疯狂java讲义笔记 2.3.7

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/layoutMain"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:gravity="center">

        <Button
            android:id="@+id/upAlpha"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="增大透明度" />

        <Button
            android:id="@+id/downAlpha"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="降低透明度" />

        <Button
            android:id="@+id/next"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="下一张" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >
    </LinearLayout>

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="match_parent"
        android:layout_height="400px"
        android:background="#0000ff"
        android:scaleType="fitCenter"
        android:src="@drawable/camera" />

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="120dp"
        android:layout_height="120dp"
        android:background="#0000ff"
        android:layout_marginTop="10dp"
        android:src="@drawable/camera" />

</LinearLayout>

package com.moon.hello2;

import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

import com.moon.hello2.R.layout;

import android.R.integer;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.Chronometer;
import android.widget.Chronometer.OnChronometerTickListener;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.ToggleButton;

public class MainActivity extends Activity {
    int[] images = new int[] { R.drawable.a1, R.drawable.a2, R.drawable.a3,
            R.drawable.a4, R.drawable.a5 };
    int currentImg = 0;
    int alpha = 255;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.activity_main);
        final ImageView iView = (ImageView) findViewById(R.id.imageView1);
        final ImageView iView2 = (ImageView) findViewById(R.id.imageView2);
        final Button btnUpAlpha = (Button) findViewById(R.id.upAlpha);
        final Button btnDownAlpha = (Button) findViewById(R.id.downAlpha);
        Button btnNext = (Button) findViewById(R.id.next);
        iView.setImageResource(images[this.currentImg]);
        btnNext.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                currentImg++;
                if (currentImg >= images.length) {
                    currentImg = 0;
                }
                BitmapDrawable bitmapDrawable = (BitmapDrawable) iView
                        .getDrawable();
                if (!bitmapDrawable.getBitmap().isRecycled()) {
                    bitmapDrawable.getBitmap().recycle();
                }
                iView.setImageBitmap(BitmapFactory.decodeResource(
                        getResources(), images[currentImg]));
            }
        });
        OnClickListener listener = new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                if (v == btnUpAlpha) {
                    alpha += 20;
                } else if (v == btnDownAlpha) {
                    alpha -= 20;
                } else {
                    ;
                }
                if (alpha > 255) {
                    alpha = 255;
                } else if (alpha < 0) {
                    alpha = 0;
                } else {
                    ;
                }
                iView.setAlpha(alpha);
            }
        };
        btnDownAlpha.setOnClickListener(listener);
        btnUpAlpha.setOnClickListener(listener);
        iView.setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View arg0, MotionEvent event) {
                // TODO Auto-generated method stub
                BitmapDrawable bitmapDrawable = (BitmapDrawable) iView
                        .getDrawable();
                Bitmap bitmap = bitmapDrawable.getBitmap();
                double scale = bitmap.getWidth() / 320.0;
                int x = (int) (event.getX() * scale);
                int y = (int) (event.getY() * scale);
                if(x + 120 > bitmap.getWidth()){
                    x = bitmap.getWidth() - 120;
                }
                if (y + 120 > bitmap.getHeight()) {
                    y = bitmap.getHeight() - 120;
                }
                iView2.setImageBitmap(Bitmap.createBitmap(bitmap,x,y,120,120));
                iView2.setAlpha(alpha);
                return false;
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}