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;
}

}