Android开发05—Android常用高级控件（下）

Android开发05—Android常用高级控件（下）

1. 滑块与进度条
1） ProgressBar类
ProgressBar类同样位于android.widget包下，但其继承自View，主要用于显示一些操作的进度。应用程序可以修改其长度表示当前后台操作的完成情况。因为进度条会移动，所以长时间加载某些资源或者执行某些耗时的操作时，不会使用户界面失去响应。

2） SeekBar类
SeekBar类继承自ProgressBar，是用来接收用户输入的控件。SeekBar类似于拖拉条，可以直观地显示用户需要的数据，常用于音量调节等场合。
3） 实例：
main.xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:id="@+id/linearLayout1">
        <ProgressBar android:id="@+id/progressBar1" android:layout_height="wrap_content" android:layout_width="fill_parent" android:max="100" android:progress="20" style="@android:style/Widget.ProgressBar.Horizontal"></ProgressBar>
        <RatingBar android:layout_height="wrap_content" android:layout_width="wrap_content" android:max="5"  android:rating="1" android:id="@+id/ratingBar1"></RatingBar>
    </LinearLayout>

Activity:

package qijia.si;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ProgressBar;
import android.widget.RatingBar;

public class JavaTest extends Activity {
    /** Called when the activity is first created. */
	final static double MAX = 100;
	final static double MAX_STAR = 5;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        RatingBar rb = (RatingBar) findViewById(R.id.ratingBar1);
        
        rb.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() {
			
			public void onRatingChanged(RatingBar ratingBar, float rating,
					boolean fromUser) {
				// TODO Auto-generated method stub
				ProgressBar pb = (ProgressBar) findViewById(R.id.progressBar1);
				RatingBar rb = (RatingBar) findViewById(R.id.ratingBar1);
				float rate = rb.getRating();
				pb.setProgress((int)(rate/MAX_STAR*MAX));
			}
		});
    }
}

2. 选项卡
TabHost类位于android.widget包下，是选项卡的封装类，用于创建创建选项卡的窗口。TabHost继承自FrameLayout是帧布局的一种。
实例：
main.xml:

<?xml version="1.0" encoding="utf-8"?>
    <FrameLayout android:id="@+id/frameLayout1" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">
        <LinearLayout android:id="@+id/linearLayout1" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center_horizontal" android:orientation="vertical">
            <ImageView android:layout_height="wrap_content" android:layout_width="wrap_content" android:id="@+id/imageView1" android:scaleType="fitXY" android:layout_gravity="center" android:src="@drawable/andy"></ImageView>
            <TextView android:layout_height="wrap_content" android:id="@+id/textView1" android:layout_width="wrap_content" android:text="@string/andy" android:textSize="24dip"></TextView>
        </LinearLayout>
        <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center_horizontal" android:orientation="vertical" android:id="@+id/linearLayout2">
            <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/imageView2" android:scaleType="fitXY" android:layout_gravity="center" android:src="@drawable/bill"></ImageView>
            <TextView android:layout_height="wrap_content" android:text="@string/bill" android:layout_width="wrap_content" android:id="@+id/textView2" android:textSize="24dip"></TextView>
        </LinearLayout>
        <LinearLayout android:layout_width="fill_parent" android:orientation="vertical" android:gravity="center_horizontal" android:layout_height="fill_parent" android:id="@+id/linearLayout3">
            <ImageView android:layout_height="wrap_content" android:layout_width="wrap_content" android:id="@+id/imageView3" android:scaleType="fitXY" android:layout_gravity="center" android:src="@drawable/torvalds"></ImageView>
            <TextView android:layout_height="wrap_content" android:text="@string/linus" android:layout_width="wrap_content" android:id="@+id/textView3" android:textSize="24dip"></TextView>
        </LinearLayout>
    </FrameLayout>

   

Activity:

package qijia.si;

import android.app.Activity;
import android.app.TabActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.widget.ProgressBar;
import android.widget.RatingBar;
import android.widget.TabHost;

public class JavaTest extends TabActivity {
    /** Called when the activity is first created. */
	private TabHost myTabhost;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        myTabhost = this.getTabHost();
        LayoutInflater.from(this).inflate(R.layout.main, myTabhost.getTabContentView(),true);
        myTabhost.addTab(myTabhost.newTabSpec("选项卡1").setIndicator("选项卡1",getResources().getDrawable(R.drawable.png1)).setContent(R.id.linearLayout1));
        myTabhost.addTab(myTabhost.newTabSpec("选项卡2").setIndicator("选项卡2",getResources().getDrawable(R.drawable.png2)).setContent(R.id.linearLayout2));
        myTabhost.addTab(myTabhost.newTabSpec("选项卡3").setIndicator("选项卡3",getResources().getDrawable(R.drawable.png3)).setContent(R.id.linearLayout3));
    }
}

3. 画廊控件
Gallery是一种水平滚动的列表，一般情况下用来显示图片等资源，可以使图片在屏幕上滑来滑去。Gallery所显示的图片资源同样来自适配器。
Gallery是View的子类，Gallery控件可以在XML中配置，也可以再代码中操作。
实例：将需要显示的控件存放在BaseAdapter中，然后在适当的时间将此BaseAdapter设置Gallery控件使之显示。

main.xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:id="@+id/linearLayout1" android:gravity="center_vertical">
        <Gallery android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/gallery1" android:spacing="10dip" android:unselectedAlpha="1"></Gallery>
    </LinearLayout>

Activity：

package qijia.si;

import android.app.Activity;
import android.app.TabActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RatingBar;
import android.widget.TabHost;

public class JavaTest extends Activity {
    /** Called when the activity is first created. */
	int[] imageIds={
			R.drawable.bbta,R.drawable.bbtb,R.drawable.bbtc,
			R.drawable.bbtd,R.drawable.bbte,R.drawable.bbtf,
			R.drawable.bbtg			
	};
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Gallery g1 = (Gallery)this.findViewById(R.id.gallery1);
        BaseAdapter ba = new BaseAdapter(){

			public int getCount() {
				// TODO Auto-generated method stub
				return imageIds.length;
			}

			public Object getItem(int position) {
				// TODO Auto-generated method stub
				return null;
			}

			public long getItemId(int position) {
				// TODO Auto-generated method stub
				return 0;
			}

			public View getView(int position, View convertView, ViewGroup parent) {
				// TODO Auto-generated method stub
				ImageView iv = new ImageView(JavaTest.this);
				
				iv.setImageResource(imageIds[position]);
				iv.setScaleType(ImageView.ScaleType.FIT_XY);
				iv.setLayoutParams(new Gallery.LayoutParams(188,250));
				return iv;
				
			}
        	
        };
        g1.setAdapter(ba);
        g1.setOnItemClickListener(
        	new OnItemClickListener(){

				public void onItemClick(AdapterView<?> arg0, View arg1,
						int arg2, long arg3) {
					// TODO Auto-generated method stub
					Gallery g1 = (Gallery)findViewById(R.id.gallery1);
					g1.setSelection(arg2);
				}
        		
        	});
    } 
}