该文章主要改动于CSDN某大神的一篇文章,本人认为这篇文章的面向对象非常透彻,以下分享例如以下可学习的几点:
Android应用经典主界面框架之中的一个:仿QQ (使用Fragment, 附源代码)
1.通过&符号实现计算优化:(后来通过问同事,说是计算机通过位运算 效率比平时的switch效率高,并解说了该算法的原理。)
- public class Constant {
- public static final int SIGN_FRAGMENT_MESSAGE=0x01 <<1;
- public static final int SIGN_FRAGMENT_CONTACTS=0x01 <<2;
- public static final int SIGN_FRAGMENT_NEWS=0x01 <<3;
- public static final int SIGN_FRAGMENT_SETTENGS=0x01 <<4;
- }
- @Override
- public void onClickCallBack(int itemID) {
- String tag = "";
- if ((itemID & Constant.SIGN_FRAGMENT_MESSAGE) != 0) {
- tag = Constant.STR_FRAGMENT_MESSAGE;
- } else if ((itemID & Constant.SIGN_FRAGMENT_CONTACTS) != 0) {
- tag = Constant.STR_FRAGMENT_CONTACTS;
- } else if ((itemID & Constant.SIGN_FRAGMENT_NEWS) != 0) {
- tag = Constant.STR_FRAGMENT_NEWS;
- } else if ((itemID & Constant.SIGN_FRAGMENT_SETTENGS) != 0) {
- tag = Constant.STR_FRAGMENT_SETTINGS;
- }
- mHeaderPanelLayout.setText(tag);
- setTabSection(tag);
- }
2.通过onLayout对底部栏中间的button进行“动态”调整
- @Override
- protected void onLayout(boolean changed, int l, int t, int r, int b) {
- super.onLayout(changed, l, t, r, b);
- layoutItem(l, t, r, b);
- }
- private void layoutItem(int left, int top, int right, int bottom) {
- int allChildWidth=0;
- int num=getChildCount();
- for (int i = 0; i < num; i++) {
- allChildWidth+=getChildAt(i).getWidth();
- }
- int absoluteWidth=right-left-getPaddingLeft()-getPaddingRight();
- int blankWidth=(absoluteWidth-allChildWidth)/(num-1);
- //设置第2 3个button的间距
- LayoutParams params1=(LayoutParams) mContactsBtn.getLayoutParams();
- params1.leftMargin=blankWidth;
- mContactsBtn.setLayoutParams(params1);
- LayoutParams params2=(LayoutParams) mNewsBtn.getLayoutParams();
- params2.leftMargin=blankWidth;
- mNewsBtn.setLayoutParams(params2);
- }
3.两种实例化布局的应用:
1)通过layoutInflater.
- public ImageText(Context context, AttributeSet attrs) {
- super(context, attrs);
- LayoutInflater.from(context).inflate(R.layout.image_text_layout, this,true);
- mImageView=(ImageView) findViewById(R.id.iv_imgae_text);
- mTextiew=(TextView) findViewById(R.id.tv_imgae_text);
- }
2)通过onFinishInflater()
- <?xml version="1.0" encoding="utf-8"?>
- <org.lean.ui.BottomPanelLayout
- xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:background="#FFF3F3F3"
- android:paddingLeft="20dp"
- android:paddingRight="20dp"
- android:layout_alignParentBottom="true" >
- <org.lean.ui.ImageText
- android:id="@+id/message_btn"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:layout_alignParentLeft="true" />
- <org.lean.ui.ImageText
- android:id="@+id/contacts_btn"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:layout_toRightOf="@id/message_btn" />
- <org.lean.ui.ImageText
- android:id="@+id/news_btn"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:layout_toRightOf="@id/contacts_btn" />
- <org.lean.ui.ImageText
- android:id="@+id/settings_btn"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:layout_alignParentRight="true" />
- </org.lean.ui.BottomPanelLayout>
- @Override
- protected void onFinishInflate() {
- super.onFinishInflate();
- mMessageBtn=(ImageText) findViewById(R.id.message_btn);
- mContactsBtn=(ImageText) findViewById(R.id.contacts_btn);
- mNewsBtn=(ImageText) findViewById(R.id.news_btn);
- mSettingsBtn=(ImageText) findViewById(R.id.settings_btn);
- initClickEvent();
- }
4.代理实现数据传递(IOS中最经常使用的一种设计模式)
- public class BottomPanelLayout extends RelativeLayout implements OnClickListener{
- private BottomPanelCallBackProtocal mCallBackProtocal;
- //代理协议
- public void setCallBackProtocal(BottomPanelCallBackProtocal callBackProtocal) {
- this.mCallBackProtocal = callBackProtocal;
- }
- public interface BottomPanelCallBackProtocal{
- public void onClickCallBack(int itemID);
- }
- /**
- * 1.改动本身样式
- * 2.对外声明事件
- */
- @Override
- public void onClick(View v) {
- initBottomPanel();
- int index=-1;
- switch (v.getId()) {
- case R.id.message_btn:
- index=Constant.SIGN_FRAGMENT_MESSAGE;
- mMessageBtn.setChecked(index);
- break;
- case R.id.contacts_btn:
- index=Constant.SIGN_FRAGMENT_CONTACTS;
- mContactsBtn.setChecked(index);
- break;
- case R.id.news_btn:
- index=Constant.SIGN_FRAGMENT_NEWS;
- mNewsBtn.setChecked(index);
- break;
- case R.id.settings_btn:
- index=Constant.SIGN_FRAGMENT_SETTENGS;
- mSettingsBtn.setChecked(index);
- break;
- default:
- break;
- }
- if (mCallBackProtocal!=null) {
- mCallBackProtocal.onClickCallBack(index);
- }
- }
- }
- public class MainActivity extends Activity implements
- BottomPanelCallBackProtocal {
- @Override
- public void onClickCallBack(int itemID) {
- String tag = "";
- if ((itemID & Constant.SIGN_FRAGMENT_MESSAGE) != 0) {
- tag = Constant.STR_FRAGMENT_MESSAGE;
- } else if ((itemID & Constant.SIGN_FRAGMENT_CONTACTS) != 0) {
- tag = Constant.STR_FRAGMENT_CONTACTS;
- } else if ((itemID & Constant.SIGN_FRAGMENT_NEWS) != 0) {
- tag = Constant.STR_FRAGMENT_NEWS;
- } else if ((itemID & Constant.SIGN_FRAGMENT_SETTENGS) != 0) {
- tag = Constant.STR_FRAGMENT_SETTINGS;
- }
- mHeaderPanelLayout.setText(tag);
- setTabSection(tag);
- }
- }
5.改动原来Fragment跳转的代码(之前方法ensureTransaction()是在粘贴或者消除的时候都要推断,但作为一个事务,仅仅须要保证事物仅仅有一个開始就可以,而不须要每次都调用)
- private void setTabSection(String tag) {
- if (TextUtils.equals(tag, currFagTag)) {
- return;
- }
- ensureTransaction();
- if (currFagTag != null && !currFagTag.equals("")) {
- detachFragment(getFragment(currFagTag));
- }
- attachFragment(R.id.fragment_panel, getFragment(tag), tag);
- commitTransaction();
- }
- private void ensureTransaction() {
- if (mFragmentTransaction == null) {
- mFragmentTransaction = mFragmentManager.beginTransaction();
- mFragmentTransaction
- .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
- }
- }
6.Fragment对Fragment进行跳转并传值的改进。(这里试验从MessageFragment 点击textview跳转到 ContactFragment );
1>在MessageFragment 中
- @Override
- public void onActivityCreated(Bundle savedInstanceState) {
- super.onActivityCreated(savedInstanceState);
- getActivity().findViewById(R.id.msg_tv).setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- ((MainActivity)getActivity()).setTabSection(Constant.STR_FRAGMENT_CONTACTS);
- }
- });
- }
2>在ContactFragment 中声明数据代理
- //声明一个变量,该变量存储该Fragment所须要的一切參数 当刷新View时手动调用其更新数据
- private ContactFragmentCallBack mContactFragmentCallBack;
- //声明该接口
- public interface ContactFragmentCallBack{
- //说明该Fragment更新时须要一个String对象
- public String getContentStr();
- }
3>MessageFragment 实现该代理
- public class MessageFragment extends BaseFragment implements ContactFragmentCallBack{
- @Override
- public String getContentStr() {
- return "abc";
- }
- }
4>在ContactFragment 中回调
- @Override
- public void onResume() {
- super.onResume();
- MainActivity.currFagTag=Constant.STR_FRAGMENT_CONTACTS;
- //通过取出 存储于上个Fragment中的数据
- Fragment f=((MainActivity)getActivity()).getFragment(Constant.STR_FRAGMENT_MESSAGE);
- if (f!=null&&f instanceof ContactFragmentCallBack) {
- mContactFragmentCallBack=(ContactFragmentCallBack)f;
- TextView textView=(TextView) ((MainActivity)getActivity()).findViewById(R.id.contact_tv);
- textView.setText(mContactFragmentCallBack.getContentStr());
- }
- }