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🗣 Wd提问: yii2

🤖 Ai回答:
Yii2 是一个高性能的 PHP 框架，用于快速开发 Web 应用程序。以下是 Yii2 的一些核心概念和使用示例：

1、安装 Yii2

使用 Composer 安装基础应用模板
bash
composer create-project prefer-dist yiisoft/yii2-app-basic basic

安装高级应用模板
bash
composer create-project prefer-dist yiisoft/yii2-app-advanced advanced

2、目录结构

basic/
├── assets/ 资源文件
├── commands/ 控制台命令
├── config/ 配置文件
├── controllers/ 控制器
├── models/ 模型
├── runtime/ 运行时文件
├── tests/ 测试文件
├── vendor/ Composer 依赖
├── views/ 视图文件
├── web/ Web 入口目录
└── yii 控制台入口脚本

3、基本组件

控制器 (Controller)
php
<?php
namespace app\controllers;

use yii\web\Controller;
use yii\web\Response;

class SiteController extends Controller
{
public function actionIndex()
{
return $this-render(&039;index&039;);
}

public function actionHello($name = &039;World&039;)
{
return Hello, 、$name;
}
}

模型 (Model)
php
<?php
namespace app\models;

use yii\base\Model;

class ContactForm extends Model
{
public $name;
public $email;
public $subject;
public $body;

public function rules()
{
return [
[[&039;name&039;, &039;email&039;, &039;subject&039;, &039;body&039;], &039;required&039;],
[&039;email&039;, &039;email&039;],
];
}

public function attributeLabels()
{
return [
&039;name&039; = &039;Your Name&039;,
&039;email&039; = &039;Email Address&039;,
&039;subject&039; = &039;Subject&039;,
&039;body&039; = &039;Message&039;,
];
}
}

视图 (View)
php
<?php
use yii\helpers\Html;
use yii\widgets\ActiveForm;

$this-title = &039;Contact&039;;
?

<h1<?= Html::encode($this-title) ?</h1

<?php $form = ActiveForm::begin(); ?

<?= $form-field($model, &039;name&039;) ?
<?= $form-field($model, &039;email&039;) ?
<?= $form-field($model, &039;subject&039;) ?
<?= $form-field($model, &039;body&039;)-textarea([&039;rows&039; = 6]) ?

<div class=form-group
<?= Html::submitButton(&039;Submit&039;, [&039;class&039; = &039;btn btn-primary&039;]) ?
</div

<?php ActiveForm::end(); ?

4、数据库操作 (ActiveRecord)

定义模型
php
<?php
namespace app\models;

use yii\db\ActiveRecord;

class User extends ActiveRecord
{
public static function tableName()
{
return &039;user&039;;
}

public function rules()
{
return [
[[&039;username&039;, &039;email&039;], &039;required&039;],
[&039;email&039;, &039;email&039;],
[&039;username&039;, &039;unique&039;],
];
}
}

查询数据
php
// 查找单个记录
$user = User::findOne(1);
$user = User::find()-where([&039;username&039; = &039;john&039;])-one();

// 查找多个记录
$users = User::find()-all();
$users = User::find()-where([&039;status&039; = 1])-all();

// 分页查询
$users = User::find()-limit(10)-offset(20)-all();

// 计数
$count = User::find()-count();

保存数据
php
$user = new User();
$user-username = &039;john&039;;
$user-email = &039;john@65.hk&039;;
$user-save();

// 更新
$user = User::findOne(1);
$user-email = &039;newemail@65.hk&039;;
$user-save();

// 删除
$user = User::findOne(1);
$user-delete();

5、路由和 URL

URL 管理
php
// 生成 URL
echo Url::to([&039;site/index&039;]); // /index.php?r=site/index
echo Url::to([&039;post/view&039;, &039;id&039; = 100]); // /index.php?r=post/view&id=100

// 在视图中使用
echo Html::a(&039;Link Text&039;, [&039;site/about&039;]);

URL 规则配置 (config/web.php)
php
&039;urlManager&039; = [
&039;enablePrettyUrl&039; = true,
&039;showScriptName&039; = false,
&039;rules&039; = [
&039;post/<id:\d+&039; = &039;post/view&039;,
&039;posts&039; = &039;post/index&039;,
],
],

6、表单验证和处理

php
public function actionCreate()
{
$model = new Post();

if ($model-load(Yii::$app-request-post()) && $model-save()) {
Yii::$app-session-setFlash(&039;success&039;, &039;Post created successfully!&039;);
return $this-redirect([&039;view&039;, &039;id&039; = $model-id]);
}

return $this-render(&039;create&039;, [
&039;model&039; = $model,
]);
}

7、组件和小部件

使用 GridView
php
use yii\grid\GridView;

echo GridView::widget([
&039;dataProvider&039; = $dataProvider,
&039;columns&039; = [
&039;id&039;,
&039;name&039;,
&039;email&039;,
[
&039;class&039; = &039;yii\grid\ActionColumn&039;,
&039;template&039; = &039;{view} {update} {delete}&039;,
],
],
]);

使用 ActiveForm
php
use yii\widgets\ActiveForm;

$form = ActiveForm::begin([
&039;id&039; = &039;login-form&039;,
&039;options&039; = [&039;class&039; = &039;form-horizontal&039;],
]);

echo $form-field($model, &039;username&039;);
echo $form-field($model, &039;password&039;)-passwordInput();

echo Html::submitButton(&039;Login&039;, [&039;class&039; = &039;btn btn-primary&039;]);

ActiveForm::end();

8、配置文件

主配置文件 (config/web.php)
php
<?php
$params = require __DIR__ 、&039;/params.php&039;;
$db = require __DIR__ 、&039;/db.php&039;;

$config = [
&039;id&039; = &039;basic&039;,
&039;basePath&039; = dirname(__DIR__),
&039;bootstrap&039; = [&039;log&039;],
&039;aliases&039; = [
&039;@bower&039; = &039;@vendor/bower-asset&039;,
&039;@npm&039; = &039;@vendor/npm-asset&039;,
],
&039;components&039; = [
&039;request&039; = [
&039;cookieValidationKey&039; = &039;your-secret-key&039;,
],
&039;cache&039; = [
&039;class&039; = &039;yii\caching\FileCache&039;,
],
&039;user&039; = [
&039;identityClass&039; = &039;app\models\User&039;,
&039;enableAutoLogin&039; = true,
],
&039;db&039; = $db,
&039;urlManager&039; = [
&039;enablePrettyUrl&039; = true,
&039;showScriptName&039; = false,
],
],
&039;params&039; = $params,
];

return $config;

9、常用辅助类

Html 辅助类
php
use yii\helpers\Html;

echo Html::encode($content);
echo Html::a(&039;Click me&039;, [&039;site/index&039;]);
echo Html::img(&039;@web/images/logo.png&039;);
echo Html::tag(&039;div&039;, &039;Content&039;, [&039;class&039; = &039;container&039;]);

ArrayHelper
php
use yii\helpers\ArrayHelper;

// 从数组中获取值
$value = ArrayHelper::getValue($array, &039;key.subkey&039;);

// 将对象数组转换为键值对
$items = ArrayHelper::map($models, &039;id&039;, &039;name&039;);

// 合并数组
$result = ArrayHelper::merge($array1, $array2);

10、错误处理和日志

配置日志
php
&039;log&039; = [
&039;traceLevel&039; = YII_DEBUG ? 3 : 0,
&039;targets&039; = [
[
&039;class&039; = &039;yii\log\FileTarget&039;,
&039;levels&039; = [&039;error&039;, &039;warning&039;],
],
],
],

记录日志
php
Yii::info(&039;This is an info message&039;);
Yii::error(&039;This is an error message&039;);
Yii::warning(&039;This is a warning message&039;);

这是 Yii2 的基础介绍。如果你有具体的问题或需要深入了解某个特定功能，请告诉我！

Ai作答

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