css如何制作加载

使用CSS制作加载动画

纯CSS旋转动画

通过@keyframes和transform属性创建一个简单的旋转加载动画：

.loader {
  width: 50px;
  height: 50px;
  border: 5px solid #f3f3f3;
  border-top: 5px solid #3498db;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

点状加载动画

创建三个跳动的圆点作为加载指示器：

.dot-loader {
  display: flex;
  justify-content: center;
  gap: 8px;
}

.dot {
  width: 12px;
  height: 12px;
  background-color: #3498db;
  border-radius: 50%;
  animation: bounce 1.4s infinite ease-in-out;
}

.dot:nth-child(2) {
  animation-delay: 0.2s;
}

.dot:nth-child(3) {
  animation-delay: 0.4s;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-15px); }
}

进度条加载动画

创建一个从左到右填充的进度条效果：

.progress-loader {
  width: 100%;
  height: 4px;
  background-color: #f3f3f3;
  position: relative;
  overflow: hidden;
}

.progress-loader::before {
  content: "";
  position: absolute;
  left: -50%;
  height: 100%;
  width: 50%;
  background-color: #3498db;
  animation: loading 2s linear infinite;
}

@keyframes loading {
  from { left: -50%; }
  to { left: 100%; }
}

骨架屏加载效果

为内容未加载时创建占位效果：

.skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

波浪形加载动画

创建类似波浪起伏的效果：

.wave-loader {
  display: flex;
  justify-content: center;
  gap: 6px;
  height: 40px;
}

.wave {
  width: 6px;
  height: 100%;
  background: linear-gradient(to top, #3498db, #2980b9);
  animation: wave 1s ease-in-out infinite;
}

.wave:nth-child(2) {
  animation-delay: 0.1s;
}

.wave:nth-child(3) {
  animation-delay: 0.2s;
}

.wave:nth-child(4) {
  animation-delay: 0.3s;
}

@keyframes wave {
  0%, 100% { height: 40%; }
  50% { height: 100%; }
}

这些CSS加载动画可以根据实际需求调整颜色、尺寸和动画时长。通过组合不同的动画属性和关键帧，可以创建各种视觉效果来指示加载状态。