<camera class=‘camera’ mode=“scanCode”   bindinitdone = “onCameraInitDone”  binderror=“onCameraError”   bindscancode=“onScancodeResult”  style=“width: 100%; height: 300px;”>

<cover-view class=‘mark’></cover-view>

</camera>

.camera{

position: relative;

}

.mark{

margin:80rpx;

border:10rpx solid #006600;

height:200px;

}

大概就这样，可以替换成图片