将按钮对齐到 CardView 的底部

问题描述

所以我在 for 循环中创建了一些 CardView，我想在每个 CardView 的底部添加一个 Button。

我像这样设置 CardView 的 LayoutParams

RelativeLayout.LayoutParams params4 = new RelativeLayout.LayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT,height
            );
cardview.setLayoutParams(params4);

并为按钮创建一组新的参数

RelativeLayout.LayoutParams params20 = new RelativeLayout.LayoutParams(
                    RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT
            );

像这样添加对齐到底部的规则，然后将这些参数设置为按钮的 LayoutParams

params20.addRule(RelativeLayout.ALIGN_PARENT_BottOM);
search.setLayoutParams(params20);

最后我将 Button 添加到 CardView

cardView.addView(search);

但是这样做按钮总是保持在顶部。当记录 CardViews 和 Button 的父级时，父级是当前 CardView

使用 2 个 CardView 登录：

2021-01-27 10:15:45.843 7764-7764/lenno.plugin.smartplaner E/deine: cardview: androidx.cardview.widget.CardView{d12f026 VFE...CL. ......I. 0,0-0,0 #1}........id: 1
2021-01-27 10:15:45.843 7764-7764/lenno.plugin.smartplaner E/deine1: parent: androidx.cardview.widget.CardView{d12f026 VFE...CL. ......I. 0,0 #1}
2021-01-27 10:15:45.855 7764-7764/lenno.plugin.smartplaner E/deine: cardview: androidx.cardview.widget.CardView{ee5dc0a VFE...CL. ......I. 0,0 #2}........id: 2
2021-01-27 10:15:45.856 7764-7764/lenno.plugin.smartplaner E/deine1: parent: androidx.cardview.widget.CardView{ee5dc0a VFE...CL. ......I. 0,0 #2}

我已经尝试过像这样将 params20 的锚点显式设置为父 CardView

params20.addRule(RelativeLayout.ALIGN_PARENT_BottOM,cardView.getId());

也没有用。也许我在一般情况下做错了什么（我刚刚开始以编程方式创建布局）但我目前不知道该怎么做。

提前感谢您的回答！

解决方法

这里有一个例子。阅读评论以获取信息。

public class MainActivity extends Activity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.main);
        
        //CardView
        CardView cardview = new CardView(this);
        cardView.setId(1);
        RelativeLayout.LayoutParams params4 = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,1000);
        cardview.setLayoutParams(params4);

        //Button
        Button btn1 = new Button(this);
        btn1.setText("Button at the bottom");
        btn1.setId(2); //Only needed you wanna put another view close to this view. See below.
        RelativeLayout.LayoutParams params20 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
        params20.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM,1 /* ID of cardView */); //This will cause this view (button) to be positioned at the bottom of parent view.
        
        //Add the Button to the CardView. Make sure to include the layout params too.
        cardview.addView(btn1,params20);
        
        //If you wanna add another view above btn1,here's how.
        Button btn2 = new Button(this);
        btn2.setText("I'm above button one");
        RelativeLayout.LayoutParams params21 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
        params21.addRule(RelativeLayout.ABOVE,2 /* ID of btn1 */);
        
        //Add btn2 to the CardView.
        cardview.addView(btn2,params21);
        
        //Main layout
        setContentView(cardview);
    }
}

,

我仍然不知道最初的问题是什么，但我通过对 Button 使用 ConstraintLayout 并将 topMargin 设置为合适的值来修复它。

ConstraintLayout.LayoutParams params20 = new ConstraintLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
params20.topMargin = 850;

search.setLayoutParams(params20);
cardView.addView(search);