uniapp usb摄像头悬浮窗
时间: 2023-12-09 15:36:21 浏览: 157
根据提供的引用[1],在HBuilderX 2.0.0 alpha版本中,uni-app新增了uni.requestVideoFrame和uni.createCameraContext两个API,可以实现USB摄像头悬浮窗的功能。具体步骤如下:
1.在manifest.json文件中添加权限声明:
```json
"android": {
"permission": [
"android.permission.CAMERA",
"android.permission.RECORD_AUDIO"
]
}
```
2.在页面中创建一个canvas元素,并设置宽高和定位:
```html
<canvas id="camera" style="width: 100%; height: 100%; position: fixed; top: 0; left: 0;"></canvas>
```
3.在页面的onLoad生命周期函数中获取cameraContext对象,并调用startPreview方法:
```javascript
onLoad() {
this.cameraContext = uni.createCameraContext();
this.cameraContext.startPreview(this.$refs.camera);
}
```
4.在页面的onReady生命周期函数中创建一个定时器,每隔一段时间调用requestVideoFrame方法获取摄像头的画面,并将画面绘制到canvas上:
```javascript
onReady() {
setInterval(() => {
this.cameraContext.requestVideoFrame({
width: 640,
height: 480,
quality: 'medium',
format: 'yuv'
}, (data) => {
const canvas = this.$refs.camera;
const ctx = canvas.getContext('2d');
const imgData = new ImageData(new Uint8ClampedArray(data.data), data.width, data.height);
ctx.putImageData(imgData, 0, 0);
});
}, 1000 / 30);
}
```
5.最后,记得在页面销毁时调用stopPreview方法停止预览:
```javascript
onUnload() {
this.cameraContext.stopPreview();
}
```
阅读全文