Android开发--Matrix（二）--实现图片的旋转

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:background="@drawable/white"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:id="@+id/myTextView1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#ff0000"
android:text="@string/app_name"/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
<Button
android:id="@+id/myButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/str_button1" />
<ImageView
android:id="@+id/myImageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" />
<Button
android:id="@+id/myButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/str_button2" />
</LinearLayout>
</LinearLayout>

public class EX04_24 extends Activity
{
private Button mButton1;
private Button mButton2;
private TextView mTextView1;
private ImageView mImageView1;
private int ScaleTimes; private int ScaleAngle;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

mButton1 =(Button) findViewById(R.id.myButton1);
mButton2 =(Button) findViewById(R.id.myButton2);
mTextView1 = (TextView) findViewById(R.id.myTextView1);
mImageView1 = (ImageView) findViewById(R.id.myImageView1);

//定义旋转的角度和图像转变的比例（大小）
ScaleTimes = 1;
ScaleAngle = 1;

final Bitmap mySourceBmp =
BitmapFactory.decodeResource(getResources(), R.drawable.hippo);

final int widthOrig = mySourceBmp.getWidth();
final int heightOrig = mySourceBmp.getHeight();

/* 程序刚执行，加载默认的Drawable */
mImageView1.setImageBitmap(mySourceBmp);

/* 向左选转按钮 */
mButton1.setOnClickListener(new Button.OnClickListener()
{

@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
ScaleAngle--;
if(ScaleAngle<-5)
{
ScaleAngle = -5;
}

/* ScaleTimes=1，维持1:1的宽高比例*/
int newWidth = widthOrig * ScaleTimes;
int newHeight = heightOrig * ScaleTimes;

float scaleWidth = ((float) newWidth) / widthOrig;
float scaleHeight = ((float) newHeight) / heightOrig;

Matrix matrix = new Matrix();
/* 使用Matrix.postScale设定维度 */
matrix.postScale(scaleWidth, scaleHeight);
/* 使用Matrix.postRotate方法旋转Bitmap*/
//matrix.postRotate(5*ScaleAngle);
matrix.setRotate(5*ScaleAngle);
/* 建立新的Bitmap对象 */
Bitmap resizedBitmap =
Bitmap.createBitmap(mySourceBmp, 0, 0, widthOrig, heightOrig, matrix, true);
/**/
BitmapDrawable myNewBitmapDrawable =
new BitmapDrawable(resizedBitmap);
mImageView1.setImageDrawable(myNewBitmapDrawable);
mTextView1.setText(Integer.toString(5*ScaleAngle));
}
});
/* 向右选转按钮 */
mButton2.setOnClickListener(new Button.OnClickListener()
{
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
ScaleAngle++;
if(ScaleAngle>5)
{
ScaleAngle = 5;
}
/* ScaleTimes=1，维持1:1的宽高比例*/
int newWidth = widthOrig * ScaleTimes;
int newHeight = heightOrig * ScaleTimes;
/* 计算旋转的Matrix比例 */
float scaleWidth = ((float) newWidth) / widthOrig;
float scaleHeight = ((float) newHeight) / heightOrig;
Matrix matrix = new Matrix();
/* 使用Matrix.postScale设定维度 */
matrix.postScale(scaleWidth, scaleHeight);
/* 使用Matrix.postRotate方法旋转Bitmap*/
//matrix.postRotate(5*ScaleAngle);
matrix.setRotate(5*ScaleAngle);
/* 建立新的Bitmap对象 */
Bitmap resizedBitmap =
Bitmap.createBitmap(mySourceBmp, 0, 0, widthOrig, heightOrig, matrix, true);
/**/ BitmapDrawable myNewBitmapDrawable =
new BitmapDrawable(resizedBitmap);
mImageView1.setImageDrawable(myNewBitmapDrawable);
mTextView1.setText(Integer.toString(5*ScaleAngle));
}
});
}
}