如何改变NumberPicker的价值与动画? [英] How to change NumberPicker's value with animation?
问题描述
我已经为Android的应用程序,其中有一个NumberPicker。我需要改变这个NumberPicker的价值,但有一个流畅的动画效果,当你触摸它像并改变它的值。
I've created an application for Android, in which there is a NumberPicker. And I need to change the value of this NumberPicker but with a smooth animation like when you touch it and change its value.
例如,假定当前值是1,这将是5,我希望NumberPicker自旋为1〜2,然后以3等等。但我想它旋转不只是瞬间改变的值!
For example, assume the current value is 1 and it's going to be 5, I want the NumberPicker to spin from 1 to 2 then to 3 and so on. But I want it to spin not just instantly change the values!
如果我用下面的code:
If I use the following code:
numberPicker.setValue(5);
它的值将立即改变到5,但我想它从1卷起至5就像当你手动触摸它,使之旋转。
its value will instantly change to 5, but I want it to roll up from 1 to 5 like when you manually touch it and make it spin.
推荐答案
我通过refelction解决它
I solved it via refelction
/**
* using reflection to change the value because
* changeValueByOne is a private function and setValue
* doesn't call the onValueChange listener.
*
* @param higherPicker
* the higher picker
* @param increment
* the increment
*/
private void changeValueByOne(final NumberPicker higherPicker, final boolean increment) {
Method method;
try {
// refelction call for
// higherPicker.changeValueByOne(true);
method = higherPicker.getClass().getDeclaredMethod("changeValueByOne", boolean.class);
method.setAccessible(true);
method.invoke(higherPicker, increment);
} catch (final NoSuchMethodException e) {
e.printStackTrace();
} catch (final IllegalArgumentException e) {
e.printStackTrace();
} catch (final IllegalAccessException e) {
e.printStackTrace();
} catch (final InvocationTargetException e) {
e.printStackTrace();
}
}
运行完美。我不知道为什么这个方法是私有的
works perfect. I don't know why this method is private
这篇关于如何改变NumberPicker的价值与动画?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!