我希望我的位图在我的屏幕中心..我试着这样但它不工作…
Bitmap myBitmap = BitmapFactory.decodeResource(getResources(),R.drawable.compass);
int w = canvas.getWidth();
int h = canvas.getHeight();
int bw=myBitmap.getWidth();
int bh=myBitmap.getHeight();
int cx = w / 2;
int cy = h / 2;
Display d = getWindowManager().getDefaultDisplay();
int x = d.getWidth();
int y = d.getHeight();
int dx = x / 2;
int dw = y /2;
canvas.translate(cx,cy);
if (mValues != null) {
canvas.rotate(-mValues[0]);
}
int centreX = (x - bw) /2;
int centreY = (cy - bh) /2;
//canvas.drawPath(mPath,mPaint);
canvas.drawBitmap(myBitmap,centreX,centreY,null);
解决方法
以下是您在视图中需要的代码：
private int mWidth;
private int mHeight;
private float mAngle;
@Override protected void onMeasure(int widthMeasureSpec,int heightMeasureSpec)
{
mWidth = View.MeasureSpec.getSize(widthMeasureSpec);
mHeight = View.MeasureSpec.getSize(heightMeasureSpec);
setMeasuredDimension(mWidth,mHeight);
}
@Override protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
Bitmap myBitmap = BitmapFactory.decodeResource(getResources(),R.drawable.compass);
// Here's the magic. Whatever way you do it,the logic is:
// space available - bitmap size and divide the result by two.
// There must be an equal amount of pixels on both sides of the image.
// Therefore whatever space is left after displaying the image,half goes to
// left/up and half to right/down. The available space you get by subtracting the
// image's width/height from the screen dimensions. Good luck.
int cx = (mWidth - myBitmap.getWidth()) >> 1; // same as (...) / 2
int cy = (mHeight - myBitmap.getHeight()) >> 1;
if (mAngle > 0) {
canvas.rotate(mAngle,mWidth >> 1,mHeight >> 1);
}
canvas.drawBitmap(myBitmap,cx,cy,null);
}
截图只是为了好玩：http://imgur.com/EYpMJ
(对角线不是此处发布的代码的一部分)
编辑：添加了NickT的解决方案.编辑2：将mvalues [0]更改为mAngle并使其成为条件.将2次操作除以更改为位移.如果您不需要,请删除旋转代码.
