java单选按钮设置默认值,如何在radiogroup中将单选按钮设置为默认值？

这是RadioGroup的一个错误

RadioButton radioBtn2 = new RadioButton(context);

radioBtn2没有viewId，而generateViewId在onChildViewAdded()

public void onChildViewAdded(View parent, View child) {

if (parent == RadioGroup.this && child instanceof RadioButton) {

int id = child.getId();

// generates an id if it's missing

if (id == View.NO_ID) {

id = View.generateViewId();

child.setId(id);

}

((RadioButton) child).setOnCheckedChangeWidgetListener(

mChildOnCheckedChangeListener);

}

if (mOnHierarchyChangeListener != null) {

mOnHierarchyChangeListener.onChildViewAdded(parent, child);

}

}

所以，首先是radioGroup.addView(radioBtn2)，然后是radioBtn2.setChecked(true);

像这样：

RadioGroup radioGroup = new RadioGroup(context);

RadioButton radioBtn1 = new RadioButton(context);

RadioButton radioBtn2 = new RadioButton(context);

RadioButton radioBtn3 = new RadioButton(context);

radioBtn1.setText("Less");

radioBtn2.setText("Normal");

radioBtn3.setText("More");

radioGroup.addView(radioBtn1);

radioGroup.addView(radioBtn2);

radioGroup.addView(radioBtn3);

radioBtn2.setChecked(true);