是否有一种简单的方法来比较[String: AnyObject]
swift中的两个词典,因为它不接受==
运算符?
通过比较两个词典,我的意思是检查它们是否具有相同的确切键,并且对于每个键,它们具有相同的值.
我在头文件const double EARTH_RADIUS=6353;
中声明了一个常量,导入到各种其他头文件中,我收到了链接器错误.
Ld /Users/Teguh/Library/Developer/Xcode/DerivedData/BadgerNew-bjopcgcgsjkcvcevflfbvsjwfgnu/Build/Products/Debug-iphonesimulator/BadgerNew.app/BadgerNew normal i386
cd /Users/Teguh/Dropbox/badgers/BadgerNew
setenv MACOSX_DEPLOYMENT_TARGET 10.6
setenv PATH "/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/llvm-g++-4.2 -arch i386 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.3.sdk -L/Users/Teguh/Library/Developer/Xcode/DerivedData/BadgerNew-bjopcgcgsjkcvcevflfbvsjwfgnu/Build/Products/Debug-iphonesimulator -F/Users/Teguh/Library/Developer/Xcode/DerivedData/BadgerNew-bjopcgcgsjkcvcevflfbvsjwfgnu/Build/Products/Debug-iphonesimulator -filelist /Users/Teguh/Library/Developer/Xcode/DerivedData/BadgerNew-bjopcgcgsjkcvcevflfbvsjwfgnu/Build/Intermediates/BadgerNew.build/Debug-iphonesimulator/BadgerNew.build/Objects-normal/i386/BadgerNew.LinkFileList -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -framework CoreLocation -framework UIKit -framework Foundation -framework CoreGraphics -framework CoreData -o /Users/Teguh/Library/Developer/Xcode/DerivedData/BadgerNew-bjopcgcgsjkcvcevflfbvsjwfgnu/Build/Products/Debug-iphonesimulator/BadgerNew.app/BadgerNew
ld: duplicate symbol _EARTH_RADIUS in /Users/Teguh/Library/Developer/Xcode/DerivedData/BadgerNew-bjopcgcgsjkcvcevflfbvsjwfgnu/Build/Intermediates/BadgerNew.build/Debug-iphonesimulator/BadgerNew.build/Objects-normal/i386/NearbyIsiKota.o and /Users/Teguh/Library/Developer/Xcode/DerivedData/BadgerNew-bjopcgcgsjkcvcevflfbvsjwfgnu/Build/Intermediates/BadgerNew.build/Debug-iphonesimulator/BadgerNew.build/Objects-normal/i386/FrontPageofBadger.o for architecture i386
collect2: ld returned 1 exit status
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基本上我希望常量可用于我项目中的所有类.我应该在哪里申报?
我正在尝试使用card_view
.但它一直给出错误.
错误:(13)在'com.google.example.test_app'包中找不到属性''cardCornerRadius'的资源标识符
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
android:background="#610B0B"
tools:context=".MyActivity"
android:id="@+id/myactivity ">
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_gravity="center"
android:background="#fff"
card_view:cardCornerRadius="4dp">
<TextView
android:id="@+id/my_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/next"
android:background="#fff"
android:elevation="5dp" />
</android.support.v7.widget.CardView>
</RelativeLayout>
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我在这做错了什么?
android android-layout android-cardview android-5.0-lollipop
当http.request
有2个事件产生错误时:request.on('error')
和response.on('error')
.
我看不出有什么不同,因为这两个错误都来自Web服务器.
thisError
和之间有什么区别thatError
?
var request = http.request({hostname:"example.com"}, function(response){
response.on('error', function(thisError){
//what's the difference between thisError <<<<<<
});
});
request.on('error', function(thatError){
//and thatError <<<<<
});
Run Code Online (Sandbox Code Playgroud) 我有一个server-app
从客户端接收音频流.我正在尝试使用chai
/ 测试应用程序chai-http
,但它给了我这个错误:
[错误:结束后写]
有什么问题?
码:
var chai = require('chai');
var chaiHttp = require('chai-http');
var server = require('../server-app');
var should = chai.should();
var fs = require('fs');
chai.use(chaiHttp);
describe('server', function() {
it('should work..', function (done){
var req = chai.request(server).post('/speech');
fs.createReadStream('./test.wav').pipe(req);
req.end(function (err,res){
console.log(err);//outputs: [Error: write after end]
done();
});
});
});
Run Code Online (Sandbox Code Playgroud) 我正在尝试实现._read
可读流的功能,在._read
调用时出现问题并且没有数据,文档说我可以push('')
直到更多数据到来,并且只有return false
当流永远不会有更多数据时我才应该。
https://nodejs.org/api/stream.html#stream_readable_read_size_1
但它也说,如果我需要这样做,那么我的设计就会出现严重错误。 https://nodejs.org/api/stream.html#stream_stream_push
但我找不到替代方案。
代码:
var http = require('http');
var https = require('https');
var Readable = require('stream').Readable;
var router = require('express').Router();
var buffer = [];
router.post('/', function(clientRequest, clientResponse) {
var delayedMSStream = new Readable;
delayedMSStream._read = function() {
var a=buffer.shift();
if(typeof a === 'undefined'){
this.push('');
return true;
}
else {
this.push(a);
if(a===null) {
return false;
}
return true;
}
};
//I need to get a url from example.com
https.request({hostname:'example.com'}, function(exampleResponse){ …
Run Code Online (Sandbox Code Playgroud) 我正在尝试将一些音频流式传输到我的服务器,然后将其流式传输到用户指定的服务,用户将提供给我someHostName
,有时可能不支持该类型的请求.
我的问题是,当它发生时,它clientRequest.on('end',..)
永远不会被解雇,我认为这是因为someHostReq
当它someHostName
被"错误" 时,它被管道传输被搞砸了.
我的问题是:
无论如何,clientRequest.on('end',..)
即使流clientRequest
管道出现问题,我仍然可以解雇它吗?
如果不是:如何someHostReq
"立即" 检测到发生了错误?someHostReq.on('error')
除非过了一段时间,否则不会启动.
码:
someHostName = 'somexample.com'
function checkIfPaused(request){//every 1 second check .isPaused
console.log(request.isPaused()+'>>>>');
setTimeout(function(){checkIfPaused(request)},1000);
}
router.post('/', function (clientRequest, clientResponse) {
clientRequest.on('data', function (chunk) {
console.log('pushing data');
});
clientRequest.on('end', function () {//when done streaming audio
console.log('im at the end');
}); //end clientRequest.on('end',)
options = {
hostname: someHostName, method: 'POST', headers: {'Transfer-Encoding': 'chunked'}
};
var someHostReq = http.request(options, function(res){
var data …
Run Code Online (Sandbox Code Playgroud) 我从串口获取字节,表示PIC板上的电压.但是我无法将这些字节(字符串)转换为十进制,因为我收到上面的错误消息.这是函数(事实上,它与tkinter按钮相关联)
def channel8():
ser.write(chr(0xFF))
print "you have select channel8"
x=ser.read(2)
w=int(x, 16)
print w
print "Voltage on channel8 is:" , x
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ValueError:int()的基数为16的无效文字:'\ x0e\xa3'
def channel8():
ser.write(chr(0xFF))
print "you have select channel8"
x=ser.read(2)
z=struct.unpack("h", x)
#w=int(z, 16)
print z
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我得到这个:
通道8上的电压为:(28942,)
你能解释一下我是如何得到这个价值的吗?它不匹配任何东西:D
它可能是简单而愚蠢的东西,但该模块在github页面或npm页面中都没有足够的文档.
有人可以写一个使用.Write函数编写wav文件的代码示例