Question

所以我试图做一个简单的函数来淡入和淡出UIElement 出现的问题是该元素逐渐淡化并具有1的不透明度，但是在淡出时，不透明度在大约0.01处变为0相对结束。

        public static async Task<bool> FadeIO(UIElement target, int FadeTime = 100, int DelayBeforeFade = 5000, int DelayBeforeOutFade = 10000)
    {
        double OpacTick = 0; //The "counter" for the while loops.
        double FadeAmount = ((double)1 / FadeTime); //Calculates the required opacity increment for the fade to happen in the specified time.
        await Task.Delay(DelayBeforeFade); //Holds until the required delay before the fade has been reached.
        do
        {
            target.Opacity = 0 + OpacTick; //Alters the target's opacity based on the current loop cylce.
            OpacTick += FadeAmount; //Alters the counter by the pre calculated alteration amount.
            await Task.Delay(1); //Halts the loop

        } while (OpacTick <= 1); //Loops finished when the target's opacity is 1.
        OpacTick = 0; //Resets the loop counter.
        await Task.Delay(DelayBeforeOutFade); //Holds until the required delay before the fade out has been reached
        do
        {
            target.Opacity = 1 - OpacTick; //Alters the target's opacity based on the current loop cylce.
            OpacTick += FadeAmount; //Alters the counter by the pre calculated alteration amount.
            await Task.Delay(1); //Halts the loop

        } while (OpacTick <= 1); //Loops finished when the target's opacity is 0 and the counter is therefor 1.
        return true;
    }

这个问题最奇怪的是，在不同的系统上进行测试时，不透明度可以完全恢复为0，而在某些系统上，不透明度可以达到大约0.01

Answer 1

最后一次循环迭代不会使您达到0：

将不透明度设置为〜0.01，然后然后递增OpacTick，然后将其与1进行检查。它实际上从未将不透明度设置为递增量。

话虽如此，这完全是不必要的。 DoubleAnimationUsingKeyFrames可以为您提供更好的服务。

C＃Wpf不透明度不恢复为0

1 个答案: