一个很酷的加载loading效果，自定义LeafLoadingView实现，LeafLoadingView继承view,
本例子主要由以下几点构成
（1）：RotateAnimation实现叶子旋转
（2）：叶子飘动
（3）：当前进度绘制当前进度条
大体实现：
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// 绘制进度条和叶子
// 之所以把叶子放在进度条里绘制，主要是层级原因
drawProgressAndLeafs(canvas);
// drawLeafs(canvas);
canvas.drawBitmap(mOuterBitmap, mOuterSrcRect, mOuterDestRect, mBitmapPaint);
postInvalidate();
}
private void drawProgressAndLeafs(Canvas canvas) {
if (mProgress >= TOTAL_PROGRESS) {
mProgress = 0;
}
// mProgressWidth为进度条的宽度，根据当前进度算出进度条的位置
mCurrentProgressPosition = mProgressWidth * mProgress / TOTAL_PROGRESS;
// 即当前位置在图中所示1范围内
if (mCurrentProgressPosition < mArcRadius) {
Log.i(TAG, "mProgress = " + mProgress + "---mCurrentProgressPosition = "
+ mCurrentProgressPosition
+ "--mArcProgressWidth" + mArcRadius);
// 1.绘制白色ARC，绘制orange ARC
// 2.绘制白色矩形
// 1.绘制白色ARC
canvas.drawArc(mArcRectF, 90, 180, false, mWhitePaint);
// 2.绘制白色矩形
mWhiteRectF.left = mArcRightLocation;
canvas.drawRect(mWhiteRectF, mWhitePaint);
// 绘制叶子
drawLeafs(canvas);
// 3.绘制棕色 ARC
// 单边角度
int angle = (int) Math.toDegrees(Math.acos((mArcRadius - mCurrentProgressPosition)
/ (float) mArcRadius));
// 起始的位置
int startAngle = 180 - angle;
// 扫过的角度
int sweepAngle = 2 * angle;
Log.i(TAG, "startAngle = " + startAngle);
canvas.drawArc(mArcRectF, startAngle, sweepAngle, false, mOrangePaint);
} else {
Log.i(TAG, "mProgress = " + mProgress + "---transfer-----mCurrentProgressPosition = "
+ mCurrentProgressPosition
+ "--mArcProgressWidth" + mArcRadius);
// 1.绘制white RECT
// 2.绘制Orange ARC
// 3.绘制orange RECT
// 这个层级进行绘制能让叶子感觉是融入棕色进度条中
// 1.绘制white RECT
mWhiteRectF.left = mCurrentProgressPosition;
canvas.drawRect(mWhiteRectF, mWhitePaint);
// 绘制叶子
drawLeafs(canvas);
// 2.绘制Orange ARC
canvas.drawArc(mArcRectF, 90, 180, false, mOrangePaint);
// 3.绘制orange RECT
mOrangeRectF.left = mArcRightLocation;
mOrangeRectF.right = mCurrentProgressPosition;
canvas.drawRect(mOrangeRectF, mOrangePaint);
}
}
/**
* 绘制叶子
*
* @param canvas
*/
private void drawLeafs(Canvas canvas) {
mLeafRotateTime = mLeafRotateTime <= 0 ? LEAF_ROTATE_TIME : mLeafRotateTime;
long currentTime = System.currentTimeMillis();
for (int i = 0; i < mLeafInfos.size(); i++) {
Leaf leaf = mLeafInfos.get(i);
if (currentTime > leaf.startTime && leaf.startTime != 0) {
// 绘制叶子－－根据叶子的类型和当前时间得出叶子的（x，y）
getLeafLocation(leaf, currentTime);
// 根据时间计算旋转角度
canvas.save();
// 通过Matrix控制叶子旋转
Matrix matrix = new Matrix();
float transX = mLeftMargin + leaf.x;
float transY = mLeftMargin + leaf.y;
Log.i(TAG, "left.x = " + leaf.x + "--leaf.y=" + leaf.y);
matrix.postTranslate(transX, transY);
// 通过时间关联旋转角度，则可以直接通过修改LEAF_ROTATE_TIME调节叶子旋转快慢
float rotateFraction = ((currentTime - leaf.startTime) % mLeafRotateTime)
/ (float) mLeafRotateTime;
int angle = (int) (rotateFraction * 360);
// 根据叶子旋转方向确定叶子旋转角度
int rotate = leaf.rotateDirection == 0 ? angle + leaf.rotateAngle : -angle
+ leaf.rotateAngle;
matrix.postRotate(rotate, transX
+ mLeafWidth / 2, transY + mLeafHeight / 2);
canvas.drawBitmap(mLeafBitmap, matrix, mBitmapPaint);
canvas.restore();
} else {
continue;
}
}
}
运行效果：
【Android教程】一个很酷的加载loading效果
原文链接： https://my.oschina.net/u/2489985/blog/531968
转载于:https://my.oschina.net/u/2489985/blog/531968