27,4 +27,10 @@ Encore\Admin\Form::extend('largefile', \Encore\LargeFileUpload\LargeFileField::c
 $form->largefile('ColumnName', 'LabelName');
 ````
 效果如图：
-![](data:image/png;base64,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)
+
+基本样式
+
+![](preview.png)
+
+上传中
+![](onload.png)