在 OnCreate() 中创建对象 RadioGroup 时,稍后在另一个函数中调用此对象时,它会显示错误“无法解析此符号”
这是java代码
MainActivity.java
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RadioGroup group1 = (RadioGroup)findViewById(R.id.que1_rG);
RadioGroup group2 = (RadioGroup)findViewById(R.id.que2rG);
RadioGroup group3 = (RadioGroup)findViewById(R.id.que3rG);
RadioGroup group4 = (RadioGroup)findViewById(R.id.que4rG);
RadioGroup group5 = (RadioGroup)findViewById(R.id.que5rG);
RadioGroup group6 = (RadioGroup)findViewById(R.id.que6rG);
RadioGroup group7 = (RadioGroup)findViewById(R.id.que7rG);
RadioGroup group8 = (RadioGroup)findViewById(R.id.que8rG);
RadioGroup group9 = (RadioGroup)findViewById(R.id.que9rG);
RadioGroup group10 = (RadioGroup)findViewById(R.id.que10rG);
}
public void submitButton(View view)
{
int checkedRadio1= group1.getCheckedRadioButtonId();
Toast.makeText(this,"Score is : " + score,Toast.LENGTH_SHORT);
Log.v("MainActivity","Score is " + score);
score = 0;
}
最佳答案
您收到 cannot resolve symbol 的原因是您尚未在类级别声明您的 RadioGroup group1
。由于您已在 onCreate
中声明和分配,因此其范围仅限于 onCreate()
。要在其他方法中访问,请将其作为类成员。
声明RadioGroup group1
为类成员如下:
public class MainAcivity extends Activity{
private RadioGroup group1;
//Declare other RadioGroup group2,group3...group 10. if you intend
//to access them outside of onCreate()
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
group1 = (RadioGroup)findViewById(R.id.que1_rG);
...
}
public void submitButton(View view) {
int checkedRadio1= group1.getCheckedRadioButtonId();
Toast.makeText(this,"Score is : " + score,Toast.LENGTH_SHORT).show();
Log.v("MainActivity","Score is " + score);
score = 0;
}
}
注意:
同样的事情适用于您希望在 onCreate()
之外访问的任何其他 RadioGroup
。
在尝试显示 Toast
时,您还缺少对 show()
方法的调用。如果不调用 show()
,将不会显示 Toast 消息。
代替
Toast.makeText(this,"Score is : "+ score,Toast.LENGTH_SHORT)
使用
Toast.makeText(this,"Score is : "+ score,Toast.LENGTH_SHORT).show()
关于java - 无法为对象解析此符号,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51115398/