HandlerTimer

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/FrameLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="matrix"
        android:src="@drawable/clock_dial" 
        android:layout_gravity="center"/>

    <ImageView
        android:id="@+id/imageView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="matrix"
        android:layout_gravity="center"
        android:src="@drawable/clock_hour" />

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="matrix"
        android:src="@drawable/clock_mins" 
        android:layout_gravity="center"/>

    <ImageView
        android:id="@+id/imageView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="matrix"
        android:src="@drawable/clock_secs" 
        android:layout_gravity="center"/>

</FrameLayout>

時間變數轉成圖片的旋轉角度

package com.example.app21;

import java.util.Calendar;
import android.app.Activity;
import android.graphics.Matrix;
import android.os.Bundle;
import android.os.Handler;
import android.widget.ImageView;

public class MainActivity extends Activity {
    Handler handler = new Handler();
    ImageView imageView2, imageView3, imageView4;
    Calendar cal;    

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageView2 = (ImageView) this.findViewById(R.id.imageView2);
        imageView3 = (ImageView) this.findViewById(R.id.imageView3);
        imageView4 = (ImageView) this.findViewById(R.id.imageView4);

        handler.post(updateTask);
    }

    Runnable updateTask = new Runnable() {
        @Override
        public void run() {
            // TODO Auto-generated method stub
            cal = Calendar.getInstance(); // 現在的時間
            int secs = cal.get(Calendar.SECOND);
            int mins = cal.get(Calendar.MINUTE);
            int hour = cal.get(Calendar.HOUR);

            int cx = imageView3.getWidth() / 2;
            int cy = imageView3.getHeight() / 2;

            Matrix m = new Matrix();
            m.postRotate(secs * 6, cx, cy);
            imageView3.setImageMatrix(m);

            Matrix m2 = new Matrix();
            m2.postRotate((mins * 6) + ((secs * 6) / 60), cx, cy);
            imageView2.setImageMatrix(m2);

            Matrix m3 = new Matrix();
            m3.postRotate(hour * 30 + ((mins * 30) / 60), cx, cy);
            imageView4.setImageMatrix(m3);

            handler.postDelayed(updateTask, 1000);
        }
    };

    @Override
    protected void onStop() {
        // TODO Auto-generated method stub
        handler.removeCallbacks(updateTask);
        super.onStop();
    }
}