dtkvlj5386 2019-03-20 21:15
浏览 817
已采纳

图像(Blob)在浏览器中只显示一次

I'm using Symfony2 and Twig:

In the Entity Class

/**
 * @ORM\Column(name="photo", type="blob", nullable=true)
 */
private $photo;

// ...

public function displayPhoto()
{
    return "data:image/png;base64," . base64_encode(stream_get_contents($this->getPhoto()));
}

In the view

<img src="{{ entity.displayPhoto }}">

But if I write

<img src="{{ entity.displayPhoto }}">
<img src="{{ entity.displayPhoto }}">

Then the browser display it only the first time. In the browser (Firefox) The DOM looks like this:

<img src="data:image/png;base64,/9j/4QS...//much more chars//...f7R+ooYz//Z">
<img src="data:image/png;base64,">

So the image content is not present in the second img tag.

Any idea how to show the image more than once?

  • 写回答

1条回答 默认 最新

  • douniao7308 2019-03-20 22:30
    关注

    You will need to either rewind your stream

    /**
     * @ORM\Column(name="photo", type="blob", nullable=true)
     */
    private $photo;
    
    public function displayPhoto()
    {
        rewind($this->getPhoto());
        return "data:image/png;base64," . base64_encode(stream_get_contents($this->getPhoto()));
    }
    

    Or maybe better for performance, have a property storing the raw content of the blob:

    /**
     * @ORM\Column(name="photo", type="blob", nullable=true)
     */
    private $photo;
    
    private $rawPhoto;
    
    public function displayPhoto()
    {
        if(null === $this->rawPhoto) {
            $this->rawPhoto = "data:image/png;base64," . base64_encode(stream_get_contents($this->getPhoto()));
        }
    
        return $this->rawPhoto;
    }
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥15 file converter 转换格式失败 报错 Error marking filters as finished,如何解决?
  • ¥15 ubuntu系统下挂载磁盘上执行./提示权限不够
  • ¥15 Arcgis相交分析无法绘制一个或多个图形
  • ¥15 关于#r语言#的问题:差异分析前数据准备,报错Error in data[, sampleName1] : subscript out of bounds请问怎么解决呀以下是全部代码:
  • ¥15 seatunnel-web使用SQL组件时候后台报错,无法找到表格
  • ¥15 fpga自动售货机数码管(相关搜索:数字时钟)
  • ¥15 用前端向数据库插入数据,通过debug发现数据能走到后端,但是放行之后就会提示错误
  • ¥30 3天&7天&&15天&销量如何统计同一行
  • ¥30 帮我写一段可以读取LD2450数据并计算距离的Arduino代码
  • ¥15 飞机曲面部件如机翼,壁板等具体的孔位模型