【iOS】—— 仿写知乎日报第三周总结
知乎日报
这周有点小摆，不过还是基本完成了知乎日报的仿写任务，这周的主要重心在完成评论界面和FMDB数据库存储的使用以及离线加载。
评论
在写评论界面的时候，首先是关于评论文字高度的问题，刚开始使用的方法用法不对，所以一直无法将label的高度获取下来，导致刚开始写的评论高度都是固定的，再后来仔细学习了
sizeThatFits:
这个方法的用法，发现这个方法必须在一个label的基础上才能用，然后我把这个函数在tableView的事件函数上使用，会发生奇奇怪怪的复用问题，因此我把这个方法放在了tableView初始化之前：
UILabel *label = [[UILabel alloc] init];
label.text = self.longDictionary[@"comments"][i][@"content"];
label.numberOfLines = 0;
label.textAlignment = NSTextAlignmentLeft;
label.font = [UIFont systemFontOfSize:18];
//sizeThatFits:方法的使用
[self.longLabelHeightArray addObject:[NSString stringWithFormat:@"%lf", [label sizeThatFits:CGSizeMake(0.89 * SIZE_WIDTH - 50, CGFLOAT_MAX)].height + 35]];
对于正常的没有回复的评论按照这样写就可以解决问题，但是遇到有回复的就需要判断回复的评论是小于两行还是大于两行，如果小于两行直接放在主label的下面，大于两行则将其只显示两行，然后下面显示展开button，对于是否有button在tableView事件函数里进行判定，如果大于两行有button，其余情况也有button，但是颜色为clear，并且只有当button颜色不是clear时候才能触发事件函数。
//展开button事件函数
- (void)pressExpand:(UIButton *)button {
if (button.tintColor != [UIColor clearColor]) {
if ([self.allBoolArray[button.tag] isEqualToString: @"0"]) {
if ([self.longDictionary[@"comments"] count] == 0) {
self.shortLabelHeightArray[button.tag] = [NSString stringWithFormat:@"%lf", [self.shortBoolArray[button.tag] doubleValue] + [self.shortLabelHeightArray[button.tag] doubleValue]];
} else {
if (button.tag < [self.longDictionary[@"comments"] count]) {
self.longLabelHeightArray[button.tag] = [NSString stringWithFormat:@"%lf", [self.longBoolArray[button.tag] doubleValue] + [self.longLabelHeightArray[button.tag] doubleValue]];
} else {
self.shortLabelHeightArray[button.tag - [_longDictionary[@"comments"] count]] = [NSString stringWithFormat:@"%lf", [self.shortBoolArray[button.tag - [self.longDictionary[@"comments"] count]] doubleValue] + [self.shortLabelHeightArray[button.tag - [self.longDictionary[@"comments"] count]] doubleValue]];
}
}
self.allBoolArray[button.tag] = @"1";
} else {
if ([self.longDictionary[@"comments"] count] == 0) {
self.shortLabelHeightArray[button.tag] = [NSString stringWithFormat:@"%lf", -[self.shortBoolArray[button.tag] doubleValue] + [self.shortLabelHeightArray[button.tag] doubleValue]];
} else {
if (button.tag < [self.longDictionary[@"comments"] count]) {
self.longLabelHeightArray[button.tag] = [NSString stringWithFormat:@"%lf", -[self.longBoolArray[button.tag] doubleValue] + [self.longLabelHeightArray[button.tag] doubleValue]];
} else {
self.shortLabelHeightArray[button.tag - [self.longDictionary[@"comments"] count]] = [NSString stringWithFormat:@"%lf", -[self.shortBoolArray[button.tag - [self.longDictionary[@"comments"] count]] doubleValue] + [self.shortLabelHeightArray[button.tag - [self.longDictionary[@"comments"] count]] doubleValue]];
}
}
self.allBoolArray[button.tag] = @"0";
}
[self.tableView reloadData];
}
}
FMDB存储
关于FMDB存储类似于c语言的文件操作，但是用法比文件操作简单很多，主要操作分为FMDatabase数据库的初始化和FMDatabase的增删改查，理解抽象但是操作比较简单易懂。
可以看大佬博客
FMDB的基础用法
这是我的关于收藏和点赞数据库的基本操作：
//FMDB初始化
- (void)databaseInit {
NSString *collectionDoc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *collectionFileName = [collectionDoc stringByAppendingPathComponent:@"collectionData.sqlite"];
self.collectionDatabase = [FMDatabase databaseWithPath:collectionFileName];
if ([self.collectionDatabase open]) {
BOOL result = [self.collectionDatabase executeUpdate:@"CREATE TABLE IF NOT EXISTS collectionData (mainLabel text NOT NULL, imageURL text NOT NULL, id text NOT NULL);"];
if (result) {
NSLog(@"创表成功");
} else {
NSLog(@"创表失败");
}
}
NSString *goodDoc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *goodFileName = [goodDoc stringByAppendingPathComponent:@"goodData.sqlite"];
self.goodDatabase = [FMDatabase databaseWithPath:goodFileName];
if ([self.goodDatabase open]) {
BOOL result = [self.goodDatabase executeUpdate:@"CREATE TABLE IF NOT EXISTS goodData (id text NOT NULL);"];
if (result) {
NSLog(@"创表成功");
} else {
NSLog(@"创表失败");
}
}
}
// 查询数据
- (void)queryData {
int good = 0, collect = 0;
if ([self.collectionDatabase open]) {
// 1.执行查询语句
FMResultSet *collectionResultSet = [self.collectionDatabase executeQuery:@"SELECT * FROM collectionData"];
// 2.遍历结果
while ([collectionResultSet next]) {
NSString *id = [collectionResultSet stringForColumn:@"id"];
int idInt = [id intValue];
int nowInt = [_nowID intValue];
//NSLog(@"`````````%@ %@ %@",id,[collectionResultSet stringForColumn:@"mainLabel"],[collectionResultSet stringForColumn:@"imageURL"]);
if (nowInt == idInt) {
self.wkWebView.collectButton.tag = 104;
[self.wkWebView.collectButton setImage:[UIImage imageNamed:@"shoucang3.png"] forState:UIControlStateNormal];
collect = 1;
}
}
[self.collectionDatabase close];
}
if ([self.goodDatabase open]) {
// 1.执行查询语句
FMResultSet *goodResultSet = [self.goodDatabase executeQuery:@"SELECT * FROM goodData"];
// 2.遍历结果
while ([goodResultSet next]) {
NSString *nowId = [NSString stringWithFormat:@"%@", [goodResultSet objectForColumn:@"id"]];
int idInt = [nowId intValue];
int nowInt = [_nowID intValue];
if (idInt == nowInt) {
self.wkWebView.goodButton.tag = 103;
[self.wkWebView.goodButton setImage:[UIImage imageNamed:@"dianzan2.png"] forState:UIControlStateNormal];
int goodNum = [self.wkWebView.goodLabel.text intValue];
goodNum++;
self.wkWebView.goodLabel.text = [NSString stringWithFormat:@"%d", goodNum];
//break;
good = 1;
}
}
[self.goodDatabase close];
}
if (good == 0) {
self.wkWebView.goodButton.tag = 3;
[self.wkWebView.goodButton setImage:[UIImage imageNamed:@"dianzan.png"] forState:UIControlStateNormal];
int goodNum = [self.wkWebView.goodLabel.text intValue];
self.wkWebView.goodLabel.text = [NSString stringWithFormat:@"%d", goodNum];
}
if (collect == 0) {
self.wkWebView.collectButton.tag = 4;
[self.wkWebView.collectButton setImage:[UIImage imageNamed:@"shoucang.png"] forState:UIControlStateNormal];
}
}
//插入数据
- (void)insertGoodData:(NSString *)string {
if ([self.goodDatabase open]) {
NSLog(@"%@",string);
BOOL result = [self.goodDatabase executeUpdate:@"INSERT INTO goodData (id) VALUES (?);", string];
if (!result) {
NSLog(@"增加数据失败");
} else {
NSLog(@"增加数据成功");
}
[self.goodDatabase close];
}
}
//插入数据
- (void)insertCollectionData:(NSString *)mainLabel and:(NSString *)imageURL and:(NSString *)nowId{
if ([self.collectionDatabase open]) {
BOOL result = [self.collectionDatabase executeUpdate:@"INSERT INTO collectionData (mainLabel, imageURL, id) VALUES (?, ?, ?);", mainLabel, imageURL, nowId];
if (!result) {
NSLog(@"增加数据失败");
} else {
NSLog(@"增加数据成功");
}
[self.collectionDatabase close];
}
}
// 删除数据
- (void)deleteGoodData:(NSString *)nowId {
if ([self.goodDatabase open]) {
NSString *sql = @"delete from goodData WHERE id = ?";
BOOL result = [self.goodDatabase executeUpdate:sql, nowId];
if (!result) {
NSLog(@"数据删除失败");
} else {
NSLog(@"数据删除成功");
}
[self.goodDatabase close];
}
}
// 删除数据
- (void)deleteCollectionData:(NSString *)nowId {
if ([self.collectionDatabase open]) {
NSString *sql = @"delete from collectionData WHERE id = ?";
BOOL result = [self.collectionDatabase executeUpdate:sql, nowId];
if (!result) {
NSLog(@"数据删除失败");
} else {
NSLog(@"数据删除成功");
}
[self.collectionDatabase close];
}
}
关于离线加载
离线加载的主要应用其实也是关于FMDB，我的操作是在有网络的情况下每一次启动应用首先清空数据库，然后将此时首页请求到的数据存储在数据库里，待到下一次没有网络的时候app启动，将存储在数据库里的东西赋值上去，但是要注意一些原本该有的赋值以及点击函数的数组或字典为空，将这些操作终止掉，保证点击任何地方不会报错即可，我的方式是运用一个int类型的值，在请求成功和请求失败的情况下分别是不同的值，以此来判断是否应该触发点击事件以及刷新等函数。
- (void)firstNetworkRequest {
[[MainManager sharedManage] NetWorkWithData:^(MainModel * _Nonnull mainViewModel) {
NSLog(@"请求成功");
self->_firstDictionary = [[NSMutableDictionary alloc] init];
self->_firstDictionary = [mainViewModel toDictionary];
NSLog(@"%@",self->_firstDictionary);
[self->_allArray addObject:[mainViewModel toDictionary]];
// 异步执行任务创建方法
dispatch_async(dispatch_get_main_queue(), ^{
[self beforeNetworkRequest];
[self deleteCacheData];
for (int i = 0; i < 5; i++) {
[self insertCacheData:self->_firstDictionary[@"top_stories"][i][@"title"] and:self->_firstDictionary[@"top_stories"][i][@"image"] and:self->_firstDictionary[@"top_stories"][i][@"hint"]];
}
for (int i = 0; i < 6; i++) {
[self insertCacheData:self->_firstDictionary[@"stories"][i][@"title"] and:self->_firstDictionary[@"stories"][i][@"images"][0] and:self->_firstDictionary[@"stories"][i][@"hint"]];
}
});
} error:^(NSError * _Nonnull error) {
dispatch_async(dispatch_get_main_queue(), ^{
//[self.mainView addNavigationControllerView];
[self queryData];
self.mainView.firstDictionary = self->_firstDictionary;
NSLog(@"------%@",self.mainView.firstDictionary);
self.mainView.section = 2;
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"通知" message:@"网络出现问题" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *sure = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:nil];
[alertController addAction:sure];
[self presentViewController:alertController animated:YES completion:nil];
[self.mainView viewInit];
});
NSLog(@"请求失败");
}];
}
//cell点进去
- (void)getClickNumber:(int)clickNumber {
if (self.mainView.section == 4) { //判断是否有网
_viewController = [[WKWebViewController alloc] init];
_viewController.delegate = self;
if (_allArray[0][@"top_stories"] == nil) {
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
dictionary = _allArray[0];
_allArray[0] = _allArray[1];
_allArray[1] = dictionary;
}
_viewController.clickNumber = clickNumber;
_viewController.allArray = _allArray;
_viewController.beforeDay = _beforeDay;
_viewController.pushViewController = 0;
[self.navigationController pushViewController:_viewController animated:YES];
}
}
图片虚化效果
参考学长博客 iOS——简单实现图片渐变