;
                    mediaElement.className = 'unsupported-media';
                    mediaElement.innerHTML = `<p>不支持的媒体类型</p><span>${mimeType}</span>`;
                }
                
                if (mediaElement.tagName !== 'DIV') {
                    mediaElement.src = `${mimeType}base64,${base64Key}`;
                }

                mediaElement.onerror = function() {
                    this.alt = '预览失败';
                    this.style.display = 'none';
