使用ConstraintSet实现布局控件动画

话不多说,直接上代码

MainActivity.class

    private ConstraintSet constraintSet1;
    private ConstraintSet constraintSet2;
    ConstraintLayout constraintLayout;
    boolean old = true;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityMain1Binding binding = DataBindingUtil.setContentView(this, R.layout.activity_main1);
        constraintLayout = (ConstraintLayout) binding.getRoot();
        constraintSet1 = new ConstraintSet();
        constraintSet1.clone(constraintLayout);
        constraintSet2 = new ConstraintSet();
        constraintSet2.clone(this,R.layout.activity_main2);
        binding.setOnClick(this);
    }

    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    public void onClick(View v) {
        TransitionManager.beginDelayedTransition(constraintLayout);
        if (old = !old){
            constraintSet1.applyTo(constraintLayout);
        }else{
            constraintSet2.applyTo(constraintLayout);
        }
    }

activity_main1.xml

activity_main2.xml

最后总结下几个注意事项:
constrainset , 动画基于布局文件,需要两个约束位置不同的布局

1. 根布局必须为constrainlayout

2. 子view都必须有id

3. 动画只支持 约束条件的变化,view的属性修改无效,像text view的字体大小,颜色.

4. 动画布局可以只包含要做动画的布局,其他可以舍弃(activity_main1比activity_main2多了一个image view)

   github 地址