以下是使用Java代码将按钮设置到父视图底部的示例:
ConstraintLayout constraintLayout;
ConstraintSet constraintSet;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
constraintLayout = (ConstraintLayout) findViewById(R.id.activity_main_constraint_layout);
Button button = new Button(this);
button.setText("Hello");
constraintLayout.addView(button);
constraintSet = new ConstraintSet();
constraintSet.clone(constraintLayout);
constraintSet.connect(button.getId(), ConstraintSet.LEFT, constraintLayout.getId(), ConstraintSet.RIGHT, 0);
constraintSet.constrainDefaultHeight(button.getId(), 200);
constraintSet.applyTo(constraintLayout);
}
要实现类似这样的效果:
app:layout_constraintLeft_toLeftOf="@+id/parent"
你的Java代码应该像这样
set.connect(YOURVIEW.getId(),ConstraintSet.LEFT,ConstraintSet.PARENT_ID,ConstraintSet.LEFT,0);
并且要实现类似这样的效果,
layout_constraintLeft_toRightOf="@+id/parent"
您的Java代码应该如下所示:
set.connect(YOURVIEW.getId(),ConstraintSet.LEFT,ConstraintSet.PARENT_ID,ConstraintSet.RIGHT,0);
在这里,我假设 android:id="@+id/parent"
是您的父级 ConstraintLayout 的ID。