TabHost 简单用法

package com.google.tabhost;  import android.app.TabActivity; import android.os.Bundle; import android.view.LayoutInflater; import android.widget.TabHost;  public class HelloTabHost extends TabActivity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);  //调用TabActivity的getTabHost()方法获取TabHost对象 TabHost tabHost = getTabHost();  //设置使用TabHost布局 LayoutInflater.from(this).inflate(R.layout.main, tabHost.getTabContentView(),true);  //加入第一个标签页 tabHost.addTab(tabHost.newTabSpec("tab01").setIndicator("已接电话").setContent(R.id.tab01));  //加入第二个标签页,并在其标签上加入一个图片 tabHost.addTab(tabHost.newTabSpec("tab02").setIndicator("未接电话",getResources().getDrawable(R.drawable.icon)).setContent(R.id.tab02));  //加入第三个标签页 tabHost.addTab(tabHost.newTabSpec("tab03").setIndicator("已拨电话").setContent(R.id.tab03));  } }

LayoutInflater作用及使用

作用： 

1、对于一个没有被加载或者想要动态加载的界面, 都须要使用inflate来加载. 

2、对于一个已经加载的Activity, 就能够使用实现了这个Activiyt的的findViewById方法来获得当中的界面元素. 

方法： 

   Android里面想要创建一个画面的时候, 初学一般都是新建一个类, 继承Activity基类, 然后在onCreate里面使用setContentView方法来加载一个在xml里定义好的界面. 

   事实上在Activity里面就使用了LayoutInflater来加载界面, 通过getSystemService(Context.LAYOUT_INFLATER_SERVICE)方法能够获得一个 LayoutInflater, 也能够通过LayoutInflater inflater = getLayoutInflater(); 来获得.然后使用inflate方法来加载layout的xml, 

以下是一个简单的样例:

首先我们要知道,什么是已经被加载的layout,什么是还没有加载的.我们启动一个应用,与入口Activity相关的layout{常见的是main.xml}就是被加载的,即在Oncreate()中的.而其它的layout是没有被加载的.就要动态加载了或通过还有一个activity.

在实际开发种LayoutInflater这个类还是很实用的,它的作用类似于 findViewById(),

不同点是LayoutInflater是用来找layout下xml布局文件，而且实例化！而findViewById()是找详细xml下的详细 widget控件.

为了让大家easy理解我[转]做了一个简单的Demo,主布局main.xml里有一个TextView和一个Button，当点击Button，出现 Dialog,而这个Dialog的布局方式是我们在layout文件夹下定义的custom_dialog.xml文件(里面左右分布，左边 ImageView,右边TextView)。

​
​

代码例如以下:

package com.bivin;

import android.app.Activity;

import android.app.AlertDialog;

import android.content.Context;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.ImageView;

import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener {

private Button button;

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

button = (Button) findViewById(R.id.button);

button.setOnClickListener(this);

}

@Override

public void onClick(View v) {

showCustomDialog();

}

public void showCustomDialog() {

AlertDialog.Builder builder;

AlertDialog alertDialog;

Context mContext = MainActivity.this;

LayoutInflater inflater = (LayoutInflater) mContext

.getSystemService(LAYOUT_INFLATER_SERVICE);

View layout = inflater.inflate(R.layout.custom_dialog, null);

TextView text = (TextView) layout.findViewById(R.id.text);

text.setText("Hello, Welcome to Mr Wei's blog!");

ImageView image = (ImageView) layout.findViewById(R.id.image);

image.setImageResource(R.drawable.icon);

builder = new AlertDialog.Builder(mContext);

builder.setView(layout);

alertDialog = builder.create();

alertDialog.show();

}

}

TabSpec与TabHost

TabHost相当于浏览器中浏览器分布的集合，而Tabspec则相当于浏览器中的每个分页面。d在Android中，每个TabSpec分布能够是一个组件，也能够是一个布局，然后将每个分页装入TabHost中，TabHost就可以将当中的每个分页一并显示出来

Android 中的Tabhost控件是个挺好用的控件，像一些分模块展示的页面就能够用Tabhost。

Tabhost的主要是由TabSpac组成的选项卡集合。TabSpec主要有两个重要方法，看代码：

​

2. /**
3. * A tab has a tab indicator, content, and a tag that is used to keep
4. * track of it. This builder helps choose among these options.
5. *
6. * For the tab indicator, your choices are:
7. * 1) set a label
8. * 2) set a label and an icon
9. *
10. * For the tab content, your choices are:
11. * 1) the id of a {@link View}
12. * 2) a {@link TabContentFactory} that creates the {@link View} content.
13. * 3) an {@link Intent} that launches an {@link android.app.Activity}.
14. */
15. public class TabSpec {
16. 
    
17. private String mTag;
18. 
    
19. private IndicatorStrategy mIndicatorStrategy;
20. private ContentStrategy mContentStrategy;
21. 
    
22. private TabSpec(String tag) {
23. mTag = tag;
24. }
25. 
    
26. /**
27. * Specify a label as the tab indicator.
28. */
29. public TabSpec setIndicator(CharSequence label) {
30. mIndicatorStrategy = new LabelIndicatorStrategy(label);
31. return this;
32. }
33. 
    
34. /**
35. * Specify a label and icon as the tab indicator.
36. */
37. public TabSpec setIndicator(CharSequence label, Drawable icon) {
38. mIndicatorStrategy = new LabelAndIconIndicatorStrategy(label, icon);
39. return this;
40. }
41. 
    
42. /**
43. * Specify a view as the tab indicator.
44. */
45. public TabSpec setIndicator(View view) {
46. mIndicatorStrategy = new ViewIndicatorStrategy(view);
47. return this;
48. }
49. 
    
50. /**
51. * Specify the id of the view that should be used as the content
52. * of the tab.
53. */
54. public TabSpec setContent(int viewId) {
55. mContentStrategy = new ViewIdContentStrategy(viewId);
56. return this;
57. }
58. 
    
59. /**
60. * Specify a {@link android.widget.TabHost.TabContentFactory} to use to
61. * create the content of the tab.
62. */
63. public TabSpec setContent(TabContentFactory contentFactory) {
64. mContentStrategy = new FactoryContentStrategy(mTag, contentFactory);
65. return this;
66. }
67. 
    
68. /**
69. * Specify an intent to use to launch an activity as the tab content.
70. */
71. public TabSpec setContent(Intent intent) {
72. mContentStrategy = new IntentContentStrategy(mTag, intent);
73. return this;
74. }

/**
     * A tab has a tab indicator, content, and a tag that is used to keep
     * track of it.  This builder helps choose among these options.
     *
     * For the tab indicator, your choices are:
     * 1) set a label
     * 2) set a label and an icon
     *
     * For the tab content, your choices are:
     * 1) the id of a {@link View}
     * 2) a {@link TabContentFactory} that creates the {@link View} content.
     * 3) an {@link Intent} that launches an {@link android.app.Activity}.
     */
    public class TabSpec {

        private String mTag;

        private IndicatorStrategy mIndicatorStrategy;
        private ContentStrategy mContentStrategy;

        private TabSpec(String tag) {
            mTag = tag;
        }

        /**
         * Specify a label as the tab indicator.
         */
        public TabSpec setIndicator(CharSequence label) {
            mIndicatorStrategy = new LabelIndicatorStrategy(label);
            return this;
        }

        /**
         * Specify a label and icon as the tab indicator.
         */
        public TabSpec setIndicator(CharSequence label, Drawable icon) {
            mIndicatorStrategy = new LabelAndIconIndicatorStrategy(label, icon);
            return this;
        }

        /**
         * Specify a view as the tab indicator.
         */
        public TabSpec setIndicator(View view) {
            mIndicatorStrategy = new ViewIndicatorStrategy(view);
            return this;
        }

        /**
         * Specify the id of the view that should be used as the content
         * of the tab.
         */
        public TabSpec setContent(int viewId) {
            mContentStrategy = new ViewIdContentStrategy(viewId);
            return this;
        }

        /**
         * Specify a {@link android.widget.TabHost.TabContentFactory} to use to
         * create the content of the tab.
         */
        public TabSpec setContent(TabContentFactory contentFactory) {
            mContentStrategy = new FactoryContentStrategy(mTag, contentFactory);
            return this;
        }

        /**
         * Specify an intent to use to launch an activity as the tab content.
         */
        public TabSpec setContent(Intent intent) {
            mContentStrategy = new IntentContentStrategy(mTag, intent);
            return this;
        }

setIndicator（）能够设置选项卡得图标和文字。

须要注意几点是： 1、假设你的Tabhost是从xml文件里findViewById()得到的，

TabWidget 必须为 android:id="@android:id/tabs" ，

FrameLayout android:id="@android:id/tabcontent" ；

2. <TabHost android:id="@+id/tabhost_info" android:layout_width="fill_parent"
3. android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">
4. 
   
5. <LinearLayout android:id="@+id/linearLayout"
6. android:layout_width="fill_parent" android:layout_height="fill_parent"
7. android:orientation="vertical">
8. <TabWidget android:id="@android:id/tabs"
9. android:layout_width="fill_parent" android:layout_height="wrap_content">
10. </TabWidget>
11. <FrameLayout android:id="@android:id/tabcontent"
12. android:layout_width="fill_parent" android:layout_height="wrap_content"
13. android:layout_gravity="fill">
14. <include android:id="@+id/info_include01" layout="@layout/info_layout01" />
15. <include android:id="@+id/info_include02" layout="@layout/info_layout02" />
16. <include android:id="@+id/info_include03" layout="@layout/info_layout03" />
17. 
    
18. </FrameLayout>
19. </LinearLayout>
20. 
    
21. </TabHost>

<TabHost android:id="@+id/tabhost_info" android:layout_width="fill_parent"
  android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">

  <LinearLayout android:id="@+id/linearLayout"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:orientation="vertical">
    <TabWidget android:id="@android:id/tabs"
      android:layout_width="fill_parent" android:layout_height="wrap_content">
    </TabWidget>
    <FrameLayout android:id="@android:id/tabcontent"
      android:layout_width="fill_parent" android:layout_height="wrap_content"
      android:layout_gravity="fill">
      <include android:id="@+id/info_include01" layout="@layout/info_layout01" />
      <include android:id="@+id/info_include02" layout="@layout/info_layout02" />
      <include android:id="@+id/info_include03" layout="@layout/info_layout03" />

    </FrameLayout>
  </LinearLayout>

</TabHost>

2、代码中，在加入TabWidget前，须要调用setup()方法。

​

2. tabHost=(TabHost)findViewById(R.id.tabhost_info);
3. tabHost.setup();
4. tabHost.addTab(tabHost.newTabSpec("信息")
5. .setContent(R.id.info_include01)
6. .setIndicator("基本信息",getResources().getDrawable(R.drawable.ic_launcher))
7. 
   
8. );
9. tabHost.addTab(tabHost.newTabSpec("很多其它信息")
10. .setContent(R.id.info_include02)
11. .setIndicator("很多其它信息",getResources().getDrawable(R.drawable.ic_launcher))
12. 
    
13. 
    
14. tabHost.addTab(tabHost.newTabSpec("附件下载")
15. .setContent(R.id.info_include03)
16. .setIndicator("附件下载",getResources().getDrawable(R.drawable.ic_launcher))
17. 
    

tabHost=(TabHost)findViewById(R.id.tabhost_info);
      tabHost.setup(); 
      tabHost.addTab(tabHost.newTabSpec("信息")
                   .setContent(R.id.info_include01)
                   .setIndicator("基本信息",getResources().getDrawable(R.drawable.ic_launcher))

      );
      tabHost.addTab(tabHost.newTabSpec("很多其它信息")
               .setContent(R.id.info_include02)
               .setIndicator("很多其它信息",getResources().getDrawable(R.drawable.ic_launcher))

  );
      tabHost.addTab(tabHost.newTabSpec("附件下载")
               .setContent(R.id.info_include03)
               .setIndicator("附件下载",getResources().getDrawable(R.drawable.ic_launcher))

  );