Question

我想在java中为ConstraintLayout添加一些视图。这是布局xml：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/constraint_layout"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</android.support.constraint.ConstraintLayout>

这是活动的代码：

public class MainActivity extends AppCompatActivity {

    private ConstraintLayout layout;

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

        layout = (ConstraintLayout) findViewById(R.id.constraint_layout);
        TextView textView = new TextView(this);
        textView.setId(View.generateViewId());
        textView.setBackgroundColor(Color.RED);
        textView.setText("ciao");
        layout.addView(textView);

        ConstraintSet constraints = new ConstraintSet();
        constraints.clone(layout);
        constraints.constrainWidth(textView.getId(), ConstraintSet.MATCH_CONSTRAINT);
        constraints.constrainHeight(textView.getId(), ConstraintSet.MATCH_CONSTRAINT);
        constraints.setDimensionRatio(textView.getId(), "h,1:1");
        constraints.connect(textView.getId(), ConstraintSet.LEFT, ConstraintSet.PARENT_ID, ConstraintSet.LEFT, 8);
        constraints.connect(textView.getId(), ConstraintSet.RIGHT, ConstraintSet.PARENT_ID, ConstraintSet.RIGHT, 8);
        constraints.connect(textView.getId(), ConstraintSet.TOP, ConstraintSet.PARENT_ID, ConstraintSet.TOP, 8);
        constraints.applyTo(layout);
    }
}

左边和右边的约束边距（参见连接调用）被简单地忽略。我正在使用sdk的第25版。这是一个错误吗？或者我做错了什么？ The TextView without left and right margin

Answer 1

如您指定的那样设置左右边距绝对可以正常工作。为什么它对我来说仍然不是一个谜。作为解决方法，您可以在TextView上明确设置边距，如下所示：

ConstraintLayout.LayoutParams params =
        new ConstraintLayout.LayoutParams(ConstraintLayout.LayoutParams.MATCH_CONSTRAINT,
        ConstraintLayout.LayoutParams.MATCH_CONSTRAINT);
params.setMargins(8,8,8,8);
textView.setLayoutParams(params);

向ConstraintLayout中的视图添加约束会忽略左右边距

1 个答案: