有非常多时候。UITableViewCell每行的高度是不固定的，须要动态设置。

UITableView有个代理方法，

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return ((CZWeiboFrame*)[self.weiboFrames objectAtIndex:indexPath.row]).rowHeight;

}

有的会想在这里先获取cell。然后过去cell的高度再返回，可是这是不可行的，由于上述方法会在

下述方法之前运行。

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

CZWeiboFrame \*model = self.weiboFrames\[indexPath.row\] ;

static NSString \*identifer = @"weibo";  
CZWeiboCell \*cell = \[tableView dequeueReusableCellWithIdentifier:identifer\];  
if(cell == nil){  
    cell  = \[\[CZWeiboCell alloc \] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifer\];

}  
cell.weiboFrame = model;

return cell;  

}

也就是说在你获取cell之前必须先设置cell的高度。

那么该怎么做呢。那就得在你给cell设置数据时，如今数据模型中计算出高度。

以下是上述代码中CZWeiboViewCell模型的结构

@interface CZWeiboFrame : NSObject

@property (nonatomic,strong) CZWeibo *weibo;
@property (nonatomic,assign,readonly) CGRect iconFrame;
@property (nonatomic,assign,readonly) CGRect textFrame;
@property (nonatomic,assign,readonly) CGRect nameFrame;
@property (nonatomic,assign,readonly) CGRect pictureFrame;
@property (nonatomic,assign,readonly) CGRect vipFrame;
@property (nonatomic,assign,readonly) CGFloat rowHeight;

@end

当中weibo是每行要显示的数据。row height是行高，其余是cell中每一个控件的frame,在weibo的set方法中计算frame

-(void)setWeibo:(CZWeibo *)weibo{
_weibo = weibo;

CGFloat margin = 10;  
CGFloat iconW = 35;  
CGFloat iconH = 35;  
CGFloat iconX = margin;  
CGFloat iconY = margin;  
\_iconFrame = CGRectMake(iconX, iconY, iconW, iconH);

CGFloat nameX = CGRectGetMaxX(\_iconFrame)+margin;  
//依据Labele中文字的内容动态计算大小  
//头文件NSAttributString  
NSDictionary \*attr = @{NSFontAttributeName:nameFont};  
CGSize nameSize = \[self sizeWithText:\_weibo.name size:CGSizeMake(MAXFLOAT, MAXFLOAT) font:nameFont\];  
CGFloat nameW = nameSize.width;  
CGFloat nameH = nameSize.height;  
CGFloat nameY = iconY + (iconH - nameH)/2;

_nameFrame = CGRectMake(nameX, nameY, nameW, nameH);

CGFloat vipW = 10;  
CGFloat vipH = 10;  
CGFloat vipX = CGRectGetMaxX(\_nameFrame)+margin;  
CGFloat vipY = iconY +(iconH - vipH)/2;  
\_vipFrame = CGRectMake(vipX, vipY, vipW, vipH);

CGFloat textX = iconX;  
CGFloat textY = CGRectGetMaxY(\_iconFrame)+margin;  
CGSize s = CGSizeMake(\[\[UIScreen mainScreen\] bounds\].size.width - margin\*2, MAXFLOAT);  
CGSize textSize = \[self sizeWithText:weibo.text size:s font:textFont\];

\_textFrame = CGRectMake(textX, textY, textSize.width, textSize.height);

CGFloat picW = 200;  
CGFloat picH = 200;  
CGFloat picX = iconX;  
CGFloat picY = CGRectGetMaxY(\_textFrame)+margin;  
\_pictureFrame = CGRectMake(picX, picY, picW, picH)  ;

\_rowHeight = 0;  
if(self.weibo.picture){  
    \_rowHeight = CGRectGetMaxY(\_pictureFrame)+margin;  
}else{  
    \_rowHeight = CGRectGetMaxY(\_textFrame)+margin;  
}  

}

///获取字符串的size
-(CGSize) sizeWithText:(NSString *) text size:(CGSize) size font:(UIFont *)font{
NSDictionary *dict = @{NSFontAttributeName:font };
CGSize sz = [text boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:dict context:nil].size;
return sz;
}

然后我们就能给每一行设置高度了

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return ((CZWeiboFrame*)[self.weiboFrames objectAtIndex:indexPath.row]).rowHeight;

}