在 nativescript 应用程序中显示 sqlite 数据库数据时出现问题

Question

我的应用程序有一个记分牌页面，它应该从 sqlite 数据库中获取数据并将其显示在 ListView 的 NavigatingTo 页面上，但它没有按预期执行。

显示结果的xml页面：

<Page xmlns="http://schemas.nativescript.org/tns.xsd" loaded="pageLoaded" navigatingTo="onNavigatingTo">

<ActionBar title="Scoreboard">
  <NavigationButton text="Back" android.systemIcon="ic_menu_back" tap="homeTap"/>
</ActionBar>

<StackLayout orientation="vertical">        
    <Label text="Your Performance Sheet"></Label>
    <ListView items= "{{results}}" > 
        <ListView.itemTemplate>
            <Label text="{{testname}}"/>
            <Label text="{{score}}"/>
            <Label text="{{percent}}"/>
        </ListView.itemTemplate>
    </ListView>
</StackLayout>

</Page>

计分板视图模型：

var Observable = require("data/observable").Observable;
var ObservableArray = require("data/observable-array").ObservableArray;
var Sqlite = require("nativescript-sqlite");

function scoreViewModel (database) {

var viewModel = new Observable();

viewModel.results = new ObservableArray([]);

viewModel.select = function () {
    this.results = new ObservableArray([]);
    database.all("SELECT * FROM scores").then(rows => {

    for (var row in rows) {         
        this.results.push(rows[row]); 
    }
    }, error => {
        console.log("SELECT ERROR", error);
    })
}   
viewModel.select();

return viewModel;       
}

exports.scoreViewModel = scoreViewModel;

我正在从分数 table 中选择所有数据并推送到已经绑定到视图的 viewModel.results 数组。

scoreboard.js :

var observable = require("data/observable");
var scoreViewModel = require("./scoreboard-view-model").scoreViewModel;
var page;
var Sqlite = require("nativescript-sqlite");

exports.onNavigatingTo = function (args) {
page = args.object;


(new Sqlite("scoreboard.db")).then(db => {
    db.execSQL("CREATE TABLE IF NOT EXISTS scores (id INTEGER PRIMARY KEY AUTOINCREMENT, testname TEXT, score TEXT, percent TEXT)")
    .then(id => {
        page.bindingContext = scoreViewModel(db);           
    }, error => {
        console.log(error)
    });
}, error => {
    console.log(error);
});
}

谁能帮我把数据显示在列表视图中。

Answer 1

我通过编辑 scoreboard-view-model.js 文件使它工作，正好在 viewModel.Select 函数中：

viewModel.select = function () {
    //the line below was changed to this...
    //testname, score, and percent are column names in the scores table
    database.all("SELECT testname, score, percent FROM scores").then(rows => {

    for (var row in rows) {
        //the line below was changed too...     
        viewModel.results.push({testname: rows[row][0], score: rows[row][1], percent: rows[row][2]});
    }, error => {
        console.log("SELECT ERROR", error);
    })
}

完成。它现在按预期工作。感谢 TJ Vantoll 提供的帮助。非常感谢。

在 nativescript 应用程序中显示 sqlite 数据库数据时出现问题

Having issues displaying sqlite db data in nativescript application

javascript

sqlite

nativescript