我写了一个自定义图像视图来显示信用卡。要创建信用卡,我有一个基本图像,并且我有设置 PAN、持卡人、到期的设置器。此文本需要绘制在基卡图像之上。我的问题是保持文本的位置和大小,以便无论基本图像的大小如何变化,它都看起来总是正确的。我唯一可以依靠的是图像的纵横比与普通信用卡相同。
我的自定义 ImageView
public class CardView extends ImageView {
private String mPan = "4321 0123 4567 8910";
private String mExpiry = "01/16";
private String mCardholder = "MR JOHN SMITH";
private float mPanTextSize = 22;
private float mOtherTextSize = 14;
private Paint mPanPaint = new Paint();
private Paint mCardholderPaint = new Paint();
public CardView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initCardView();
}
public CardView(Context context, AttributeSet attrs) {
super(context, attrs);
initCardView();
}
public CardView(Context context) {
super(context);
initCardView();
}
private final void initCardView() {
mPanPaint.setColor(0xFFFFFFFF);
mPanPaint.setShadowLayer(1, 1, 1, 0xAA000000);
mPanPaint.setAntiAlias(true);
mPanPaint.setTextSize(mPanTextSize * getResources().getDisplayMetrics().scaledDensity);
mPanPaint.setTypeface(Typeface.MONOSPACE);
mCardholderPaint.setColor(0xFFFFFFFF);
mCardholderPaint.setShadowLayer(1, 1, 1, 0xAA000000);
mCardholderPaint.setAntiAlias(true);
mCardholderPaint.setTextSize(mOtherTextSize * getResources().getDisplayMetrics().scaledDensity);
mCardholderPaint.setTypeface(Typeface.MONOSPACE);
setPadding(0,0,0,0);
//setAdjustViewBounds(true);
setScaleType(ImageView.ScaleType.CENTER_INSIDE);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
float panLength = mPanPaint.measureText(mPan);
float x = (getWidth() - panLength)/2;
float y = -mPanPaint.ascent() + (getHeight() * 0.46f);
canvas.drawText(mPan, x, y, mPanPaint);
x = (getWidth() - panLength)/1.5f;
y = y - mCardholderPaint.ascent();
canvas.drawText(mExpiry, x, y, mCardholderPaint);
y = y - mCardholderPaint.ascent();
canvas.drawText(mCardholder, x, y, mCardholderPaint);
//super.onDraw(canvas);
}
public void setPan(String pan) {
mPan = pan;
invalidate();
}
public String getPan() {
return mPan;
}
public void setExpiry(String expiry) {
mExpiry = expiry;
invalidate();
}
public String getExpiry() {
return mExpiry;
}
public void setCardholder(String cardholder) {
mCardholder = cardholder;
invalidate();
}
public String getCardholder() {
return mCardholder;
}
}
所以有时这看起来不错,但是当你使用 10 英寸屏幕时,文本太小了,就在图像的中心(想象一下信用卡,但数字只占用中间 8 位数字的空间),并且当您进入小屏幕时,文本太大了,一直到图像两侧或经过它们。
有什么解决办法吗?任何解释为什么?