-1
我建立了一个简单的，自定义View类显示五个彩色圆圈和/或十字架，即呈现Fragment，并充当RecyclerView顶部的固定标题。整个事件放在ViewPager里面，另外一个Fragment（在ViewPager里有两个Fragment，这是第一个）。自定义视图棒棒糖ViewPager内，只有当不可见
我遇到的问题发生在我的棒棒糖设备上。无论何时加载UI，无论是第一次还是从配置更改，这View拒绝呈现。但奇怪的是，如果我将ViewPager移动到第二个Fragment（以便包含此View的那个不再可见）并启动配置更改，则当我跳回View时突然显示为正常。
我很难过。我已经在布局中试过其他自定义的View类，并且它们都可以正确渲染，所以它暗示了我的代码对于这个类特别错误。
这里是我的View类的代码：
public static float getHypotenuse(float equalLengths) {
return getHypotenuse(equalLengths, equalLengths);
}
public static float getHypotenuse(float lengthOne, float lengthTwo) {
return (float) (Math.sqrt(Math.pow(lengthOne, 2) + Math.pow(lengthTwo, 2)));
}
public static float getLengthOfFourtyFiveDegreeIsosceles(float hypotenuse) {
return (float) (0.5F*hypotenuse*Math.sqrt(2));
}
任何想法，为什么这View导致的问题：从我MathUtils类使用的两种方法
public class HintTrackerView extends View {
private static final int DEFAULT_NO_OF_CIRCLES = 5;
private static final float DEFAULT_RADIUS_PERCENTAGE = 0.9F;
private static final int[] DEFAULT_ACTIVE_COLOURS = {
PRIMARY_GREEN,
createInterimColor(PRIMARY_GREEN, PRIMARY_ORANGE, 0.25F),
createInterimColor(PRIMARY_GREEN, PRIMARY_ORANGE, 0.5F),
createInterimColor(PRIMARY_GREEN, PRIMARY_ORANGE, 0.75F),
PRIMARY_ORANGE
};
private static final int DEFAULT_INACTIVE_COLOR = PRIMARY_GREY;
private int[] activeColors;
private int inactiveColor;
private Paint mFillPaint, mInactivePaint;
private RectF mRectF;
private float mFillRadius;
private int mNoOfCircles;
public HintTrackerView(Context context) {
super(context, null);
init();
}
public HintTrackerView(Context context, int[] activeColors) {
super(context, null);
init(activeColors);
}
public HintTrackerView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
init(DEFAULT_ACTIVE_COLOURS);
}
private void init(int[] colors) {
this.activeColors = colors;
inactiveColor = DEFAULT_INACTIVE_COLOR;
if (mFillRadius == 0) mFillRadius = DEFAULT_RADIUS_PERCENTAGE;
if (mNoOfCircles == 0) mNoOfCircles = DEFAULT_NO_OF_CIRCLES;
if (colors.length != mNoOfCircles)
throw new IllegalArgumentException("Number of colours must match number of circles");
mFillPaint = new Paint();
mFillPaint.setAntiAlias(true);
mFillPaint.setStyle(Paint.Style.FILL);
mFillPaint.setColor(colors[0]);
mInactivePaint = new Paint();
mInactivePaint.setAntiAlias(true);
mInactivePaint.setDither(true);
mInactivePaint.setStyle(Paint.Style.STROKE);
mInactivePaint.setStrokeCap(Paint.Cap.ROUND);
mInactivePaint.setColor(inactiveColor);
mRectF = new RectF();
}
@Override
protected void onDraw(Canvas canvas) {
final int subCanvasSize = getWidth()/ mNoOfCircles;
for (int i = 0; i < mNoOfCircles; i++) {
mRectF.set(mRectF.right, 0, mRectF.right + subCanvasSize, getHeight());
mFillPaint.setColor(activeColors[i]);
//If hint is has been used, replace symbol with cross
if (i<3) {
drawCircle(canvas, mRectF);
} else {
drawCross(canvas, mRectF);
}
}
}
private void drawCross(Canvas canvas, RectF subCanvasBounds) {
mInactivePaint.setStrokeWidth(MathUtils.getHypotenuse(Math.min(subCanvasBounds.width(), subCanvasBounds.height()) * 0.1F));
float innerSubCanvasBounds = Math.min(subCanvasBounds.width(), subCanvasBounds.height());
float crossLength = MathUtils.getLengthOfFourtyFiveDegreeIsosceles(innerSubCanvasBounds);
float startX, startY, stopX, stopY;
startX = subCanvasBounds.centerX() - (crossLength*0.45F);
startY = subCanvasBounds.centerY() - (crossLength*0.45F);
stopX = subCanvasBounds.centerX() + (crossLength*0.45F);
stopY = subCanvasBounds.centerY() + (crossLength*0.45F);
canvas.drawLine(startX, startY, stopX, stopY, mInactivePaint);
startX = subCanvasBounds.centerX() + (crossLength*0.45F);
startY = subCanvasBounds.centerY() - (crossLength*0.45F);
stopX = subCanvasBounds.centerX() - (crossLength*0.45F);
stopY = subCanvasBounds.centerY() + (crossLength*0.45F);
canvas.drawLine(startX, startY, stopX, stopY, mInactivePaint);
}
private void drawCircle(Canvas canvas, RectF subCanvasBounds) {
float centerX, centerY, radius, viewSize;
centerX = subCanvasBounds.centerX();
centerY = subCanvasBounds.centerY();
viewSize = Math.min(getHeight(), subCanvasBounds.width());
radius = (viewSize/2) * mFillRadius;
canvas.drawCircle(centerX, centerY, radius, mFillPaint);
}
}
而且？
是'的onDraw（）'被称为在所有的时候，你所得到的无效输出？如果您尝试在层次结构视图或** uiautomatorviewer **中查看输出结果，那么该视图会在该点呈现？如果不是，这些工具发现的视图状态有没有什么有趣的地方（例如，它被定位在屏幕外）？ – CommonsWare
@CommonsWare调用'onDraw（）'，对于'getWidth（）'，'getHeight（）'，'radius'等调用相同的结果，不管圆圈是否出现。该视图每次都在Hierarchy View中呈现，但结果与屏幕上的内容不一致。有时候会说在离线时（在配置更改后的ViewPager的第一页），这些圆形在层次视图中呈现，但当我选择第一页时消失。 – PPartisan
@CommonsWare我也注意到，如果我设置了背景颜色，那么它每次都会出现。只有在我的'HintTrackerView'不在屏幕上的情况下开始配置更改时才会出现圆形和十字形。 – PPartisan