context.onCameraFrame((frame) => {

try {

if (!this.data.flag) {

return;

}

wx.canvasPutImageData({

canvasId: ‘myCanvas’,

x: 0,

y: 0,

width: frame.width,

heihgt: frame.height,

data: new Uint8ClampedArray(frame.data),

success(res) {

wx.showModal({

title: ‘获取图片’,

content: ‘’ + res,

})

},

fail(err){

wx.showModal({

title: ‘获取图片失败’,

content: ‘’ + err.errMsg,

})

}

});

}catch(err){

}

});

报错信息：canvasPutImageData:fail canvas is empty