java - Android TextView 中的动画背景颜色

Question

有谁知道为什么这段代码不起作用以及如何修复它？我正在尝试将 TextView 的背景颜色设置为动画。 IDE 不显示错误。

private void animationButton(final TextView textView) {

    int firstColor = Color.parseColor("FFFFFFFF");
    int secondColor = Color.parseColor("FF00FF00");

    ValueAnimator animation = new ValueAnimator();
    animation.setIntValues(firstColor, secondColor);
    animation.setEvaluator(new ArgbEvaluator());

    animation.setDuration(300);

    animation.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            textView.setBackgroundColor((int) animation.getAnimatedValue());
        }
    });

    animation.start();
}

Answer 1

IDE doesn't show error

然后我假设您将 animationButton 包围在 try-catch block 中，并且没有记录任何内容，因为 Color.parseColor需要 # 来解析十六进制颜色代码。您发布的代码应该会收到 IllegalArgumentException 。

来自文档

Parse the color string, and return the corresponding color-int. If the string cannot be parsed, throws an IllegalArgumentException exception. Supported formats are:

#RRGGBB

#AARRGGBB

否则您需要传入以下值之一:

red, blue, green, black, white, gray, cyan, magenta, yellow, lightgray, darkgray, grey, lightgrey, darkgrey, aqua, fuchsia, lime, maroon, navy, olive, purple, silver, and teal.

来源

@ColorInt
public static int parseColor(@Size(min=1) String colorString) {
    if (colorString.charAt(0) == '#') {
        // Use a long to avoid rollovers on #ffXXXXXX
        long color = Long.parseLong(colorString.substring(1), 16);
        if (colorString.length() == 7) {
            // Set the alpha value
            color |= 0x00000000ff000000;
        } else if (colorString.length() != 9) {
            throw new IllegalArgumentException("Unknown color");
        }
        return (int)color;
    } else {
        Integer color = sColorNameMap.get(colorString.toLowerCase(Locale.ROOT));
        if (color != null) {
            return color;
        }
    }
    throw new IllegalArgumentException("Unknown color");
}