android之Tabhost深入讲解一
大家都知道Tabhost中Tabwidget的布局是图标在上，文字在下的垂直布局。比如通讯录的布局。
这种布局在手机上的竖屏上用得最多，但在横屏则显得水平分布得不够紧凑。如何实现自定义的布局呢？
1：首先理解Tabhost的布局：
<?xml version="1.0" encoding="utf-8"?><TabHost xmlns:android="http://schemas.android.com/apk/res/android"android:id="@android:id/tabhost" android:layout_width="fill_parent"android:layout_height="fill_parent"><LinearLayout android:orientation="vertical"android:layout_width="fill_parent" android:layout_height="fill_parent"><TabWidget android:id="@android:id/tabs" android:layout_width="fill_parent" android:layout_height="wrap_content" /><FrameLayout android:id="@android:id/tabcontent"android:layout_width="fill_parent" android:layout_height="0dip"android:layout_weight="1"></FrameLayout></LinearLayout></TabHost>
?TabHost里面包含了一个<LinearLayout>,然后LinearLayout里面有一个TabWidget 这个存放每个“切换卡”，FrameLayout里面存放每个切换卡下面的内容，
TabWidget 理解： ?
1. TabWidget 为 horizontal 的 LinearLayout ?
2. 且 其包含的标签又是一个RelativeLayout ?
3. 每个标签RelativeLayout 里面包含2个View: TextView ImageView?
有了这个理解，可以估计得到
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent" ><RelativeLayout android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content"> <ImageView /> <TextView /></RelativeLayout><RelativeLayout android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content"> <ImageView /> <TextView /></RelativeLayout>..........多个RelativeLayout </LinearLayout>
?有了这个布局，就可以自定义自己的布局了，以图片在左，文字在右为例。
package com.android.customtabhost;import android.app.TabActivity;import android.content.Intent;import android.os.Bundle;import android.view.Gravity;import android.view.View;import android.view.Window;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.RelativeLayout;import android.widget.TabHost;import android.widget.TabWidget;import android.widget.TextView;public class CustomTabHost extends TabActivity { private TabHost mTabHost; private static final String TAB_SETTING_TAG_0 = "tab_setting0"; private static final String TAB_SETTING_TAG_1 = "tab_setting1"; private static final String TAB_SETTING_TAG_2 = "tab_setting2"; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); //setContentView(R.layout.main); mTabHost = getTabHost(); // Setup the tabs setupSettingTab(TAB_SETTING_TAG_0, 0); setupSettingTab(TAB_SETTING_TAG_1, 1); setupSettingTab(TAB_SETTING_TAG_2, 2); } private void setupSettingTab(String tag, int num) { // TODO Auto-generated method stub // Force the class since overriding tab entries doesn't work Intent intent = new Intent(); intent.setClass(this, SettingActivity.class); String name = getResources().getString(R.string.setting); mTabHost.addTab(mTabHost.newTabSpec(tag).setIndicator("") .setContent(intent)); addToTabHost(name, R.drawable.setting_background, num); } private void addToTabHost(String name, int image, int number) { // TODO Auto-generated method stub LinearLayout ll = (LinearLayout) mTabHost.getChildAt(0); TabWidget tw = (TabWidget) ll.getChildAt(0); RelativeLayout rl = (RelativeLayout) tw.getChildAt(number); rl.addView(composeLayout(name, image), new LinearLayout.LayoutParams( LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.FILL_PARENT)); } private View composeLayout(String name, int image) { LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.HORIZONTAL); ImageView iv = new ImageView(this); iv.setImageResource(image); layout.addView(iv, new LinearLayout.LayoutParams( LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.FILL_PARENT)); TextView tv = new TextView(this); tv.setGravity(Gravity.CENTER); tv.setSingleLine(true); tv.setPadding(10, 0, 0, 0); tv.setTextSize(18); tv.setText(name); layout.addView(tv, new LinearLayout.LayoutParams( LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.FILL_PARENT)); return layout; }}?