我有一个相对布局，我在其上添加一个视图。这是活动中的代码：
paint = (RelativeLayout) findViewById(R.id.paint);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
myView = new CustomImage(getBaseContext());
paint.addView(myView);
String imagePath = (String) getIntent().getExtras().get("selectedImagePath");
LogService.log("PaintActivity", "Imagepath: " + imagePath);
// Drawable background = BitmapDrawable.createFromPath(imagePath);
// bitmap = ((BitmapDrawable) background).getBitmap();
try {
fis = new FileInputStream(imagePath);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
mBitmap = loadBitmap(fis.getFD());
bitmap = getResizedBitmap(mBitmap, 412*2, 1024*2);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
LogService.log("PaintActivity", "Bitmap = " + mBitmap);
myView.setBitmap(bitmap);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFF000000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(50);
myView.setPaint(mPaint);
}
}, 50);
这是我的观点：
public class CustomImage extends View {
private boolean hasResized = false;
private Bitmap bitmap, bitmap2;
public Context context;
Paint paint;
private Canvas canvas;
public String text = null;
private Paint mBitmapPaint, paintText;
private Path mPath = new Path();
private float mX, mY, pX, pY, tX, tY;
private static final float TOUCH_TOLERANCE = 4;
private float screenDensity;
int height, width;
private Bitmap mBitmap;
private RandomAccessFile randomAccessFile;
private int bh;
private int bw;
public CustomImage(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
public CustomImage(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public CustomImage(Context context) {
super(context);
init(context);
}
private void init(Context context) {
this.context = context;
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
public void setImg(Context context, Canvas canvas, Bitmap bitmapw, int width, int height) {
bw = bitmapw.getWidth();
bh = bitmapw.getHeight();
float scaleWidth = ((float) width)/ bw;
float scaleHeight = ((float) height)/ bh;
System.out.println("CustomImage.setImg()");
bitmap = bitmapw;
}
public void setPaint(Paint paint) {
this.paint = paint;
LogService.log("in setPaint", "paint = " + paint);
}
public void setBitmap(Bitmap bitmap) throws Exception {
File file = new File("/mnt/sdcard/sample/temp.txt");
file.getParentFile().mkdirs();
randomAccessFile = new RandomAccessFile(file, "rw");
int bWidth = bitmap.getWidth();
int bHeight = bitmap.getHeight();
FileChannel channel = randomAccessFile.getChannel();
MappedByteBuffer map = channel.map(MapMode.READ_WRITE, 0, bWidth*bHeight*4);
bitmap.copyPixelsToBuffer(map);
bitmap.recycle();
this.bitmap = Bitmap.createBitmap(bWidth, bHeight, Config.ARGB_8888);
map.position(0);
this.bitmap.copyPixelsFromBuffer(map);
channel.close();
randomAccessFile.close();
// this.bitmap = bitmap;
// canvas = new Canvas();
}
public void setBitmap2(Bitmap bitmap) {
bitmap2 = bitmap;
invalidate();
}
public void getText(String text) {
this.text = text;
paintText = new Paint();
paintText.setColor(0xFFFFFFFF);
paintText.setStrokeWidth(10);
paintText.setTextSize(20);
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(bitmap, 0, 0, mBitmapPaint);
if (PaintActivity.isPic == 1) {
if (bitmap2 != null) {
canvas.drawBitmap(bitmap2, mX, mY, mBitmapPaint);
pX = mX;
pY = mY;
}
if(text != null){
canvas.drawText(text, tX, tY, paintText);
}
} else if (PaintActivity.isPic == 2) {
if(text != null){
canvas.drawText(text, mX, mY, paintText);
tX = mX;
tY = mY;
}
if (bitmap2 != null) {
canvas.drawBitmap(bitmap2, pX, pY, mBitmapPaint);
}
}else{
canvas.drawPath(mPath, paint);
if (bitmap2 != null) {
canvas.drawBitmap(bitmap2, pX, pY, mBitmapPaint);
}
if(text != null){
canvas.drawText(text, tX, tY, paintText);
}
}
}
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
canvas.drawPoint(x, y, paint);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if ((dx >= TOUCH_TOLERANCE) || (dy >= TOUCH_TOLERANCE)) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
mPath.moveTo(mX, mY);
canvas.drawPath(mPath, paint);
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
System.out.println("CustomImage.onSizeChanged()");
super.onSizeChanged(w, h, oldw, oldh);
if ((w != 0) && (h != 0)) {
if (!hasResized) {
hasResized = true;
renderImage();
}
}
}
public void renderImage() {
System.out.println("======in renderimage=======w " + getMeasuredWidth() + "h " + getMeasuredHeight());
width = getMeasuredWidth();
height = getMeasuredHeight();
canvas = new Canvas(bitmap);
setImg(context, canvas, bitmap, width, height);
}
}
如您所见，我在活动中有一个调整大小功能：
public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
int width = bm.getWidth();
int height = bm.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// create a matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);
// recreate the new Bitmap
Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
return resizedBitmap;
}
现在，如果我从代码中评论此功能，图像看起来正常，但没有缩放。如果我把它留在那里，那么我会得到一个丑陋的图像，但它会被调整大小。例： 普通未调整大小：http://imgur.com/BD5Pp,YWDTi 已更改但已调整大小的图片：http://imgur.com/BD5Pp,YWDTi#1
答案 0 :(得分：1)
正如OP所述回答我的问题，位图转换为RGB_565，这是createBitmap() - #16211中的一个已知错误，已在Android 3.0中修复。它也会影响createScaledBitmap()。如果位图保持ARGB_8888，则位图看起来不会失真。
作为一种解决方法，您必须手动创建目标位图（这使您可以完全控制像素格式），然后创建附加到此位图的画布并在其上绘制原始位图的缩放版本。这是我项目的样本：
public class BitmapUtils {
private static Matrix matrix = new Matrix();
private static Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG);
public static final Bitmap resizeBitmap(Bitmap bitmap, float scale, Bitmap.Config targetConfig) {
int srcWidth = bitmap.getWidth();
int srcHeight = bitmap.getHeight();
int newWidth = (int) (srcWidth * scale);
int newHeight = (int) (srcHeight * scale);
float sx = newWidth / (float) srcWidth;
float sy = newHeight / (float) srcHeight;
matrix.setScale(sx, sy);
Bitmap target = Bitmap.createBitmap(newWidth, newHeight, targetConfig);
Canvas c = new Canvas(target);
c.drawBitmap(bitmap, matrix, paint);
return target;
}
}
注意：由于全局matrix实例，此代码不可重入。此外，它需要将比例作为参数，但根据您的需要进行调整（新的宽度/高度作为参数）是微不足道的。