我希望能够将图片顺时针和逆时针旋转。
我已经尝试过但无法同时进行两种方式的旋转。
如果您知道如何解决我的问题,请给予解决方案。
提前感谢。///
public class Rotateimage extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_gallery);
// or just load a resource from the res/drawable directory:
Bitmap myBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.flo);
// find the width and height of the screen:
Display d = getWindowManager().getDefaultDisplay();
int x = d.getWidth();
int y = d.getHeight();
// get a reference to the ImageView component that will display the image:
ImageView img1 = (ImageView)findViewById(R.id.imageView1);
// scale it to fit the screen, x and y swapped because my image is wider than it is tall
Bitmap scaledBitmap = Bitmap.createScaledBitmap(myBitmap, y, x, true);
// create a matrix object
Matrix matrix = new Matrix();
matrix.postRotate(45, 90, 180);
// create a new bitmap from the original using the matrix to transform the result
Bitmap rotatedBitmap = Bitmap.createBitmap(scaledBitmap , 0, 0, scaledBitmap .getWidth(), scaledBitmap .getHeight(), matrix, true);
// display the rotated bitmap
img1.setImageBitmap(rotatedBitmap);
}}
// Load a bitmap from a drawable, make sure this drawable exists in your project
Bitmap sprite = BitmapFactory.decodeResource(this.getResources(),
R.drawable.ic_launcher);
// Create two matrices that will be used to rotate the bitmap
Matrix rotateRight = new Matrix();
Matrix rotateLeft = new Matrix();
// Set the matrices with the desired rotation 90 or -90 degrees
rotateRight.preRotate(90);
rotateLeft.preRotate(-90);
// Create bitmaps based on the loaded bitmap 'sprite' and apply one of
// the rotation matrices
Bitmap rSprite = Bitmap.createBitmap(sprite, 0, 0,
sprite.getWidth(), sprite.getHeight(), rotateRight, true);
Bitmap lSprite = Bitmap.createBitmap(sprite, 0, 0,
sprite.getWidth(), sprite.getHeight(), rotateLeft, true);
现在使用rSprite和lSprite。
这是一个完整的示例,实际将位图绘制到屏幕上:
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new drawView(this));
}
private class drawView extends View{
public drawView(Context context){
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// Load a bitmap from a drawable, make sure this drawable exists in your project
Bitmap sprite = BitmapFactory.decodeResource(this.getResources(),
R.drawable.ic_launcher);
// Create two matrices that will be used to rotate the bitmap
Matrix rotateRight = new Matrix();
Matrix rotateLeft = new Matrix();
// Set the matrices with the desired rotation 90 or -90 degrees
rotateRight.preRotate(90);
rotateLeft.preRotate(-90);
// Create bitmaps based on the loaded bitmap 'sprite' and apply one of
// the rotation matrices
Bitmap rSprite = Bitmap.createBitmap(sprite, 0, 0,
sprite.getWidth(), sprite.getHeight(), rotateRight, true);
Bitmap lSprite = Bitmap.createBitmap(sprite, 0, 0,
sprite.getWidth(), sprite.getHeight(), rotateLeft, true);
//Draw the first unrotated sprite at the top left of the screen
canvas.drawBitmap(sprite, 0, 0, null);
//Draw the rotated right sprite on the 2nd row
canvas.drawBitmap(rSprite, 0, sprite.getHeight() + 5, null);
//Draw the rotated left sprite on the 3rd row
canvas.drawBitmap(lSprite, 0, sprite.getHeight() * 2 + 5, null);
}
}
}
你只需要将这段简单的代码添加到你的按钮中
imVCature_pic.setRotation(imVCature_pic.getRotation() + 90);
使用这段代码,希望它能有所帮助... 你必须编写这个方法来执行旋转操作
public void paintFromCenter(float angle, Canvas c) {
Bitmap b = sprite;
Bitmap h = b;
Matrix matrix = new Matrix();
matrix.postRotate(angle, h.getWidth() / 2, h.getHeight());
matrix.postTranslate(getX(), getY());
// canvas.drawBitmap(bitmap, matrix, new Paint());
Bitmap bmp2 = Bitmap.createBitmap(h, 0, 0, frameWidth, frameHeight,
matrix, true);
c.drawBitmap(h, matrix, null);
}
public boolean onTouchEvent(MotionEvent event) {
int action = event.getAction();
if (action == MotionEvent.ACTION_DOWN) {
edX = (int) event.getX();
edY = (int) event.getY();
if ((edX > objectSprite.getX()
&& edX < objectSprite.getX() + objectSprite.getWidth()
&& edY > objectSprite.getY() && edY < objectSprite.getY()
+ objectSprite.getHeight())) {
}
}
if (action == MotionEvent.ACTION_MOVE) {
emX = (int) event.getX();
emY = (int) event.getY();
if (edX < emX && angle <= 90) {
update(canvas);
CHAR = 'D';
} else if (edX > emX && angle > 0) {
update(canvas);
CHAR = 'U';
}
if (edY < emY && angle <= 90) {
update(canvas);
CHAR = 'L';
} else if (edY > emY && angle >= 0) {
update(canvas);
CHAR = 'R';
}
}
return true;
}
你需要创建一个update()方法,在触摸事件中旋转你的角度,角度可以根据你的选择定义。最初我已经声明了
int angle=1;
public void update(Canvas canvas) {
switch (CHAR) {
case 'D':
angle += 1;
break;
case 'U':
angle -= 1;
break;
case 'R':
angle -= 1;
break;
case 'L':
angle += 1;
break;
}
}
public void draw() {
objectSprite.paintFromCenter(angle, canvas);
}
Matrix mat = new Matrix();
mat.preRotate(angle);///in degree
Bitmap mBitmap = Bitmap.createBitmap(originalBmp, 0, 0, modWidth, modHeight, mat, true);
//originalBmp -> original img as bitmap
//modHeight -> new height
//modWidth -> new width