微信小游戏IOS用canvas.toTempFilePath截图保存然后分享，图片颜色显示问题

[nuagezok (芒果)]

window.shareCanvasImage = async (param, resultCb) => {

var jsonArray = JSON.parse(param)

canvas.toTempFilePath({

x: jsonArray.x,

y: jsonArray.y,

width: jsonArray.width,

height: jsonArray.height,

destWidth: jsonArray.destWidth,

destHeight: jsonArray.destHeight,

success(res) {

  wx.shareAppMessage({

    'title': '分享图片',

    'imageUrl': res,

    'type': jsonArray.type

  });

  resultCb && resultCb();

},

fail() {

  resultCb && resultCb();

}

});

}

IOS截图之后分享出去时显示的图片有问题