There is no prepackaged way to this, you must combine arcs in order to do this, apples quartzdemo project shows the code to do this, here is a reference Quartz Demo and here is the code they provide
// As a bonus, we'll combine arcs to create a round rectangle!
// Drawing with a white stroke color CGContextRef context=UIGraphicsGetCurrentContext() CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0);
// If you were making this as a routine, you would probably accept a rectangle // that defines its bounds, and a radius reflecting the "rounded-ness" of the rectangle. CGRect rrect = CGRectMake(210.0, 90.0, 60.0, 60.0); CGFloat radius = 10.0; // NOTE: At this point you may want to verify that your radius is no more than half // the width and height of your rectangle, as this technique degenerates for those cases.
// In order to draw a rounded rectangle, we will take advantage of the fact that // CGContextAddArcToPoint will draw straight lines past the start and end of the arc // in order to create the path from the current position and the destination position.
// In order to create the 4 arcs correctly, we need to know the min, mid and max positions // on the x and y lengths of the given rectangle. CGFloat minx = CGRectGetMinX(rrect), midx = CGRectGetMidX(rrect), maxx = CGRectGetMaxX(rrect); CGFloat miny = CGRectGetMinY(rrect), midy = CGRectGetMidY(rrect), maxy = CGRectGetMaxY(rrect);
// Next, we will go around the rectangle in the order given by the figure below. // minx midx maxx // miny 2 3 4 // midy 1 9 5 // maxy 8 7 6 // Which gives us a coincident start and end point, which is incidental to this technique, but still doesn't // form a closed path, so we still need to close the path to connect the ends correctly. // Thus we start by moving to point 1, then adding arcs through each pair of points that follows. // You could use a similar tecgnique to create any shape with rounded corners.
// Start at 1 CGContextMoveToPoint(context, minx, midy); // Add an arc through 2 to 3 CGContextAddArcToPoint(context, minx, miny, midx, miny, radius); // Add an arc through 4 to 5 CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius); // Add an arc through 6 to 7 CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius); // Add an arc through 8 to 9 CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius); // Close the path CGContextClosePath(context); // Fill & stroke the path CGContextDrawPath(context, kCGPathFillStroke);
I have a 2.67 GHz Celeron processor, 1.21 GB of RAM on a x86 Windows XP Professional machine. My understanding is that the Android emulator should start fairly quickly on such a machine, but for me it does not. I have followed all instructions in setting up the IDE, SDKs, JDKs and such and have had some success in staring the emulator quickly but is very particulary. How can I, if possible, fix this problem?
I don't think there is a nice predefined way to do this. However, this question has the code necessary to do it using line segments:
ReplyDeletehttp://stackoverflow.com/questions/1031930/how-is-a-rounded-rect-view-with-transparency-done-on-iphone/1031936#1031936
There is no prepackaged way to this, you must combine arcs in order to do this, apples quartzdemo project shows the code to do this, here is a reference Quartz Demo and here is the code they provide
ReplyDelete// As a bonus, we'll combine arcs to create a round rectangle!
// Drawing with a white stroke color
CGContextRef context=UIGraphicsGetCurrentContext()
CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0);
// If you were making this as a routine, you would probably accept a rectangle
// that defines its bounds, and a radius reflecting the "rounded-ness" of the rectangle.
CGRect rrect = CGRectMake(210.0, 90.0, 60.0, 60.0);
CGFloat radius = 10.0;
// NOTE: At this point you may want to verify that your radius is no more than half
// the width and height of your rectangle, as this technique degenerates for those cases.
// In order to draw a rounded rectangle, we will take advantage of the fact that
// CGContextAddArcToPoint will draw straight lines past the start and end of the arc
// in order to create the path from the current position and the destination position.
// In order to create the 4 arcs correctly, we need to know the min, mid and max positions
// on the x and y lengths of the given rectangle.
CGFloat minx = CGRectGetMinX(rrect), midx = CGRectGetMidX(rrect), maxx = CGRectGetMaxX(rrect);
CGFloat miny = CGRectGetMinY(rrect), midy = CGRectGetMidY(rrect), maxy = CGRectGetMaxY(rrect);
// Next, we will go around the rectangle in the order given by the figure below.
// minx midx maxx
// miny 2 3 4
// midy 1 9 5
// maxy 8 7 6
// Which gives us a coincident start and end point, which is incidental to this technique, but still doesn't
// form a closed path, so we still need to close the path to connect the ends correctly.
// Thus we start by moving to point 1, then adding arcs through each pair of points that follows.
// You could use a similar tecgnique to create any shape with rounded corners.
// Start at 1
CGContextMoveToPoint(context, minx, midy);
// Add an arc through 2 to 3
CGContextAddArcToPoint(context, minx, miny, midx, miny, radius);
// Add an arc through 4 to 5
CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius);
// Add an arc through 6 to 7
CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius);
// Add an arc through 8 to 9
CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius);
// Close the path
CGContextClosePath(context);
// Fill & stroke the path
CGContextDrawPath(context, kCGPathFillStroke);
Instead of making your own path out of lines and arcs, you can use
ReplyDelete[UIBezierPath bezierPathWithRoundedRect:cornerRadius:]
or
[UIBezierPath bezierPathWithRoundedRect:byRoundingCorners:cornerRadii:]
(the second one lets you specify which corners are rounded)
Available in iOS 3.2 or later.