如何在android中的spinner数组适配器中实现添加项目

Question

我有一个EditText,一个按钮和一个微调器.单击该按钮时,微调器将添加一个新项目,其中包含您在EditText中输入的名称.但这是问题,我的adapter.add()方法似乎不起作用...这是我的代码:

  bt1 = (Button)this.findViewById(R.id.AddBtn);
            et = (EditText)this.findViewById(R.id.newSpinnerItemText);  
            spinner = (Spinner)this.findViewById(R.id.dynamicSpinner);

            adapter = ArrayAdapter.createFromResource(
                    this, R.array.simple_from_length, android.R.layout.simple_spinner_item);

            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

            spinner.setAdapter(adapter);

            bt1.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    String temp = et.getText().toString();

                    adapter.add(temp);
                //    adapter.notifyDataSetChanged();
                    spinner.setAdapter(adapter);

                }
            });

这个文件的错误:

02-27 18:01:17.728: ERROR/AndroidRuntime(1982): java.lang.UnsupportedOperationException
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at java.util.AbstractList.add(AbstractList.java:410)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at java.util.AbstractList.add(AbstractList.java:432)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.widget.ArrayAdapter.add(ArrayAdapter.java:178)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at org.example.SpinnerKiran.SpinnerKiran$1.onClick(SpinnerKiran.java:56)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.View.performClick(View.java:2179)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.View.onTouchEvent(View.java:3828)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.widget.TextView.onTouchEvent(TextView.java:6291)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.View.dispatchTouchEvent(View.java:3368)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1707)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1197)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.app.Activity.dispatchTouchEvent(Activity.java:1993)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1691)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1525)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.os.Handler.dispatchMessage(Handler.java:99)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.os.Looper.loop(Looper.java:123)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at android.app.ActivityThread.main(ActivityThread.java:3948)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at java.lang.reflect.Method.invokeNative(Native Method)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at java.lang.reflect.Method.invoke(Method.java:521)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
02-27 18:01:17.728: ERROR/AndroidRuntime(1982):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

ArrayAdapter已基于List,因此您无需仅使用List来创建自定义适配器.但是,它使用它创建的List或数组.它不会将元素复制到新列表中.如果给它一个固定长度的数组,则无法添加或删除成员.

创建一个List以传递给构造函数.请注意,从Arrays.asList()创建的List将不起作用,因为它只是原始数组的表示.

        spinner = (Spinner)this.findViewById(R.id.dynamicSpinner);
        CharSequence[] itemArray = 
                getResources().getTextArray(R.array.simple_from_length);
        List<CharSequence> itemList = 
                new ArrayList<CharSequence>(Arrays.asList(itemArray));

        adapter = new ArrayAdapter(this, 
                android.R.layout.simple_spinner_item,
                itemList);

        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        spinner.setAdapter(adapter);

您还可以使用List <String>和getResources.getStringArray(),或任何方便的方法.