效果

設定Cell的AutoLayout

這裡要注意的是，添加了一個高度Constraint，這個Constraint是>=50的

SelfSizingCell.m

@interface SelfSizingCell ()<UITextViewDelegate>

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *heightConstraint;

@property (weak, nonatomic) IBOutlet UITextView *textview;

@end
@implementation SelfSizingCell

- (void)awakeFromNib {
    // Initialization code
    self.textview.delegate = self;
    self.textview.scrollEnabled = false;
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

// Configure the view for the selected state
}
-(void)textViewDidChange:(UITextView *)textView{
    CGSize size = [textView sizeThatFits:CGSizeMake(CGRectGetWidth(self.frame), CGFLOAT_MAX)];
    CGFloat height = size.height;
   if (height < 50) {
        self.heightConstraint.constant = 50;
    }else{
       self.heightConstraint.constant = height;
    }
   [self.tableView beginUpdates];
    [self.tableView endUpdates];
 }
@end
 

SelfSizingCell.h

@interface SelfSizingCell : UITableViewCell

@property (weak,nonatomic)UITableView * tableView;

@end

TableviewController

@implementation TableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.tableView registerNib:[UINib nibWithNibName:@"SelfSizingCell" bundle:nil] forCellReuseIdentifier:@"cell"];
    self.tableView.estimatedRowHeight = 50;
    self.tableView.rowHeight = UITableViewAutomaticDimension;
    self.tableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];
 }
#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 1;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    SelfSizingCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell" forIndexPath:indexPath];
    cell.tableView = self.tableView;
    return cell;
}