2G03-view-radio-group

注意两点

1.通过android:checkedButton="@+id/lunch"而不是item中的 android:checked="true"设置的某人被选中状态

  <RadioGroup        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="vertical"        android:checkedButton="@+id/lunch"        android:id="@+id/menu">

2.mRadioGroup.clearCheck();清楚所有的选中状态

/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.example.android.apis.view;import com.example.android.apis.R;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.TextView;import android.widget.RadioGroup;import android.widget.Button;import android.widget.RadioButton;import android.widget.LinearLayout;public class RadioGroup1 extends Activity implements RadioGroup.OnCheckedChangeListener,        View.OnClickListener {    private TextView mChoice;    private RadioGroup mRadioGroup;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.radio_group_1);        mRadioGroup = (RadioGroup) findViewById(R.id.menu);        // test adding a radio button programmatically        RadioButton newRadioButton = new RadioButton(this);        newRadioButton.setText(R.string.radio_group_snack);        newRadioButton.setId(R.id.snack);        LinearLayout.LayoutParams layoutParams = new RadioGroup.LayoutParams(                RadioGroup.LayoutParams.WRAP_CONTENT,                RadioGroup.LayoutParams.WRAP_CONTENT);        mRadioGroup.addView(newRadioButton, 0, layoutParams);        // test listening to checked change events        String selection = getString(R.string.radio_group_selection);        mRadioGroup.setOnCheckedChangeListener(this);        mChoice = (TextView) findViewById(R.id.choice);        mChoice.setText(selection + mRadioGroup.getCheckedRadioButtonId());        // test clearing the selection        Button clearButton = (Button) findViewById(R.id.clear);        clearButton.setOnClickListener(this);    }    public void onCheckedChanged(RadioGroup group, int checkedId) {        String selection = getString(R.string.radio_group_selection);        String none = getString(R.string.radio_group_none);        mChoice.setText(selection +                (checkedId == View.NO_ID ? none : checkedId));    }    public void onClick(View v) {        mRadioGroup.clearCheck();    }}

radio_group_1,xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    <RadioGroup        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="vertical"        android:checkedButton="@+id/lunch"        android:id="@+id/menu">        <RadioButton            android:text="@string/radio_group_1_breakfast"            android:id="@+id/breakfast"            />        <RadioButton            android:text="@string/radio_group_1_lunch"            android:id="@id/lunch" />        <RadioButton            android:text="@string/radio_group_1_dinner"            android:id="@+id/dinner" />        <RadioButton            android:text="@string/radio_group_1_all"            android:id="@+id/all" />        <TextView            android:text="@string/radio_group_1_selection"            android:id="@+id/choice" />    </RadioGroup>    <Button        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="@string/radio_group_1_clear"        android:id="@+id/clear" /></LinearLayout>