-1
我建立了一個簡單的，自定義View類顯示五個彩色圓圈和/或十字架，即呈現Fragment，並充當RecyclerView頂部的固定標題。整個事件放在ViewPager裏面，另外一個Fragment（在ViewPager裏有兩個Fragment，這是第一個）。自定義視圖棒棒糖ViewPager內，只有當不可見
我遇到的問題發生在我的棒棒糖設備上。無論何時加載UI，無論是第一次還是從配置更改，這View拒絕呈現。但奇怪的是，如果我將ViewPager移動到第二個Fragment（以便包含此View的那個不再可見）並啓動配置更改，則當我跳回View時突然顯示爲正常。
我很難過。我已經在佈局中試過其他自定義的View類，並且它們都可以正確渲染，所以它暗示了我的代碼對於這個類特別錯誤。
這裏是我的View類的代碼：
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，爲什麼這View導致的問題：從我MathUtils類使用的兩種方法
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（）'被稱爲在所有的時候，你所得到的無效輸出？如果您嘗試在層次結構視圖或** uiautomatorviewer **中查看輸出結果，那麼該視圖會在該點呈現？如果不是，這些工具發現的視圖狀態有沒有什麼有趣的地方（例如，它被定位在屏幕外）？ – CommonsWare
@CommonsWare調用'onDraw（）'，對於'getWidth（）'，'getHeight（）'，'radius'等調用相同的結果，不管圓圈是否出現。該視圖每次都在Hierarchy View中呈現，但結果與屏幕上的內容不一致。有時候會說在離線時（在配置更改後的ViewPager的第一頁），這些圓形在層次視圖中呈現，但當我選擇第一頁時消失。 – PPartisan
@CommonsWare我也注意到，如果我設置了背景顏色，那麼它每次都會出現。只有在我的'HintTrackerView'不在屏幕上的情況下開始配置更改時纔會出現圓形和十字形。 – PPartisan