android - 如何在自定义对话框中添加 radiogroup onchecked 监听器

Question

我有一个包含单选按钮的自定义对话框，但是当我添加一个 oncheckedchangelistener 时，我的应用程序崩溃了。可能是什么问题？

提前致谢! :D

这是我的代码:

GridViewAdapter adapter = new GridViewAdapter(alcoholType.this, images,names);
    gridView.setAdapter(adapter);
    gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {

            final Dialog dialog = new Dialog(context);
            dialog.setContentView(R.layout.alcoholdialog);
            dialog.setTitle("ORDER " + names.get(position));

            radioQuantity = (RadioGroup) findViewById(R.id.radioQuantity);
            quantity1 = (RadioButton) findViewById(R.id.quantity1);
            quantity2 = (RadioButton) findViewById(R.id.quantity2);

            radioQuantity.clearCheck();

            radioQuantity.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {

                        @Override
                        public void onCheckedChanged(RadioGroup group, int checkedId) {


                        }

                    });

            dialog.show();
        }
    });

这是错误轨迹:

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.example.gin.ordering, PID: 22005
              java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.RadioGroup.clearCheck()' on a null object reference
                  at com.example.gin.ordering.alcoholType$1.onItemClick(alcoholType.java:90)
                  at android.widget.AdapterView.performItemClick(AdapterView.java:339)
                  at android.widget.AbsListView.performItemClick(AbsListView.java:1549)
                  at android.widget.AbsListView$PerformClick.run(AbsListView.java:3723)
                  at android.widget.AbsListView$3.run(AbsListView.java:5707)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:145)
                  at android.app.ActivityThread.main(ActivityThread.java:6918)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at java.lang.reflect.Method.invoke(Method.java:372)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)

Answer 1

您需要使用Dialog 的 引用来获取 View 的:

使用:

radioQuantity = (RadioGroup) dialog.findViewById(R.id.radioQuantity);
quantity1 = (RadioButton) dialog.findViewById(R.id.quantity1);
quantity2 = (RadioButton) dialog.findViewById(R.id.quantity2);

你得到 NullPointerException 因为你的 RadioGroup 没有附加到 View 。

同样对于 CheckedListener 使用:

radioQuantity.setOnCheckedChangeListener(new 
   RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {

            if (checkedId == R.id.quantity1) {
                //Your code
            } else if (checkedId == R.id.quantity2) {
                //Your code
            } 

        }
    });