Question

无法找到错误管道的Angular2模块组件

{{obj|json}}

管json找不到。错误的可能原因是什么？

Answer 1

以下是测试代码，它只是起作用：

app.component.ts

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <string>
#include <SQLiteCpp/SQLiteCpp.h>
#include <SQLiteCpp/VariadicBind.h>
// Notice no sqlite3.h huh?
// Well, this is a C++ wrapper for the SQLITE CAPI afterall.

#ifdef SQLITECPP_ENABLE_ASSERT_HANDLER
namespace SQLite
{
/// definition of the assertion handler enabled when SQLITECPP_ENABLE_ASSERT_HANDLER is defined in the project (CMakeList.txt)
void assertion_failed(const char* apFile, const long apLine, const char* apFunc, const char* apExpr, const char* apMsg)
{
// Print a message to the standard error output stream, and abort the program.
std::cerr << apFile << ":" << apLine << ":" << " error: assertion failed (" << apExpr << ") in " << apFunc << "() with message \"" << apMsg << "\"\n";
std::abort();
}
}
#endif

/// Get example path
static inline std::string getExamplePath()
{
std::string filePath(__FILE__);
return filePath.substr(0, filePath.length() - std::string("Client.cpp").length());
}

/// Example Database
static const std::string filename_example_db3 = getExamplePath() + "/example.db3";
/// Image
static const std::string filename_logo_png = getExamplePath() + "/logo.png";


/// Object Oriented Basic example
class Example
{
public:
//Constructor
Example() :
mDb(filename_example_db3),
// User change the db and tables accordingly
mQuery(mDb, "SELECT id,name FROM lookup WHERE name REGEXP :keyword")
// Open a database file in readonly mode
{       
}
virtual ~Example()
{
}

/// List the rows where the "weight" column is greater than the provided aParamValue
void namehaskeyword(const std::string searchfor)
{
std::cout << "Matching results for " << searchfor << "\n";

// Bind the integer value provided to the first parameter of the SQL query
mQuery.bind(1,searchfor); // same as mQuery.bind(1, aParamValue);

 // Loop to execute the query step by step, to get one a row of results at a time
while (mQuery.executeStep())
{
std::cout<<mQuery.getColumn(0) << "\t" << mQuery.getColumn(1) << "\n";
}

// Reset the query to be able to use it again later
mQuery.reset();
}

private:
SQLite::Database    mDb;    ///< Database connection
SQLite::Statement   mQuery; ///< Database prepared SQL query
};

int main()
{
// Using SQLITE_VERSION would require #include <sqlite3.h> which we want to avoid: use SQLite::VERSION if possible.
// std::cout << "SQlite3 version " << SQLITE_VERSION << std::endl;
std::cout << "SQlite3 version " << SQLite::VERSION << " (" << SQLite::getLibVersion() << ")" << std::endl;
std::cout << "SQliteC++ version " << SQLITECPP_VERSION << std::endl;

try
{
// Doing  a regex query.
Example example;
char wannaquit = 'n';
std::string keyword;
// Deliberate unlimited loop. You implement something sensible here.
while (wannaquit != 'y') {
// Demonstrates the way to use the same query with different parameter values
std::cout << "Enter the keyword to search for : ";
std::getline(std::cin, keyword);
example.namehaskeyword(keyword);
}
}
catch (std::exception& e)
{
std::cout << "SQLite exception : " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
return EXIT_SUCCESS;
}

app.component.html

import { Component } from '@angular/core';

@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {

  obj : any = ['test1', 'test2', 'test3'];

}

浏览器输出

[“test1”，“test2”，“test3”]

您可以在此处粘贴代码，以便我们可以检查管道上缺少的确切位置。

您可以在此处查看有关Jsonpipe的更多信息

https://angular.io/api/common/JsonPipe

Answer 2

在我的情况下，它只是重新启动应用程序并且它起作用了。

无法找到给我错误管道的Angular2模块组件

2 个答案: