android-改进<<仿QQ>>框架源代码

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());
		}
	}

改动后的项目源代码