@interface NSString(UIStringDrawing)

// Single line, no wrapping. Truncation based on the NSLineBreakMode.

- (CGSize)sizeWithFont:(UIFont*)fontNS_DEPRECATED_IOS(2_0,7_0,"Use -sizeWithAttributes:");

- (CGSize)sizeWithFont:(UIFont*)font forWidth:(CGFloat)width lineBreakMode:(NSLineBreakMode)lineBreakModeNS_DEPRECATED_IOS(2_0,7_0,"Use -boundingRectWithSize:options:attributes:context:");

+ (CGFloat)calulateHeightWithtTitle:(NSString*)title

{

CGFloatheight =;

CGSizelabelSize = [titlesizeWithFont:[UIFont   systemFontOfSize:] constrainedToSize:CGSizeMake(,)];

height = height + labelSize.height;

returnheight;

}

- (CGFloat)tableView:(UITableView*)tableView heightForRowAtIndexPath:(NSIndexPath*)indexPath

{

       return [HomeCell  calulateHeightWithtTitle:self.dataArray[indexPath.row]];

}

// Support for constraint-based layout (auto layout)

// If nonzero, this is used when determining -intrinsicContentSize for multiline labels

@property(nonatomic)CGFloat  preferredMaxLayoutWidthNS_AVAILABLE_IOS(6_0);

@interfaceUIView (UIConstraintBasedLayoutFittingSize)

/* The size fitting most closely to targetSize in which the receiver's subtree can be laid out while optimally satisfying the constraints. If you want the smallest possible size, pass UILayoutFittingCompressedSize; for the largest possible size, pass UILayoutFittingExpandedSize.

Also see the comment for UILayoutPriorityFittingSizeLevel.

*/

- (CGSize)systemLayoutSizeFittingSize:(CGSize)targetSizeNS_AVAILABLE_IOS(6_0);

// Equivalent to sending -systemLayoutSizeFittingSize:withHorizontalFittingPriority:verticalFittingPriority: with UILayoutPriorityFittingSizeLevel for both priorities.

- (NSInteger)numberOfSectionsInTableView:(UITableView*)tableView

{

return1;

}

- (NSInteger)tableView:(UITableView*)tableView numberOfRowsInSection:(NSInteger)section

{

       return [self.dataArraycount];

}

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

{

static NSString *cellIdentifier = @"HomeCell";

HomeCell *cell = [tableView  dequeueReusableCellWithIdentifier:cellIdentifier];

cell.content.text= [self.dataArray  objectAtIndex:indexPath.row];

CGFloat  preMaxWaith =[UIScreen  mainScreen].bounds.size.width-;

[cell.contentset  PreferredMaxLayoutWidth:preMaxWaith];

[cell.contentlayout  IfNeeded];

returncell;

}

-(CGFloat)tableView:(UITableView*)tableView heightForRowAtIndexPath:(NSIndexPath*)indexPath

{

staticHomeCell*cell =nil;

static dispatch_once_  tonceToken;

//只会走一次

dispatch_once(&onceToken, ^{

cell = (HomeCell*)[tableView  dequeueReusableCellWithIdentifier:@"HomeCell"];

});

//calculate

CGFloatheight = [cell  calulateHeightWithtTitle:[self.dataArray objectAtIndex:indexPath.row]desrip:[self.dataArray objectAtIndex:indexPath.row]];

returnheight;

}

HomeCell.m

-(CGFloat)calulateHeightWithtTitle:(NSString*)title desrip:(NSString*)descrip

{

//这里非常重要

CGFloat preMaxWaith =[UIScreen mainScreen].bounds.size.width-;

[self.contentset PreferredMaxLayoutWidth:preMaxWaith];

//[self.titleLabel setText:title];

//这也很重要

[self.content  layoutIfNeeded];

[self.content  setText:descrip];

[self.contentView  layoutIfNeeded];

CGSizesize = [self.contentView  systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];

//加1是关键

returnsize.height+1.0f;

}

self.tableView.estimatedRowHeight=44.0;

self.tableView.rowHeight=UITableViewAutomaticDimension;

// Use the estimatedHeight methods to quickly calcuate guessed values which will allow for fast load times of the table.

// If these methods are implemented, the above -tableView:heightForXXX calls will be deferred until views are ready to be displayed, so more expensive logic can be placed there.

- (CGFloat)tableView:(UITableView*)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath*)indexPathNS_AVAILABLE_IOS(7_0);

 NSDefaultRunLoopMode:    App默认Mode,当没有接收到ScrollView滚动是，主线程通常使用这个Mode

 NSTrackingRunLoopMode:  到接收到ScroolView或其子类的时候，主线程就会切换到这个模式下运行。

 UIInitializationRunLoopMode：当App启动时使用的第一个Mode,当启动完成后不再使用。

 NSRunLoopCommonModes，是一个tag,本质上不是一个Mode,默认                    
 NSDefaultRunLoopMode和NSTrackingRunLoopMode都绑定这个tag。(应用场景：有时候我们需要添加一个NSTimer在RunLoop,在这时需要制定一个Modes，现在的  需求是:我们既要在默认模式下要监听，在滚动模式下也要监听，但只能制定一个模式，这是可以制定这个CommonMode)

 GSEventReceiveRunLoopMode：接受系统内部的Mode,通常做不到。

处理不同事件使用不同的Mode，可以最大限度的把性能的最大化处理不同分类的事件，提高性能。

- (CGFloat)fd_heightForCellWithIdentifier:(NSString*)identifier cacheByIndexPath:(NSIndexPath*)indexPath configuration:(void(^)(id))configuration

{

if(!identifier || !indexPath) {

return0;

}

// Enable auto cache invalidation if you use this "cacheByIndexPath" API.

if(!self.fd_autoCacheInvalidationEnabled) {

self.fd_autoCacheInvalidationEnabled=YES;

}

// Enable precache if you use this "cacheByIndexPath" API.

if(!self.fd_precacheEnabled) {

self.fd_precacheEnabled=YES;

// Manually trigger precache only for the first time.

[selffd_precacheIfNeeded];

}

// Hit the cache

if([self.fd_cellHeightCachehasCachedHeightAtIndexPath:indexPath]) {

[selffd_debugLog:[NSStringstringWithFormat:

@"hit cache - [%@:%@] %@",

@(indexPath.section),

@(indexPath.row),

@([self.fd_cellHeightCachecachedHeightAtIndexPath:indexPath])]];

return[self.fd_cellHeightCachecachedHeightAtIndexPath:indexPath];

}

// Call basic height calculation method.

CGFloatheight = [selffd_heightForCellWithIdentifier:identifierconfiguration:configuration];

[selffd_debugLog:[NSStringstringWithFormat:

@"cached - [%@:%@] %@",

@(indexPath.section),

@(indexPath.row),

@(height)]];

// Cache it

[self.fd_cellHeightCachecacheHeight:heightbyIndexPath:indexPath];

returnheight;

}

// Call basic height calculation method.

CGFloatheight = [selffd_heightForCellWithIdentifier:identifierconfiguration:configuration];

// Cache it

[self.fd_cellHeightCachecacheHeight:heightbyIndexPath:indexPath];

// Enable precache if you use this "cacheByIndexPath" API.

if(!self.fd_precacheEnabled) {

self.fd_precacheEnabled=YES;

// Manually trigger precache only for the first time.

[selffd_precacheIfNeeded];

}

[selfbuildHeightCachesAtIndexPathsIfNeeded:@[indexPath]];

self.sections[indexPath.section][indexPath.row] =@(height);

// Build every section array or row array which is smaller than given index path.

[indexPaths enumerateObjectsUsingBlock:^(NSIndexPath*indexPath,NSUIntegeridx,BOOL*stop) {

NSAssert(indexPath.section>=,@"Expect a positive section rather than '%@'.",@(indexPath.section));

for(NSIntegersection =; section <= indexPath.section; ++section) {

if(section >=self.sections.count) {

self.sections[section] =@[].mutableCopy;

}

}

NSMutableArray*rows =self.sections[indexPath.section];

for(NSIntegerrow =; row <= indexPath.row; ++row) {

if(row >= rows.count) {

rows[row] =@(_FDTemplateLayoutCellHeightCacheAbsentValue);

}

}

}];

dispatch_once(&onceToken, ^{

SELselectors[] = {

@selector(reloadData),

@selector(insertSections:withRowAnimation:),

@selector(deleteSections:withRowAnimation:),

@selector(reloadSections:withRowAnimation:),

@selector(moveSection:toSection:),

@selector(insertRowsAtIndexPaths:withRowAnimation:),

@selector(deleteRowsAtIndexPaths:withRowAnimation:),

@selector(reloadRowsAtIndexPaths:withRowAnimation:),

@selector(moveRowAtIndexPath:toIndexPath:)

};

for(NSUIntegerindex =; index

SELoriginalSelector = selectors[index];

SELswizzledSelector =NSSelectorFromString([@"fd_"stringByAppendingString:NSStringFromSelector(originalSelector)]);

MethodoriginalMethod =class_getInstanceMethod(self, originalSelector);

MethodswizzledMethod =class_getInstanceMethod(self, swizzledSelector);

method_exchangeImplementations(originalMethod, swizzledMethod);

}

});