iPhone文本切页代码案例实现

iPhone文本切页代码案例实现是本文要介绍的内容，主要是来学习文本是如何来切页的，本文主要是基于代码实现内容，来看具体实现代码。

//!如果不是HTML，可以把</p>改为n或者rn  
-(NSString *)doPagination:(NSString *)pageContent pageNumber:(NSInteger)number  
                                 fontSize:(NSInteger)size lineHeight:(NSInteger)lheight pageHeight:(NSInteger)pheight  
                                  pageWidth:(NSInteger) pwidth{  
    UIFont *tfont=[UIFont fontWithName:@"Helvetica" size:size];  
    CGFloat singleHeight=[@"中" sizeWithFont:tfont constrainedToSize:CGSizeMake((float)pwidth, 9999.0) 
                          lineBreakMode:UILineBreakModeCharacterWrap ].height;  
    NSInteger maxline_per_page=(int) (pheight/singleHeight);  
    NSArray *paragraphSplit=[pageContent componentsSeparatedByString:@"</p>"];  
    NSString *breakString=@"nn";  
    NSString *contentTrim;  
    NSInteger totalLines=0;  
    NSMutableString *tempString=[NSMutableString string];  
    NSString *leftString;  
    CGSize csize;  
    NSMutableArray *bookPages=[NSMutableArray array];  
    for (NSString *para in paragraphSplit){  
        contentTrim=[para stringByReplacingOccurrencesOfString:@"<p>" withString:breakString];  
        csize=[contentTrim sizeWithFont:tfont constrainedToSize:CGSizeMake((float)pwidth, MAXFLOAT) 
              lineBreakMode:UILineBreakModeCharacterWrap ];  
        totalLines+=(int)(csize.height/singleHeight);  
        leftString=contentTrim;  
        if (totalLines > maxline_per_page){  
            totalLines-=(int)(csize.height/singleHeight);  
            for(int i=0;i<[contentTrim length];i++){  
                NSString *calcString=[contentTrim substringWithRange:NSMakeRange(0, i)];  
                csize=[calcString sizeWithFont:tfont constrainedToSize:CGSizeMake((float)pwidth, MAXFLOAT) 
                                    lineBreakMode:UILineBreakModeCharacterWrap ];  
                totalLinestotalLines=totalLines+(int)(csize.height/singleHeight);  
                if (totalLines>maxline_per_page)  
                {  
                    i--;  
                    if ([calcString length]>0) [tempString appendString:[calcString substringToIndex:([calcString length]-1)]];  
                    if (i>0) leftString=[contentTrim substringFromIndex:i]; else leftString=@"";  
                    [bookPages addObject:[[tempString copy]autorelease]];  
                    totalLines=(int)([leftString sizeWithFont:tfont constrainedToSize:CGSizeMake((float)pwidth, MAXFLOAT) 
                       lineBreakMode:UILineBreakModeCharacterWrap ].height/singleHeight);  
                    [tempString setString:@""];  
                    break;  
                }  
                else totalLinestotalLines=totalLines-(int)(csize.height/singleHeight);  
            }  
        }  
        [tempString appendString:leftString];  
    }  
    [bookPages addObject:[[tempString copy]autorelease]];  
    self.bookContent=[NSArray arrayWithArray:bookPages];  
    return [bookPages objectAtIndex:number];  
} 

小结：iPhone文本切页代码案例实现的内容介绍完了，希望通过本文的学习能对你有所帮助。