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问题:
I would like to customize both the background and the border color of a grouped-style UITableView.
I was able to customize the background color by using the following:
tableView.contentView.backgroundColor = [UIColor greenColor];
But the border color is still something I don\'t know how to change.
How do I customize these two aspects of the grouped-style table view?
回答1:
UPDATE: In iPhone OS 3.0 and later UITableViewCell
now has a backgroundColor
property that makes this really easy (especially in combination with the [UIColor colorWithPatternImage:]
initializer). But I\'ll leave the 2.0 version of the answer here for anyone that needs it…
It\'s harder than it really should be. Here\'s how I did this when I had to do it:
You need to set the UITableViewCell\'s backgroundView property to a custom UIView that draws the border and background itself in the appropriate colors. This view needs to be able to draw the borders in 4 different modes, rounded on the top for the first cell in a section, rounded on the bottom for the last cell in a section, no rounded corners for cells in the middle of a section, and rounded on all 4 corners for sections that contain one cell.
Unfortunately I couldn\'t figure out how to have this mode set automatically, so I had to set it in the UITableViewDataSource\'s -cellForRowAtIndexPath method.
It\'s a real PITA but I\'ve confirmed with Apple engineers that this is currently the only way.
Update Here\'s the code for that custom bg view. There\'s a drawing bug that makes the rounded corners look a little funny, but we moved to a different design and scrapped the custom backgrounds before I had a chance to fix it. Still this will probably be very helpful for you:
//
// CustomCellBackgroundView.h
//
// Created by Mike Akers on 11/21/08.
// Copyright 2008 __MyCompanyName__. All rights reserved.
//
#import <UIKit/UIKit.h>
typedef enum {
CustomCellBackgroundViewPositionTop,
CustomCellBackgroundViewPositionMiddle,
CustomCellBackgroundViewPositionBottom,
CustomCellBackgroundViewPositionSingle
} CustomCellBackgroundViewPosition;
@interface CustomCellBackgroundView : UIView {
UIColor *borderColor;
UIColor *fillColor;
CustomCellBackgroundViewPosition position;
}
@property(nonatomic, retain) UIColor *borderColor, *fillColor;
@property(nonatomic) CustomCellBackgroundViewPosition position;
@end
//
// CustomCellBackgroundView.m
//
// Created by Mike Akers on 11/21/08.
// Copyright 2008 __MyCompanyName__. All rights reserved.
//
#import \"CustomCellBackgroundView.h\"
static void addRoundedRectToPath(CGContextRef context, CGRect rect,
float ovalWidth,float ovalHeight);
@implementation CustomCellBackgroundView
@synthesize borderColor, fillColor, position;
- (BOOL) isOpaque {
return NO;
}
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// Initialization code
}
return self;
}
- (void)drawRect:(CGRect)rect {
// Drawing code
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(c, [fillColor CGColor]);
CGContextSetStrokeColorWithColor(c, [borderColor CGColor]);
if (position == CustomCellBackgroundViewPositionTop) {
CGContextFillRect(c, CGRectMake(0.0f, rect.size.height - 10.0f, rect.size.width, 10.0f));
CGContextBeginPath(c);
CGContextMoveToPoint(c, 0.0f, rect.size.height - 10.0f);
CGContextAddLineToPoint(c, 0.0f, rect.size.height);
CGContextAddLineToPoint(c, rect.size.width, rect.size.height);
CGContextAddLineToPoint(c, rect.size.width, rect.size.height - 10.0f);
CGContextStrokePath(c);
CGContextClipToRect(c, CGRectMake(0.0f, 0.0f, rect.size.width, rect.size.height - 10.0f));
} else if (position == CustomCellBackgroundViewPositionBottom) {
CGContextFillRect(c, CGRectMake(0.0f, 0.0f, rect.size.width, 10.0f));
CGContextBeginPath(c);
CGContextMoveToPoint(c, 0.0f, 10.0f);
CGContextAddLineToPoint(c, 0.0f, 0.0f);
CGContextStrokePath(c);
CGContextBeginPath(c);
CGContextMoveToPoint(c, rect.size.width, 0.0f);
CGContextAddLineToPoint(c, rect.size.width, 10.0f);
CGContextStrokePath(c);
CGContextClipToRect(c, CGRectMake(0.0f, 10.0f, rect.size.width, rect.size.height));
} else if (position == CustomCellBackgroundViewPositionMiddle) {
CGContextFillRect(c, rect);
CGContextBeginPath(c);
CGContextMoveToPoint(c, 0.0f, 0.0f);
CGContextAddLineToPoint(c, 0.0f, rect.size.height);
CGContextAddLineToPoint(c, rect.size.width, rect.size.height);
CGContextAddLineToPoint(c, rect.size.width, 0.0f);
CGContextStrokePath(c);
return; // no need to bother drawing rounded corners, so we return
}
// At this point the clip rect is set to only draw the appropriate
// corners, so we fill and stroke a rounded rect taking the entire rect
CGContextBeginPath(c);
addRoundedRectToPath(c, rect, 10.0f, 10.0f);
CGContextFillPath(c);
CGContextSetLineWidth(c, 1);
CGContextBeginPath(c);
addRoundedRectToPath(c, rect, 10.0f, 10.0f);
CGContextStrokePath(c);
}
- (void)dealloc {
[borderColor release];
[fillColor release];
[super dealloc];
}
@end
static void addRoundedRectToPath(CGContextRef context, CGRect rect,
float ovalWidth,float ovalHeight)
{
float fw, fh;
if (ovalWidth == 0 || ovalHeight == 0) {// 1
CGContextAddRect(context, rect);
return;
}
CGContextSaveGState(context);// 2
CGContextTranslateCTM (context, CGRectGetMinX(rect),// 3
CGRectGetMinY(rect));
CGContextScaleCTM (context, ovalWidth, ovalHeight);// 4
fw = CGRectGetWidth (rect) / ovalWidth;// 5
fh = CGRectGetHeight (rect) / ovalHeight;// 6
CGContextMoveToPoint(context, fw, fh/2); // 7
CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1);// 8
CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1);// 9
CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1);// 10
CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // 11
CGContextClosePath(context);// 12
CGContextRestoreGState(context);// 13
}
回答2:
I know the answers are relating to changing grouped table cells, but in case someone is wanting to also change the tableview\'s background color:
Not only do you need to set:
tableview.backgroundColor = color;
You also need to change or get rid of the background view:
tableview.backgroundView = nil;
回答3:
First of all thanks for this code. I have made some drawing changes in this function to remove corner problem of drawing.
-(void)drawRect:(CGRect)rect
{
// Drawing code
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(c, [fillColor CGColor]);
CGContextSetStrokeColorWithColor(c, [borderColor CGColor]);
CGContextSetLineWidth(c, 2);
if (position == CustomCellBackgroundViewPositionTop) {
CGFloat minx = CGRectGetMinX(rect) , midx = CGRectGetMidX(rect), maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny + 1;
maxx = maxx - 1;
maxy = maxy ;
CGContextMoveToPoint(c, minx, maxy);
CGContextAddArcToPoint(c, minx, miny, midx, miny, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, miny, maxx, maxy, ROUND_SIZE);
CGContextAddLineToPoint(c, maxx, maxy);
// Close the path
CGContextClosePath(c);
// Fill & stroke the path
CGContextDrawPath(c, kCGPathFillStroke);
return;
} else if (position == CustomCellBackgroundViewPositionBottom) {
CGFloat minx = CGRectGetMinX(rect) , midx = CGRectGetMidX(rect), maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny ;
maxx = maxx - 1;
maxy = maxy - 1;
CGContextMoveToPoint(c, minx, miny);
CGContextAddArcToPoint(c, minx, maxy, midx, maxy, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, maxy, maxx, miny, ROUND_SIZE);
CGContextAddLineToPoint(c, maxx, miny);
// Close the path
CGContextClosePath(c);
// Fill & stroke the path
CGContextDrawPath(c, kCGPathFillStroke);
return;
} else if (position == CustomCellBackgroundViewPositionMiddle) {
CGFloat minx = CGRectGetMinX(rect) , maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny ;
maxx = maxx - 1;
maxy = maxy ;
CGContextMoveToPoint(c, minx, miny);
CGContextAddLineToPoint(c, maxx, miny);
CGContextAddLineToPoint(c, maxx, maxy);
CGContextAddLineToPoint(c, minx, maxy);
CGContextClosePath(c);
// Fill & stroke the path
CGContextDrawPath(c, kCGPathFillStroke);
return;
}
}
回答4:
Thank you for the code, it\'s just what I was looking for. I have also added the following code to Vimal\'s code, to implement the case of a CustomCellBackgroundViewPositionSingle cell. (All four corners are rounded.)
else if (position == CustomCellBackgroundViewPositionSingle)
{
CGFloat minx = CGRectGetMinX(rect) , midx = CGRectGetMidX(rect), maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , midy = CGRectGetMidY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny + 1;
maxx = maxx - 1;
maxy = maxy - 1;
CGContextMoveToPoint(c, minx, midy);
CGContextAddArcToPoint(c, minx, miny, midx, miny, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, miny, maxx, midy, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, maxy, midx, maxy, ROUND_SIZE);
CGContextAddArcToPoint(c, minx, maxy, minx, midy, ROUND_SIZE);
// Close the path
CGContextClosePath(c);
// Fill & stroke the path
CGContextDrawPath(c, kCGPathFillStroke);
return;
}
回答5:
One thing I ran into with the above CustomCellBackgroundView code from Mike Akers which might be useful to others:
cell.backgroundView
doesn\'t get automatically redrawn when cells are reused, and changes to the backgroundView\'s position var don\'t affect reused cells. That means long tables will have incorrectly drawn cell.backgroundViews
given their positions.
To fix this without having to create a new backgroundView every time a row is displayed, call [cell.backgroundView setNeedsDisplay]
at the end of your -[UITableViewController tableView:cellForRowAtIndexPath:]
. Or for a more reusable solution, override CustomCellBackgroundView\'s position setter to include a [self setNeedsDisplay]
.
回答6:
Thanks for this super helpful post. In case anyone out there (like me!) wants to just have a completely empty cell background in lieu of customizing it through images/text/other content in IB and cannot figure out how the hell to get rid of the dumb border/padding/background even though you set it to clear in IB... here\'s the code I used that did the trick!
- (UITableViewCell *) tableView: (UITableView *) tableView cellForRowAtIndexPath: (NSIndexPath *) indexPath {
static NSString *cellId = @\"cellId\";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: cellId];
if (cell == nil) {
[[NSBundle mainBundle] loadNibNamed:@\"EditTableViewCell\" owner:self options:nil];
cell = cellIBOutlet;
self.cellIBOutlet = nil;
}
cell.backgroundView = [[[UIView alloc] initWithFrame: CGRectZero] autorelease];
[cell.backgroundView setNeedsDisplay];
... any other cell customizations ...
return cell;
}
Hopefully that\'ll help someone else! Seems to work like a charm.
回答7:
Much thanks to all who posted their code. This is very useful.
I derived a similar solution to change the highlight color for grouped table view cells. Basically the UITableViewCell\'s selectedBackgroundView (not the backgroundView). Which even on iPhone OS 3.0 still needs this PITA solution, as far as I can tell...
The code below has the changes for rendering the highlight with a gradient instead of one solid color. Also the border rendering is removed. Enjoy.
//
// CSCustomCellBackgroundView.h
//
#import <UIKit/UIKit.h>
typedef enum
{
CustomCellBackgroundViewPositionTop,
CustomCellBackgroundViewPositionMiddle,
CustomCellBackgroundViewPositionBottom,
CustomCellBackgroundViewPositionSingle,
CustomCellBackgroundViewPositionPlain
} CustomCellBackgroundViewPosition;
@interface CSCustomCellBackgroundView : UIView
{
CustomCellBackgroundViewPosition position;
CGGradientRef gradient;
}
@property(nonatomic) CustomCellBackgroundViewPosition position;
@end
//
// CSCustomCellBackgroundView.m
//
#import \"CSCustomCellBackgroundView.h\"
#define ROUND_SIZE 10
static void addRoundedRectToPath(CGContextRef context, CGRect rect,
float ovalWidth,float ovalHeight);
@implementation CSCustomCellBackgroundView
@synthesize position;
- (BOOL) isOpaque
{
return NO;
}
- (id)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame])
{
// Initialization code
const float* topCol = CGColorGetComponents([[UIColor redColor] CGColor]);
const float* bottomCol = CGColorGetComponents([[UIColor blueColor] CGColor]);
CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();
/*
CGFloat colors[] =
{
5.0 / 255.0, 140.0 / 255.0, 245.0 / 255.0, 1.00,
1.0 / 255.0, 93.0 / 255.0, 230.0 / 255.0, 1.00,
};*/
CGFloat colors[]=
{
topCol[0], topCol[1], topCol[2], topCol[3],
bottomCol[0], bottomCol[1], bottomCol[2], bottomCol[3]
};
gradient = CGGradientCreateWithColorComponents(rgb, colors, NULL, sizeof(colors)/(sizeof(colors[0])*4));
CGColorSpaceRelease(rgb);
}
return self;
}
-(void)drawRect:(CGRect)rect
{
// Drawing code
CGContextRef c = UIGraphicsGetCurrentContext();
if (position == CustomCellBackgroundViewPositionTop)
{
CGFloat minx = CGRectGetMinX(rect) , midx = CGRectGetMidX(rect), maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny + 1;
maxx = maxx - 1;
maxy = maxy ;
CGContextMoveToPoint(c, minx, maxy);
CGContextAddArcToPoint(c, minx, miny, midx, miny, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, miny, maxx, maxy, ROUND_SIZE);
CGContextAddLineToPoint(c, maxx, maxy);
// Close the path
CGContextClosePath(c);
CGContextSaveGState(c);
CGContextClip(c);
CGContextDrawLinearGradient(c, gradient, CGPointMake(minx,miny), CGPointMake(minx,maxy), kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
CGContextRestoreGState(c);
return;
}
else if (position == CustomCellBackgroundViewPositionBottom)
{
CGFloat minx = CGRectGetMinX(rect) , midx = CGRectGetMidX(rect), maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny + 1;
maxx = maxx - 1;
maxy = maxy - 1;
CGContextMoveToPoint(c, minx, miny);
CGContextAddArcToPoint(c, minx, maxy, midx, maxy, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, maxy, maxx, miny, ROUND_SIZE);
CGContextAddLineToPoint(c, maxx, miny);
// Close the path
CGContextClosePath(c);
CGContextSaveGState(c);
CGContextClip(c);
CGContextDrawLinearGradient(c, gradient, CGPointMake(minx,miny), CGPointMake(minx,maxy), kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
CGContextRestoreGState(c);
return;
}
else if (position == CustomCellBackgroundViewPositionMiddle)
{
CGFloat minx = CGRectGetMinX(rect) , maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny + 1;
maxx = maxx - 1;
maxy = maxy ;
CGContextMoveToPoint(c, minx, miny);
CGContextAddLineToPoint(c, maxx, miny);
CGContextAddLineToPoint(c, maxx, maxy);
CGContextAddLineToPoint(c, minx, maxy);
// Close the path
CGContextClosePath(c);
CGContextSaveGState(c);
CGContextClip(c);
CGContextDrawLinearGradient(c, gradient, CGPointMake(minx,miny), CGPointMake(minx,maxy), kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
CGContextRestoreGState(c);
return;
}
else if (position == CustomCellBackgroundViewPositionSingle)
{
CGFloat minx = CGRectGetMinX(rect) , midx = CGRectGetMidX(rect), maxx = CGRectGetMaxX(rect) ;
CGFloat miny = CGRectGetMinY(rect) , midy = CGRectGetMidY(rect) , maxy = CGRectGetMaxY(rect) ;
minx = minx + 1;
miny = miny + 1;
maxx = maxx - 1;
maxy = maxy - 1;
CGContextMoveToPoint(c, minx, midy);
CGContextAddArcToPoint(c, minx, miny, midx, miny, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, miny, maxx, midy, ROUND_SIZE);
CGContextAddArcToPoint(c, maxx, maxy, midx, maxy, ROUND_SIZE);
CGContextAddArcToPoint(c, minx, maxy, minx, midy, ROUND_SIZE);
// Close the path
CGContextClosePath(c);
CGContextSaveGState(c);
CGContextClip(c);
CGContextDrawLinearGradient(c, gradient, CGPointMake(minx,miny), CGPointMake(minx,maxy), kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
CGContextRestoreGState(c);
return;
}
else if (position == CustomCellBackgroundViewPositionPlain) {
CGFloat minx = CGRectGetMinX(rect);
CGFloat miny = CGRectGetMinY(rect), maxy = CGRectGetMaxY(rect) ;
CGContextDrawLinearGradient(c, gradient, CGPointMake(minx,miny), CGPointMake(minx,maxy), kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
return;
}
}
- (void)dealloc
{
CGGradientRelease(gradient);
[super dealloc];
}
- (void) setPosition:(CustomCellBackgroundViewPosition)inPosition
{
if(position != inPosition)
{
position = inPosition;
[self setNeedsDisplay];
}
}
@end
static void addRoundedRectToPath(CGContextRef context, CGRect rect,
float ovalWidth,float ovalHeight)
{
float fw, fh;
if (ovalWidth == 0 || ovalHeight == 0) {// 1
CGContextAddRect(context, rect);
return;
}
CGContextSaveGState(context);// 2
CGContextTranslateCTM (context, CGRectGetMinX(rect),// 3
CGRectGetMinY(rect));
CGContextScaleCTM (context, ovalWidth, ovalHeight);// 4
fw = CGRectGetWidth (rect) / ovalWidth;// 5
fh = CGRectGetHeight (rect) / ovalHeight;// 6
CGContextMoveToPoint(context, fw, fh/2); // 7
CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1);// 8
CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1);// 9
CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1);// 10
CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // 11
CGContextClosePath(context);// 12
CGContextRestoreGState(context);// 13
}
回答8:
You can customize the border color by setting
tableView.separatorColor
回答9:
To change the table view border color:
In.h:
#import <QuartzCore/QuartzCore.h>
In .m:
tableView.layer.masksToBounds=YES;
tableView.layer.borderWidth = 1.0f;
tableView.layer.borderColor = [UIColor whiteColor].CGColor;
回答10:
This task can be easily done using PrettyKit by adding about 5 lines of code. If you use nib
files or storyboard
, also do not forget to apply this little hack . When you use this approach, you should subclass your cell from PrettyTableViewCell
:
#import <PrettyKit/PrettyKit.h>
@class RRSearchHistoryItem;
@interface RRSearchHistoryCell : PrettyTableViewCell
This is example of my cellForRowAtIndexPath
:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = @\"RRSearchHistoryCell\";
RRSearchHistoryCell *cell = (RRSearchHistoryCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if ( cell == nil ) {
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@\"RRSearchHistoryCell\" owner:self options:nil];
cell = topLevelObjects[0];
cell.gradientStartColor = RGB(0xffffff);
cell.gradientEndColor = RGB(0xf3f3f3);
}
RRSearchHistoryItem *item = _historyTableData[indexPath.row];
[cell setHistoryItem:item];
[cell prepareForTableView:tableView indexPath:indexPath];
return cell;
}
回答11:
I have been having problems with this and tried lots of combinations of things as I noticed that for some cells it worked fine but not for others.
Strangely I found out that it is possible to set the cell.backgroundColor to lightGrayColor and all works perfectly - but blueColor caused me problems of not updating the outside edges.
Unless it is really important to use green - perhaps you might want to try this. It might be that this is a feature to get people to use only grey colours when indicating a cell is selected.