如何使用 imagestring 函数在图像上添加日期和时间戳？

gitbox 2025-09-18
<span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 这是文章前面的PHP部分，与正文内容无关</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"欢迎阅读本篇教程！"</span></span><span>;
</span><span><span class="hljs-meta">?&gt;</span></span><span>

&lt;hr&gt;

</span><span><span class="hljs-meta">&lt;?php</span></span><span>
<span class="hljs-comment">/*
标题：如何使用 imagestring 函数在图像上添加日期和时间戳？
*/</span>

</span><span><span class="hljs-comment">// 在PHP中，imagestring函数可以用于在图像上绘制简单的文本。</span></span><span>
</span><span><span class="hljs-comment">// 我们可以结合date函数获取当前日期和时间，并将其写入图像。</span></span><span>

</span><span><span class="hljs-comment">// 1. 创建一个空白图像</span></span><span>
</span><span><span class="hljs-variable">$width</span></span><span> = </span><span><span class="hljs-number">400</span></span><span>;
</span><span><span class="hljs-variable">$height</span></span><span> = </span><span><span class="hljs-number">100</span></span><span>;
</span><span><span class="hljs-variable">$image</span></span><span> = </span><span><span class="hljs-title function_ invoke__">imagecreatetruecolor</span></span><span>(</span><span><span class="hljs-variable">$width</span></span><span>, </span><span><span class="hljs-variable">$height</span></span><span>);

</span><span><span class="hljs-comment">// 2. 分配颜色</span></span><span>
</span><span><span class="hljs-variable">$background_color</span></span><span> = </span><span><span class="hljs-title function_ invoke__">imagecolorallocate</span></span><span>(</span><span><span class="hljs-variable">$image</span></span><span>, </span><span><span class="hljs-number">255</span></span><span>, </span><span><span class="hljs-number">255</span></span><span>, </span><span><span class="hljs-number">255</span></span><span>); </span><span><span class="hljs-comment">// 白色背景</span></span><span>
</span><span><span class="hljs-variable">$text_color</span></span><span> = </span><span><span class="hljs-title function_ invoke__">imagecolorallocate</span></span><span>(</span><span><span class="hljs-variable">$image</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>); </span><span><span class="hljs-comment">// 黑色文字</span></span><span>

</span><span><span class="hljs-comment">// 3. 填充背景</span></span><span>
</span><span><span class="hljs-title function_ invoke__">imagefilledrectangle</span></span><span>(</span><span><span class="hljs-variable">$image</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-variable">$width</span></span><span>, </span><span><span class="hljs-variable">$height</span></span><span>, </span><span><span class="hljs-variable">$background_color</span></span><span>);

</span><span><span class="hljs-comment">// 4. 获取当前日期和时间</span></span><span>
</span><span><span class="hljs-variable">$timestamp</span></span><span> = </span><span><span class="hljs-title function_ invoke__">date</span></span><span>(</span><span><span class="hljs-string">'Y-m-d H:i:s'</span></span><span>);

</span><span><span class="hljs-comment">// 5. 在图像上添加日期和时间</span></span><span>
</span><span><span class="hljs-comment">// 参数解释：图像、字体大小（1-5）、X坐标、Y坐标、文本内容、颜色</span></span><span>
</span><span><span class="hljs-title function_ invoke__">imagestring</span></span><span>(</span><span><span class="hljs-variable">$image</span></span><span>, </span><span><span class="hljs-number">5</span></span><span>, </span><span><span class="hljs-number">10</span></span><span>, </span><span><span class="hljs-number">40</span></span><span>, </span><span><span class="hljs-variable">$timestamp</span></span><span>, </span><span><span class="hljs-variable">$text_color</span></span><span>);

</span><span><span class="hljs-comment">// 6. 输出图像到浏览器</span></span><span>
</span><span><span class="hljs-title function_ invoke__">header</span></span><span>(</span><span><span class="hljs-string">'Content-Type: image/png'</span></span><span>);
</span><span><span class="hljs-title function_ invoke__">imagepng</span></span><span>(</span><span><span class="hljs-variable">$image</span></span><span>);

</span><span><span class="hljs-comment">// 7. 释放图像内存</span></span><span>
</span><span><span class="hljs-title function_ invoke__">imagedestroy</span></span><span>(</span><span><span class="hljs-variable">$image</span></span><span>);

<span class="hljs-comment">/*
说明：
- imagestring适合绘制简单文字，如果需要更多字体样式，可以使用imagettftext。
- X和Y坐标可以根据图像大小调整，以确保文字显示在合适位置。
- date函数可以自定义格式，例如 'Y-m-d H:i:s' 显示完整日期和时间。
*/</span>

</span><span><span class="hljs-meta">?&gt;</span></span><span>

</span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 这是文章尾部的PHP部分，与正文内容无关</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"文章结束，感谢阅读！"</span></span><span>;
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>
imagestring