前言
相信对于iOS开发者们来说，在开发过程中，经常用UITableView，一定会遇到数据为空的情况，这时需要在空页面上放一个图片和一行文字提示数据为空，下面整理了两种方法来实现这个功能。
第一个是继承UITableView，在新类中集成图片和文字
#import <UIKit/UIKit.h>
#import "Const.h"
@interface WFEmptyTableView : UITableView
@property (nonatomic, assign) BOOL showEmptyTipView; // 是否显示背景提示文字
@property (nonatomic, assign) NSInteger vOffset;
@property (nonatomic, copy) NSString *tipString; // 提示文字
@property (nonatomic, copy) NSString *tipImageName; // 提示图片
@end
具体实现
#import "WFEmptyTableView.h"
@implementation WFEmptyTableView {
UIView *_customBackView;
UIImageView *_tipImageView;
UILabel *_label;
CGRect _imageFrame;
CGRect _labelFrame;
double _scale;
}
- (WFEmptyTableView *)initWithFrame:(CGRect)frame style:(UITableViewStyle)style {
self = [super initWithFrame:frame style:style];
if (self) {
[self setupViews];
}
return self;
}
- (void)setupViews {
_customBackView = [[UIView alloc] initWithFrame:self.frame];
_customBackView.backgroundColor = [UIColor yellowColor];
_tipImageView = [[UIImageView alloc] initWithFrame:CGRectMake((kScreenWidth-200/2)/2, self.frame.size.height/3, 200/2, 200/2)];
[_customBackView addSubview:_tipImageView];
_imageFrame = _tipImageView.frame;
_label = [[UILabel alloc] initWithFrame:CGRectMake(0, CGRectGetMaxY(_tipImageView.frame), kScreenWidth, 100)];
_label.backgroundColor = [UIColor clearColor];
_label.textAlignment = NSTextAlignmentCenter;
_label.textColor = [UIColor lightGrayColor];
_label.font = [UIFont systemFontOfSize:16];
_label.lineBreakMode = NSLineBreakByCharWrapping;
_label.numberOfLines = 0;
[_customBackView addSubview:_label];
_labelFrame = _label.frame;
}
- (void)setShowEmptyTipView:(BOOL)showEmptyTipView {
_showEmptyTipView = showEmptyTipView;
if (showEmptyTipView) {
[self addSubview:_customBackView];
} else {
[_customBackView removeFromSuperview];
}
}
- (void)setTipString:(NSString *)tipString {
_tipString = tipString;
NSMutableAttributedString * attributedString1 = [[NSMutableAttributedString alloc] initWithString:tipString];
NSMutableParagraphStyle * paragraphStyle1 = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle1 setLineSpacing:15];
[paragraphStyle1 setAlignment:NSTextAlignmentCenter];
[attributedString1 addAttribute:NSParagraphStyleAttributeName value:paragraphStyle1 range:NSMakeRange(0, [tipString length])];
[_label setAttributedText:attributedString1];
[self resetFrame];
}
- (void)setTipImageName:(NSString *)tipImageName {
_scale = 1;
UIImage *image = [UIImage imageNamed:tipImageName];
_scale = image.size.height*1.0 / image.size.width;
_tipImageView.image = image;
if (isnan(_scale)) {
_scale = 1;
}
[self resetFrame];
}
- (void)setVOffset:(NSInteger)vOffset {
_label.frame = CGRectMake(CGRectGetMinX(_label.frame), CGRectGetMinY(_label.frame)+vOffset, CGRectGetWidth(_label.frame), CGRectGetHeight(_label.frame));
_tipImageView.frame = CGRectMake(CGRectGetMinX(_tipImageView.frame), CGRectGetMinY(_tipImageView.frame)+vOffset, CGRectGetWidth(_tipImageView.frame), CGRectGetHeight(_tipImageView.frame));
}
- (void)resetFrame {
_tipImageView.frame = CGRectMake(0, CGRectGetMinY(_tipImageView.frame), 150, 150 * _scale);
_tipImageView.center = CGPointMake(kScreenWidth / 2.0, _tipImageView.center.y);
_label.frame = CGRectMake(CGRectGetMinX(_label.frame), CGRectGetMaxY(_tipImageView.frame), CGRectGetWidth(_label.frame), CGRectGetHeight(_label.frame));
}
@end
