相关疑难解决方法(0)

我试图复制我的设计师为应用程序所做的登录屏幕设计.

背景图像使用了softLight的blendMode,其结果是它与之混合的颜色是渐变颜色.其次,实际上有两层不同的渐变(一个紫色渐变,一个蓝色渐变)

原始图片:

最终的渐变图像

现在我尝试使用colorBlendMode,例如

Image.asset(
      'assets/pioneer-party.jpg',
      fit: BoxFit.cover,
      color: Color(0xff0d69ff).withOpacity(1.0),
      colorBlendMode: BlendMode.softLight,
    ),

问题是颜色属性只需要一种颜色.

然后我尝试了BoxDecoration,例如

DecoratedBox(
      decoration: new BoxDecoration(
        color: const Color(0xff7c94b6),
        image: new DecorationImage(
          fit: BoxFit.cover,
          colorFilter: new ColorFilter.mode(Colors.purple.withOpacity(1.0), BlendMode.softLight),
          image: new NetworkImage(
            'http://www.allwhitebackground.com/images/2/2582-190x190.jpg',
          ),
        ),
      ),
    ),

这仍然让我遇到同样的问题.然后,我尝试单独堆叠每个图层,然后使用渐变来使其看起来接近设计,例如

Image.asset(
      'assets/pioneer-party.jpg',
      fit: BoxFit.cover,
      color: Color(0xff0d69ff).withOpacity(1.0),
      colorBlendMode: BlendMode.softLight,
    ),
    DecoratedBox(
      decoration: BoxDecoration(
        gradient: LinearGradient(
          begin: FractionalOffset.topCenter,
          end: FractionalOffset.bottomCenter,
          colors: [
            Color(0xff0d69ff).withOpacity(0.0),
            Color(0xff0069ff).withOpacity(0.8),
          ],
        ),
      ),
    ),
    DecoratedBox(
      decoration: BoxDecoration(
        gradient: LinearGradient(
          begin: FractionalOffset.topLeft,
          end: FractionalOffset.bottomRight,
          colors: [
            Color(0xff692eff).withOpacity(0.8),
            Color(0xff642cf4).withOpacity(0.8), …

有没有一种方法可以使图像逐渐淡出底部？因此，图像底部的透明度为0。

我需要图像是透明的，不能使用堆栈在底部用颜色覆盖图像，因为我不知道图像的底下是什么。

这是我的形象

            Container(
              decoration: BoxDecoration(
                image: DecorationImage(
                  fit: BoxFit.cover,
                  colorFilter: new ColorFilter.mode(Colors.black.withOpacity(1), BlendMode.dstATop),
                  image: NetworkImage(
                    routine.thumbnail
                  )
                )
              ),
            )

我不能这样做：

        background: Stack(
          alignment: AlignmentDirectional.bottomCenter,                        
          children: <Widget>[
            Container(
              decoration: BoxDecoration(
                image: DecorationImage(
                  fit: BoxFit.cover,
                  image: NetworkImage(
                    routine.thumbnail,
                  )
                )
              ),
            ),
            Container(
              width: 1000,
              height: 100,
              decoration: BoxDecoration(
                gradient: LinearGradient(
                  begin: FractionalOffset.topCenter,
                  end: FractionalOffset.bottomCenter,
                  colors: [
                    Colors.transparent,
                    someColor // I don't know what Color this will be, so I can't use this
                  ]
                )
              ),
            ),
          ]
        ),