Android-如何使用crossfade动画更改状态栏颜色[复制]

Question

我想用crossfade动画实现颜色更改状态栏，如下所示。我能知道怎么做吗？

状态栏颜色更改动画：

谢谢！

编辑（2018年7月7日）-来吧，伙计们，这不是复制品

不管怎样，最后我找到了一个解决方案，使用ValueAnimator和Argb评估器。

val mColorAnimation = ValueAnimator.ofObject(ArgbEvaluator(), firstColor, secondColor, thirdColor, fourthColor) 

mColorAnimation.duration = (pageCount - 1) * 10000000000L

mColorAnimation.addUpdateListener { animator ->
    val color = animator.animatedValue as Int

    // change status, navigation, and action bar color
    window.statusBarColor = color
    window.navigationBarColor = color
    supportActionBar?.setBackgroundDrawable(ColorDrawable(color))
}

main_viewpager.addOnPageChangeListener(object : ViewPager.OnPageChangeListener{
    override fun onPageScrollStateChanged(state: Int) { /* unused */ }
    override fun onPageSelected(position: Int) { /* unused */ }

    override fun onPageScrolled(position: Int, positionOffset: Float, positionOffsetPixels: Int) {
        mColorAnimation.currentPlayTime = ((positionOffset + position) * 10000000000).toLong()
    }
})

Answer 1

这就是如何以编程方式更改状态栏的颜色。现在，您可以在ViewPagerlistener中更改状态栏的颜色。

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    Window window = getWindow();
    window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
    window.setStatusBarColor(Color.RED);
}

Answer 2

github上已经有一个库，可以演示如何通过圆形显示效果对工具栏和状态栏的颜色进行动画更改。看看这个。

这是代码片段

public class MainActivity extends Activity {

    private View mRevealView;
    private View mRevealBackgroundView;
    private Toolbar mToolbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mToolbar = (Toolbar) findViewById(R.id.appbar);
        mToolbar.setTitle(getString(R.string.app_name));

        mRevealView = findViewById(R.id.reveal);
        mRevealBackgroundView = findViewById(R.id.revealBackground);

        ToggleButton toggleButton = (ToggleButton) findViewById(R.id.toggleButton);
        toggleButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                boolean on = ((ToggleButton) v).isChecked();

                if (on) {
                    animateAppAndStatusBar(R.color.primary, R.color.accent);
                } else {
                    animateAppAndStatusBar(R.color.accent, R.color.primary);
                }
            }
        });

        setActionBar(mToolbar);
    }

    private void animateAppAndStatusBar(int fromColor, final int toColor) {
        Animator animator = ViewAnimationUtils.createCircularReveal(
                mRevealView,
                mToolbar.getWidth() / 2,
                mToolbar.getHeight() / 2, 0,
                mToolbar.getWidth() / 2);

        animator.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationStart(Animator animation) {
                mRevealView.setBackgroundColor(getResources().getColor(toColor));
            }
        });

        mRevealBackgroundView.setBackgroundColor(getResources().getColor(fromColor));
        animator.setStartDelay(200);
        animator.setDuration(125);
        animator.start();
        mRevealView.setVisibility(View.VISIBLE);
    }
}

希望有帮助。