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());
}
}