在这段代码中,我想在两个ImageView的顶部之间绘制一条线。 但是,在调用
以下是我的代码:
调用
invalidate()
后,运行应用程序时,自定义视图会显示为纯黑色。以下是我的代码:
public class ArrowView extends RelativeLayout {
public Paint paint;
public Bitmap eraser;
public Canvas cacheCanvas;
public float leftX;
public float leftY;
public float rightX;
public float rightY;
public boolean update = false;
public ImageView iv_leftArrow;
public ImageView iv_rightArrow;
private int w;
private int h;
LayoutInflater mInflater;
public ArrowView(Context context) {
super(context);
this.setWillNotDraw(false);
mInflater = LayoutInflater.from(context);
init();
}
public ArrowView(Context context, AttributeSet attrs) {
super(context, attrs);
this.setWillNotDraw(false);
mInflater = LayoutInflater.from(context);
init();
}
public ArrowView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.setWillNotDraw(false);
mInflater = LayoutInflater.from(context);
init();
}
@Override
public void onSizeChanged(int w, int h, int oldW, int oldH) {
this.w = w;
this.h = h;
super.onSizeChanged(w, h, oldW, oldH);
}
public void init() {
View v = mInflater.inflate(R.layout.arrow_view, this, true);
paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(Color.BLACK);
paint.setStrokeWidth(5);
v.setBackgroundColor(Color.TRANSPARENT);
eraser = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
iv_leftArrow = (ImageView) v.findViewById(R.id.iv_leftarrow);
iv_rightArrow = (ImageView) v.findViewById(R.id.iv_rightArrow);
cacheCanvas = new Canvas();
cacheCanvas.setBitmap(eraser);
}
public void setCoordinates(float leftX, float leftY, float rightX, float rightY) {
this.leftX = leftX;
this.leftY = leftY;
this.rightX = rightX;
this.rightY = rightY;
}
@Override
public void onDraw(Canvas c) {
super.onDraw(c);
setCoordinates(iv_leftArrow.getX() + iv_leftArrow.getWidth() / 2, iv_leftArrow.getY(), iv_rightArrow.getX() + iv_rightArrow.getWidth() / 2, iv_rightArrow.getY() );
if (update) {
c.drawLine(leftX, leftY, rightX, rightY, paint);
update = false;
}
cacheCanvas.drawPath(p, paint);
}
}
调用
invalidate()
后,自定义视图显示为纯黑色的原因是什么?
invalidate()
之前设置的。也许我会尝试在调用“CollectingDetail”的setArrow()
之前调用它。 - Pink JazzcacheCanvas.drawPath(p, paint);
中,你如何找到p的值? - Khairul Alam Liconupdate
的更改移动到setArrow()
之前就解决了问题。我该如何颁发赏金? - Pink JazzsetBackgroundColor(Color.TRANSPARENT)
(不使用v实例)将视图的背景设置为透明。 - racs