开发中的问题集合

1.Terminating app due to uncaught exception 'NSUnknownKeyException', reason

网上搜了一大堆，都是说XIB的关联问题，我把xib文件删除了连接，重新连了一下，还是报错。后来发现是我的代码问题。

NSMutableDictionary *dict = (NSMutableDictionary *)array.lastObject;
[dict setValue:textString forKey:@"limit"];

array.lastObject不是可变字典，这里我把它强转了，导致
[dict setValue:textString forKey:@"limit"];报错。
用 NSDictionary 就可以了。

2. 重新安装xcode cocoapods出现

          Unable to download data from https://gems.ruby-china.org/ - bad response Not Found 404 (https://gems.ruby-china.org/specs.4.8.gz)```， 即执行``` sudo gem install cocoapods

出现的错
执行 sudo -i, 进入到 root 去执行该命令

sudo -i

在去执行

sudo gem install cocoapods

结果为

Successfully installed cocoapods-1.6.1
Parsing documentation for cocoapods-1.6.1
Done installing documentation for cocoapods after 2 seconds
1 gem installed

退出root, 重新打开一个窗口，执行 pod --version，查看版本，但是现在又报错了

Ignoring executable-hooks-1.4.2 because its extensions are not built.  Try: gem pristine executable-hooks --version 1.4.2
Ignoring gem-wrappers-1.3.2 because its extensions are not built.  Try: gem pristine gem-wrappers --version 1.3.2
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/rubygems.rb:241:in `bin_path': can't find gem cocoapods (>= 0.a) (Gem::GemNotFoundException)
    from /usr/local/bin/pod:22:in `<main>'

接着删除了gem ,清除所有包旧版本，保留最新版

gem cleanup

结果为

Cleaning up installed gems...
Clean Up Complete

查看gem版本

gem update

结果为

2.6.14

接着执行

gem update

又报错了

Updating installed gems
ERROR:  While executing gem ... (Gem::RemoteFetcher::FetchError)
    bad response Not Found 404 (https://gems.ruby-china.org/specs.4.8.gz)

解决办法：
先后执行下面2行代码：

sudo gem sources -r https://rubygems.org
结果为：
Password:
source https://rubygems.org not present in cache

sudo gem sources -a http://rubygems.org
结果为：
https://rubygems.org is recommended for security over http://rubygems.org

Do you want to add this insecure source? [yn]  y
http://rubygems.org added to sources

就可以正常安装了
执行

sudo gem install cocoapods

结果为：

………………(代表还有很多命令)
Parsing documentation for molinillo-0.6.6
Installing ri documentation for molinillo-0.6.6
Parsing documentation for atomos-0.1.3
Installing ri documentation for atomos-0.1.3
Parsing documentation for nanaimo-0.2.6
Installing ri documentation for nanaimo-0.2.6
Parsing documentation for xcodeproj-1.8.1
Installing ri documentation for xcodeproj-1.8.1
Parsing documentation for fourflusher-2.2.0
Installing ri documentation for fourflusher-2.2.0
Parsing documentation for ruby-macho-1.4.0
Installing ri documentation for ruby-macho-1.4.0
Parsing documentation for cocoapods-1.6.1
Installing ri documentation for cocoapods-1.6.1
Done installing documentation for cocoapods-core, cocoapods-downloader, cocoapods-trunk, molinillo, atomos, nanaimo, xcodeproj, fourflusher, ruby-macho, cocoapods after 9 seconds
WARNING:  Unable to pull data from 'https://gems.ruby-china.org/': bad response Not Found 404 (https://gems.ruby-china.org/specs.4.8.gz)
10 gems installed

3. 更新cocoaPods，执行命令 sudo gem update --system .出现了错误： ERROR: While executing gem ... (Gem::RemoteFetcher::FetchError)； bad response Not Found 404 (https://gems.ruby-china.org/specs.4.8.gz)

原来是cocoapods更新了，本来是1.6.0，执行了下面命令更新pod之后，版本变为1.7.0.beta.3

sudo gem install -n /usr/local/bin cocoapods --pre

再去执行一些命令就好了

4. ld: framework not found Pods__________ clang: error: linker command failed with exit code 1 (use -v to see invocation)

出现这个问题，把Build Settings ---->的 Other Linker Flags里面的所有库都删除了，就只剩下了第二个图里面的

2291553674047_.pic_hd.jpg

2301553675241_.pic_hd.jpg

然后把Build Phases 的Linker Binary With Libraries删除不存在（显示为颜色灰白）的库
在command +shift +k, 清空一下，重新运行，即可了

5. ld: library not found for -lstdc++.6.0.9 , clang: error: linker command failed with exit code 1 (use -v to see invocation)

多数情况下是文件路径配置问题
在Building Phases下面的 Link Binary With Libraries把这个库show In Finder, 发现并不是在工程里路径下，重新把它拖到了工程目录里面，就好了。

2331553839647_.pic.jpg

2341553840027_.pic.jpg

6. Could not insert new outlet connection, could not find any information for the class named DemoViewController

把DemoViewController.h 和 DemoViewController.m 先show In finder, 拷贝出来，在工程里面删除，重新添加就好了

7. cell复用问题导致页面上展示的数组顺序错乱

在实例化cell的时候, 把cell的赋值放在了实例化的方法里,, 出现了cell复用的问题,每次cell为空的时候,就会创建一个, 重新赋值,就会出现问题

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
      LoanPartTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"loanPartCell"];
      if (cell == nil) {
            cell = [[LoanPartTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"loanPartCell"];
            cell.selectionStyle = UITableViewCellSelectionStyleNone;
            cell.model = self.sectionOneNewArray[indexPath.row];
      }
     return cell;
}

把cell的赋值拿到外面去实现, 或者直接采用tableview注册cell的方法就可以避免这个问题

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
      LoanPartTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"loanPartCell"];
      if (cell == nil) {
            cell = [[LoanPartTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"loanPartCell"];
            cell.selectionStyle = UITableViewCellSelectionStyleNone;
      }
      cell.model = self.sectionOneNewArray[indexPath.row];
     return cell;
}

8. tableview页面滑动时卡顿, 来回切换视图,卡顿时, 优化方法

把图片放在异步线程中加载, 采用缓存的形式, SDWebImage

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{

        if (!([model.iconUrlStr isKindOfClass:[NSNull class]])) {
            NSString *urlStr = [QiNiuDownLoadUrl stringByAppendingString:model.iconUrlStr];
            urlStr =  [urlStr stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
           [self.iconIMV sd_setImageWithURL:[NSURL URLWithString:urlStr] placeholderImage:[UIImage imageNamed:@"home_laba"]]; //小喇叭图标获取
        }
});