For Android: How to setup checked radio button in RadioGroup programmatically

注意順序,是先加入RadioGroup再設定其checked Id.
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 LinearLayout.LayoutParams param4RdoGrp=new LinearLayout.LayoutParams(
 ViewGroup.LayoutParams.WRAP_CONTENT,
 ViewGroup.LayoutParams.WRAP_CONTENT
 );
 param4RdoGrp.setMargins(16, 0, 0, 0);
 radioGroup=new RadioGroup(activityContex);
 radioGroup.setOrientation(RadioGroup.HORIZONTAL);
 radioGroup.setLayoutParams(param4RdoGrp);
 currentView.addView(radioGroup);
      int checkId=-1;
 for(int i=0;i<options.length;i++){
          RadioButton rdoBtn=new RadioButton(activityContex);
          rdoBtn.setText(options[i]);
          radioGroup.addView(rdoBtn);  <--先加入有了id再決定怎麼做
          if(options[i].equals(selectedOption)){
        // rdoBtn.setChecked(true);   <--這樣不行,會把radio button 卡住!!
         checkId=rdoBtn.getId();
          }
         
 }
 if(checkId!=-1){
 radioGroup.check(checkId);   <--這時才能設定check!!
 }

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