java - 从数组android studio动态生成按钮

Question

我正在尝试编写一种方法，该方法使用从名称和 ID 的二维数组获取的数据生成按钮，如果运行两次，该函数应该在已生成的按钮之后添加更多按钮。这些按钮将添加到约束布局(使用作为 Activity XML 一部分的准则 18 和 19)。

我正在使用全局按钮列表来存储已生成的按钮

List<Button> contactButtonList = new ArrayList<>();

然后这是我编写的用于生成按钮并将它们附加到引导线的函数。

 void updateButtonList(String[][] contactsArray){

    //gets constraint layout
    ConstraintLayout layout = findViewById(R.id.mainConstraint);
    //creates constraint set
    ConstraintSet set = new ConstraintSet();

    //loops through array
    for(int i = 0; i < contactsArray.length; i++){

        //creates string to display on button
        String buttonText = contactsArray[i][0]+": "+contactsArray[i][1];
        //creates new button and sets ID based of size of list
        Button btn = new Button(this);
        btn.setId(contactButtonList.size());
        //sets button text from array
        btn.setText(buttonText);

        //adds the button to the layout
        layout.addView(btn,contactButtonList.size());

        //sets the constraint set to match the current layout.... i think?, this needs to be done after adding the view
        set.clone(layout);

        //connects button to left vert constraint
        set.connect(btn.getId(), ConstraintSet.LEFT, R.id.guideline19, ConstraintSet.RIGHT, 8);


        //if first button attaches to horz constraint else attaches to last button
        if(contactButtonList.isEmpty()){
            set.connect(btn.getId(), ConstraintSet.TOP, R.id.guideline18, ConstraintSet.BOTTOM, 8);
        }else{
            set.connect(btn.getId(), ConstraintSet.TOP, contactButtonList.get(contactButtonList.size() - 1).getId(), ConstraintSet.BOTTOM);
        }

        //adds button to list
        contactButtonList.add(btn);
    }

    //apply set to layout
    set.applyTo(layout);
}

抱歉，如果有点长，希望评论有所帮助。

无论如何，问题是只有数组中的最后一个按钮附加到指南，另外 2 个按钮仅出现在左上角。

例如使用此数组时。

 String[][] testArray = {{"a","123"},{"bill","245"},{"test","246"}};

输出看起来像(请忽略 TextView 和紫色按钮)。

当所有按钮都应该出现在彼此下方时。

我假设第一个按钮隐藏在左上角第二个按钮的后面。

Answer 1

找到了在 for 循环内移动 set.applyTo(layout) 的解决方案，我还将 btn.setId(contactButtonList.size()); 更改为 btn.setId(View.generateViewId()); 但我不确定这是否有助于解决问题。这是工作代码(注意我还添加了一些功能，但这些功能可以忽略)。

void updateButtonList(final String[][] contactsArray){

    //gets constraint layout
    ConstraintLayout layout = findViewById(R.id.mainConstraint);
    //creates constraint set
    ConstraintSet set = new ConstraintSet();

    //loops through array
    for(int i = 0; i < contactsArray.length; i++){

        //creates string to display on button
        String buttonText = contactsArray[i][0]+": "+contactsArray[i][1];
        //creates new button and sets ID based of size of list
        Button btn = new Button(this);

        //sets layout params width as 0 so we can set to match constraint
        btn.setLayoutParams(new ConstraintLayout.LayoutParams(0, ViewGroup.LayoutParams.WRAP_CONTENT));

        btn.setId(View.generateViewId());
        //sets button text from array
        btn.setText(buttonText);

        //sets color of button based of pos in list (red for even blue for odd)
        if((contactButtonList.size()%2) == 0) {
            btn.setBackgroundResource(R.drawable.red_button);
        }else{
            btn.setBackgroundResource(R.drawable.blue_button);
        }

        //adds the button to the layout
        layout.addView(btn,contactButtonList.size());

        //sets the constraint set to match the current layout.... i think?, this needs to be done after adding the view
        set.clone(layout);

        //sets button width to match constraint
        set.constrainDefaultWidth(btn.getId(), ConstraintSet.MATCH_CONSTRAINT_SPREAD);

        //connects button to left vert constraint
        set.connect(btn.getId(), ConstraintSet.LEFT, R.id.guideline19, ConstraintSet.RIGHT, 8);
        //connects button to right ver constraint
        set.connect(btn.getId(), ConstraintSet.RIGHT, R.id.guideline20, ConstraintSet.RIGHT, 8);

        //if first button attaches to horz constraint else attaches to last button
        if(contactButtonList.isEmpty()){
            set.connect(btn.getId(), ConstraintSet.TOP, R.id.guideline18, ConstraintSet.BOTTOM, 8);
        }else{
            set.connect(btn.getId(), ConstraintSet.TOP, contactButtonList.get(contactButtonList.size() - 1).getId(), ConstraintSet.BOTTOM);
        }

        //adds button to list
        contactButtonList.add(btn);
        //adds id to list
        contactIdList.add(contactsArray[i][1]);

        //apply set to layout
        set.applyTo(layout);
    }


}