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android - Android中的空对象引用

问题描述

我正在尝试在广播组工作。我有一个ok按钮，单击该按钮时会从四个膨胀的单选按钮组中选择一项。我的问题是，当用户没有从其中一个组中选择一个选项时，我有一个空指针异常。

这是我的选择代码

private void getSelectedValuesAdults()
{
    rl=(RelativeLayout)findViewById(R.id.activity_selections);

    int id1 = ((RadioGroup)findViewById(R.id.KSradioGrp)).getCheckedRadioButtonId();
    int id2 = ((RadioGroup)findViewById(R.id.KTradioGrp)).getCheckedRadioButtonId();
    int id3 = ((RadioGroup)findViewById(R.id.KDradioGrp)).getCheckedRadioButtonId();
    int id4 = ((RadioGroup)findViewById(R.id.KSoradioGrp)).getCheckedRadioButtonId();

    stringChoice[0]= ((RadioButton)findViewById(id1)).getText().toString().contains(generalKid[0].getName())==true?generalKid[0].getName():generalKid[1].getName();      
    stringChoice[1]= ((RadioButton)findViewById(id2)).getText().toString().contains(generalKid[2].getName())==true?generalKid[2].getName():generalKid[3].getName();
    stringChoice[2]= ((RadioButton)findViewById(id3)).getText().toString().contains(generalKid[4].getName())==true?generalKid[4].getName():generalKid[5].getName();
    stringChoice[3]= ((RadioButton)findViewById(id4)).getText().toString().contains(generalKid[6].getName())==true?generalKid[6].getName():generalKid[7].getName();

    genCost[0]= ((RadioButton)findViewById(id1)).getText().toString().contains(generalKid[0].getName())==true?generalKid[0].getCost()+5:generalKid[1].getCost()+5;
    genCost[0]= ((RadioButton)findViewById(id2)).getText().toString().contains(generalKid[2].getName())==true?generalKid[2].getCost()+5:generalKid[3].getCost()+5;
    genCost[0]= ((RadioButton)findViewById(id3)).getText().toString().contains(generalKid[4].getName())==true?generalKid[4].getCost()+5:generalKid[5].getCost()+5;
    genCost[0]= ((RadioButton)findViewById(id4)).getText().toString().contains(generalKid[6].getName())==true?generalKid[6].getCost()+5:generalKid[7].getCost()+5;

}

Ok 按钮跳转到上面的方法。我在分配到whereif(id1==-1||id2==-1||id3==-1||id4==-1) callDialogMessage()之前使用了一条消息，让您知道您尚未从广播组中选择，但我的应用程序仍然崩溃。我能做些什么？任何帮助将不胜感激stringChoice[0]callDialogMessage()

标签： androidandroid-studioandroid-layoutandroid-radiobuttonandroid-radiogroup

解决方案

On click of OK button get selected radio button Id using radio group .You can refer the below code.

     int selectedId =radioButtonGroup.getCheckedRadioButtonId();;

        // find the radiobutton by returned id
     RadioButton radioButton = FindViewById<RadioButton>(selectedId);

     if(radioButton !=null)
      {
        //do things here
      }

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