What should I do if the php verification code cannot be displayed?

The solution to the problem that the php verification code cannot be displayed: first open the corresponding code file; then add the code "ob_clean();" before the header output to solve the problem of the verification code not being displayed.

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PHP verification code image cannot be displayed problem

I thought the gd2 library was not open, but I checked it with phpinfo and found that it was open

Solution

Add before the header output:

ob_clean (); //Key code to prevent the problem of 'the image cannot be displayed because of its own errors'.

header("Content-type:image/jpeg");

Example:

  private function outPut() {
        ob_clean();  //关键代码，防止出现'图像因其本身有错无法显示'的问题。
        header('Content-type:image/png');
        imagepng($this->img);
        imagedestroy($this->img);
    }

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