我正在绘制UIImage
s到/来自电网。我目前只绘制的变化......而只有改变......但旧的图像都应该留在原地......然而现在他们的drawRect:(CGRect)rect:
如何绘制上下文而不会丢失?
- (void)drawRect:(CGRect)rect
{
int cellSize = self.bounds.size.width/WIDTH;
double xOffset = 0;
CGRect cellFrame = CGRectMake(0, 0, cellSize, cellSize);
NSUInteger cellIndex = 0;
cellFrame.origin.x = xOffset;
for (int i = 0; i < WIDTH; i++)
{
cellFrame.origin.y = 0;
for (int j = 0; j < HEIGHT; j++, cellIndex++)
{
if([[self.state.boardChanges objectAtIndex:(i*HEIGHT)+j] intValue]==1){
if (CGRectIntersectsRect(rect, cellFrame)) {
NSNumber *currentCell = [self.state.board objectAtIndex:cellIndex];
if (currentCell.intValue == 1)
{
[image1 drawInRect:cellFrame];
}
else if (currentCell.intValue == 0)
{
[image2 drawInRect:cellFrame];
}
}
}
cellFrame.origin.y += cellSize;
}
cellFrame.origin.x += cellSize;
}
}
我的下一个电话后消失尝试了以下的混合物没有任何结果: