Android 标题栏颜色渐变

标题栏渐变重点是监听Scrollview的滚动距离，所以重写了onScrollChanged方法监听滚动距离：

 

 

public class ChangeColorScrollview extends ScrollView{
    public ChangeColorScrollview(Context context) {
        super(context);
    }

    public ChangeColorScrollview(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public ChangeColorScrollview(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    private ScrollViewListener scrollViewListener = null;
    public interface ScrollViewListener {
        void onScrollChanged(ChangeColorScrollview scrollView, int x, int y,
                             int oldx, int oldy);
    }

    public void setScrollViewListener(ScrollViewListener scrollViewListener) {
        this.scrollViewListener = scrollViewListener;
    }

    @Override
    protected void onScrollChanged(int x, int y, int oldx, int oldy) {
        super.onScrollChanged(x, y, oldx, oldy);
        if (scrollViewListener != null) {
            scrollViewListener.onScrollChanged(this, x, y, oldx, oldy);
        }
    }

}

使用方法也很简单，直接加入如下代码：

 

 

 

 

scrollView.setScrollViewListener(new ChangeColorScrollview.ScrollViewListener() {
            @Override
            public void onScrollChanged(ChangeColorScrollview changeColorScrollview, int x, int y, int oldx, int oldy) {

                //改变标题栏颜色 y为欢动距离
                if (y <= 0) {
                    titleLinearLayout.setBackgroundColor(Color.argb((int) 0, 227, 29, 26));
                    titleLinearLayout.setAlpha((float) 0.7);
                } else if (y > 0 && y <= height) {
                    float scale = (float) y / height;
                    float alpha = (255 * scale);
                    // layout背景透明
                    titleLinearLayout.setBackgroundColor(Color.argb((int) alpha, 227, 29, 26));
                } else {
                    titleLinearLayout.setBackgroundColor(Color.argb((int) 255, 227, 29, 26));
                    titleLinearLayout.setAlpha(1);

                }
            }
        });

 

 

 

也直接可做回到顶部功能。