今天做一個單選框，效果如下：
使用原始的RadioGroup可以實現布局，但因為把6個單選分為兩個LinearLayout，導致無法互斥，Google官方的做法是寫兩個RadioGroup，但是要動態監聽，感覺好麻煩，最理想的辦法是自定義一個RadioGroup，一勞永逸。
原文地址：https://github.com/pheng/android_radiogroup_MutilRadioGroup
一個類足以，的確很牛逼，原理應該是拿所有嵌套布局里的RadioButton，然后動態重新組了一遍，既保證布局，又實現互斥。
import android.annotation.SuppressLint; import android.content.Context; import android.content.res.TypedArray; import android.os.Build; import android.util.AttributeSet; import android.view.View; import android.view.ViewGroup; import android.view.accessibility.AccessibilityEvent; import android.view.accessibility.AccessibilityNodeInfo; import android.widget.CompoundButton; import android.widget.LinearLayout; import android.widget.RadioButton; import java.util.ArrayList; import java.util.List; public class MultiLineRadioGroup extends LinearLayout { // holds the checked id; the selection is empty by default
private int mCheckedId = -1; // tracks children radio buttons checked state
private CompoundButton.OnCheckedChangeListener mChildOnCheckedChangeListener; // when true, mOnCheckedChangeListener discards events
private boolean mProtectFromCheckedChange = false; private OnCheckedChangeListener mOnCheckedChangeListener; private PassThroughHierarchyChangeListener mPassThroughListener; /** * {@inheritDoc} */
public MultiLineRadioGroup(Context context) { super(context); setOrientation(VERTICAL); init(); } /** * {@inheritDoc} */
public MultiLineRadioGroup(Context context, AttributeSet attrs) { super(context, attrs); init(); } private void init() { mChildOnCheckedChangeListener = new CheckedStateTracker(); mPassThroughListener = new PassThroughHierarchyChangeListener(); super.setOnHierarchyChangeListener(mPassThroughListener); } /** * {@inheritDoc} */ @Override public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) { // the user listener is delegated to our pass-through listener
mPassThroughListener.mOnHierarchyChangeListener = listener; } /** * set the default checked radio button, without notification the listeners */
public void setCheckWithoutNotif(int id) { if (id != -1 && (id == mCheckedId)) { return; } mProtectFromCheckedChange = true; if (mCheckedId != -1) { setCheckedStateForView(mCheckedId, false); } if (id != -1) { setCheckedStateForView(id, true); } mCheckedId = id; mProtectFromCheckedChange = false; } @Override public void addView(View child, int index, ViewGroup.LayoutParams params) { List<RadioButton> btns = getAllRadioButton(child); if (btns != null && btns.size() > 0) { for (RadioButton button : btns) { if (button.isChecked()) { mProtectFromCheckedChange = true; if (mCheckedId != -1) { setCheckedStateForView(mCheckedId, false); } mProtectFromCheckedChange = false; setCheckedId(button.getId()); } } } super.addView(child, index, params); } /** * get all radio buttons which are in the view * * @param child */
private List<RadioButton> getAllRadioButton(View child) { List<RadioButton> btns = new ArrayList<RadioButton>(); if (child instanceof RadioButton) { btns.add((RadioButton) child); } else if (child instanceof ViewGroup) { int counts = ((ViewGroup) child).getChildCount(); for (int i = 0; i < counts; i++) { btns.addAll(getAllRadioButton(((ViewGroup) child).getChildAt(i))); } } return btns; } /** * <p>Sets the selection to the radio button whose identifier is passed in * parameter. Using -1 as the selection identifier clears the selection; * such an operation is equivalent to invoking {@link #clearCheck()}.</p> * * @param id the unique id of the radio button to select in this group * @see #getCheckedRadioButtonId() * @see #clearCheck() */
public void check(int id) { // don't even bother
if (id != -1 && (id == mCheckedId)) { return; } if (mCheckedId != -1) { setCheckedStateForView(mCheckedId, false); } if (id != -1) { setCheckedStateForView(id, true); } setCheckedId(id); } private void setCheckedId(int id) { mCheckedId = id; if (mOnCheckedChangeListener != null) { mOnCheckedChangeListener.onCheckedChanged(this, mCheckedId); } } private void setCheckedStateForView(int viewId, boolean checked) { View checkedView = findViewById(viewId); if (checkedView != null && checkedView instanceof RadioButton) { ((RadioButton) checkedView).setChecked(checked); } } /** * <p>Returns the identifier of the selected radio button in this group. * Upon empty selection, the returned value is -1.</p> * * @return the unique id of the selected radio button in this group * @attr ref android.R.styleable#MyRadioGroup_checkedButton * @see #check(int) * @see #clearCheck() */
public int getCheckedRadioButtonId() { return mCheckedId; } /** * <p>Clears the selection. When the selection is cleared, no radio button * in this group is selected and {@link #getCheckedRadioButtonId()} returns * null.</p> * * @see #check(int) * @see #getCheckedRadioButtonId() */
public void clearCheck() { check(-1); } /** * <p>Register a callback to be invoked when the checked radio button * changes in this group.</p> * * @param listener the callback to call on checked state change */
public void setOnCheckedChangeListener(OnCheckedChangeListener listener) { mOnCheckedChangeListener = listener; } /** * {@inheritDoc} */ @Override public LayoutParams generateLayoutParams(AttributeSet attrs) { return new MultiLineRadioGroup.LayoutParams(getContext(), attrs); } /** * {@inheritDoc} */ @Override protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { return p instanceof MultiLineRadioGroup.LayoutParams; } @Override protected LinearLayout.LayoutParams generateDefaultLayoutParams() { return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); } @Override public void onInitializeAccessibilityEvent(AccessibilityEvent event) { super.onInitializeAccessibilityEvent(event); event.setClassName(MultiLineRadioGroup.class.getName()); } @Override public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) { super.onInitializeAccessibilityNodeInfo(info); info.setClassName(MultiLineRadioGroup.class.getName()); } /** * <p>This set of layout parameters defaults the width and the height of * the children to {@link #WRAP_CONTENT} when they are not specified in the * XML file. Otherwise, this class ussed the value read from the XML file.</p> * <p/> * <p>See * for a list of all child view attributes that this class supports.</p> */
public static class LayoutParams extends LinearLayout.LayoutParams { /** * {@inheritDoc} */
public LayoutParams(Context c, AttributeSet attrs) { super(c, attrs); } /** * {@inheritDoc} */
public LayoutParams(int w, int h) { super(w, h); } /** * {@inheritDoc} */
public LayoutParams(int w, int h, float initWeight) { super(w, h, initWeight); } /** * {@inheritDoc} */
public LayoutParams(ViewGroup.LayoutParams p) { super(p); } /** * {@inheritDoc} */
public LayoutParams(MarginLayoutParams source) { super(source); } /** * <p>Fixes the child's width to * {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT} and the child's * height to {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT} * when not specified in the XML file.</p> * * @param a the styled attributes set * @param widthAttr the width attribute to fetch * @param heightAttr the height attribute to fetch */ @Override protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr) { if (a.hasValue(widthAttr)) { width = a.getLayoutDimension(widthAttr, "layout_width"); } else { width = WRAP_CONTENT; } if (a.hasValue(heightAttr)) { height = a.getLayoutDimension(heightAttr, "layout_height"); } else { height = WRAP_CONTENT; } } } /** * <p>Interface definition for a callback to be invoked when the checked * radio button changed in this group.</p> */
public interface OnCheckedChangeListener { /** * <p>Called when the checked radio button has changed. When the * selection is cleared, checkedId is -1.</p> * * @param group the group in which the checked radio button has changed * @param checkedId the unique identifier of the newly checked radio button */
public void onCheckedChanged(MultiLineRadioGroup group, int checkedId); } private class CheckedStateTracker implements CompoundButton.OnCheckedChangeListener { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // prevents from infinite recursion
if (mProtectFromCheckedChange) { return; } mProtectFromCheckedChange = true; if (mCheckedId != -1) { setCheckedStateForView(mCheckedId, false); } mProtectFromCheckedChange = false; int id = buttonView.getId(); setCheckedId(id); } } /** * <p>A pass-through listener acts upon the events and dispatches them * to another listener. This allows the table layout to set its own internal * hierarchy change listener without preventing the user to setup his.</p> */
private class PassThroughHierarchyChangeListener implements ViewGroup.OnHierarchyChangeListener { private ViewGroup.OnHierarchyChangeListener mOnHierarchyChangeListener; /** * {@inheritDoc} */ @SuppressLint("NewApi") public void onChildViewAdded(View parent, View child) { if (parent == MultiLineRadioGroup.this) { List<RadioButton> btns = getAllRadioButton(child); if (btns != null && btns.size() > 0) { for (RadioButton btn : btns) { int id = btn.getId(); // generates an id if it's missing
if (id == View.NO_ID && Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) { id = View.generateViewId(); btn.setId(id); } btn.setOnCheckedChangeListener( mChildOnCheckedChangeListener); } } } if (mOnHierarchyChangeListener != null) { mOnHierarchyChangeListener.onChildViewAdded(parent, child); } } /** * {@inheritDoc} */
public void onChildViewRemoved(View parent, View child) { if (parent == MultiLineRadioGroup.this) { List<RadioButton> btns = getAllRadioButton(child); if (btns != null && btns.size() > 0) { for (RadioButton btn : btns) { btn.setOnCheckedChangeListener(null); } } } if (mOnHierarchyChangeListener != null) { mOnHierarchyChangeListener.onChildViewRemoved(parent, child); } } } }
然后調用即可：
<com.xuehu365.xuehu.utils.MultiLineRadioGroup android:id="@+id/type" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp" android:background="@color/white" android:orientation="vertical" android:padding="10dp">
<LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal">
<RadioButton android:id="@+id/experienceProblem" style="@style/counsel_radio_button" android:text="體驗問題" />
<RadioButton android:id="@+id/userAdvice" style="@style/counsel_radio_button" android:text="功能建議" />
<RadioButton android:id="@+id/contentSuggest" style="@style/counsel_radio_button" android:text="內容意見" />
</LinearLayout>
<LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal">
<RadioButton android:id="@+id/courseBuy" style="@style/counsel_radio_button" android:text="課程購買" />
<RadioButton android:id="@+id/webProblem" style="@style/counsel_radio_button" android:text="網絡問題" />
<RadioButton android:id="@+id/other" style="@style/counsel_radio_button" android:text="其它" />
</LinearLayout>
</com.xuehu365.xuehu.utils.MultiLineRadioGroup>