小编web*_*stx的帖子

为什么我的 store.getState 返回未定义的值！我对 ReactJS 和 Redux 很陌生，这里是我的代码

import {createStore} from \'redux\';\n\nconst initialState = {\nsalary: 1000,\n}\n\nconst reducer = (state=initialState, action) => {\nswitch (action.type) {\n    case "ADD":\n        state = {\n            salary: state.salary+=action.payload,\n        }\n        break;\n\n    default:\n        break;\n}\n}\n\nconst store = createStore(reducer);\n\nstore.subscribe(() => {\nconsole.log(\'Update salary: \', store.getState.salary);\n})\n\nstore.dispatch({\ntype: "ADD",\npayload: 2000,\n});\n

控制台：更新工资：\xe2\x80\x93 undefined

谢谢。

如何在图像下载过程中显示进度条？

我的代码在这里:

 [picView setImageWithURLRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:picURL]] placeholderImage:[UIImage imageNamed:@"placeholder.png"] success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image) {
    NSLog(@"success");


} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {
    NSLog(@"fail");
}    
 ];

先感谢您.

我一直在寻找为Xcode备份用户代码片段,我在下面得到了这个仅用于系统片段!

对于Xcode的自包含应用程序.这是默认代码段的确切文件路径:"/ Applications /Xcode4.3.3.app/Contents/PlugIns/IDECodeSnippetLibrary.ideplugin/C ontents/Resources/SystemCodeSnippets.codesnippets

Xcode 4.6的用户代码片段在哪里？

我尝试以编程方式将数据保存到CloudKit,但是当我从CloudKit获取数据时出现错误

我收到了一个错误

> <CKError 0x608000052060: "Invalid Arguments" (12/2015); server message
> = "Field '___recordID' is not marked queryable"; uuid = 19F1E556-5384-42FD-8F65-9FD8A9C9523D; container ID =
> "iCloud.com.mywebsite.CloudDemo">

这是我的代码.

func saveNewRecordTypeToCloud()  {
        // Prepare the record to save
        var record = CKRecord(recordType: "Members")
        record.setValue("test", forKey: "name")
        record.setValue("test", forKey: "surname")

        // Get iCloud Database
        let cloudContainer = CKContainer.defaultContainer()
        let database = CKContainer.defaultContainer().privateCloudDatabase

        // Save the record to iCloud
        database.saveRecord(record, completionHandler: { (record:CKRecord!, error:NSError! ) in
            if error != nil {
                NSLog(error.localizedDescription)
            } else …