无限级

 protected function getSubs($categorys,$pid=0,$level=1){
    $subs=array();
    foreach($categorys as $item){
        if($item['pid']==$pid){
            $item['level']=$level;
            $subs[]=$item;
            $subs=array_merge($subs,$this->getSubs($categorys,$item['id'],$level+1));
        }
    }
    return $subs;
}

三级联动

 <?= $form->field($region,'province')->label('省')->dropDownList($region->getCityList(0),
[
    'prompt'=>'--请选择省--',
    'onchange'=>'
        $(".field-region-city").hide();
        $(".field-region-area").hide();
        $.post("'.yii::$app->urlManager->createUrl('resume/site').'&level=1&parent_id="+$(this).val(),function(data){
        $(".field-region-city").show();
            $("#region-city").html(data);
        });',
]) ?>

 <?= $form->field($region, 'city')->label('市')->dropDownList($region->getCityList($region->province),
[
    'prompt'=>'--请选择市--',
    'onchange'=>'
        $(".field-region-area").show();
        $.post("'.yii::$app->urlManager->createUrl('resume/site').'&level=2&parent_id="+$(this).val(),function(data){
            $("#region-area").html(data);
        });',
]) ?>
 <?= $form->field($region, 'area')->label('区')->dropDownList($region->getCityList($region->city),['prompt'=>'--请选择区--',]) ?>

图片处理

   yii\imagine\Image;
  //生成一张裁剪模式100 x 100 的缩略图
  Image::thumbnail('../web/1.jpg', 100 , 100)->save(Yii::getAlias('../web/2.jpg'),['quality' => 100]);
  裁剪从坐标0,0 裁剪一张300 x 20 的图片,并保存为1-crop.jpg
  Image::crop('../web/1.jpg', 300 , 20,[400,300])->save(Yii::getAlias('../web/1-crop.jpg'), ['quality' => 100]);
  给图片加文字
  $textOpt = ['color'=>'f00','size'=>'40','angle'=>5];
  $fontFile = Yii::getAlias('../web/myweb/fonts/ywyb.ttf');
  Image::text(Yii::getAlias('../web/1.jpg'), '呜呼啦嘿', $fontFile, [300, 450], $textOpt)->save(Yii::getAlias('../web/text-1.jpg'), ['quality' => 100]);

验证码

controller
public function actions(){
    return [
        'error' => [
            'class' => 'yii\web\ErrorAction',
        ],
        'captcha' => [
                'class' => 'yii\captcha\CaptchaAction',
                'fixedVerifyCode' => YII_ENV_TEST ? 'testme' : null,
                'backColor'=>0x000000,//背景颜色
                'maxLength' => 6, //最大显示个数
                'minLength' => 5,//最少显示个数
                'padding' => 5,//间距
                'height'=>40,//高度
                'width' => 130,  //宽度
                'foreColor'=>0xffffff,     //字体颜色
                'offset'=>4,        //设置字符偏移量 有效果
                //'controller'=>'login',        //拥有这个动作的controller
        ],
    ];
}

   model

   public $verifyCode;
   public function rules(){
    return [
        ['verifyCode', 'captcha']
    ];
}
public function attributeLabels(){
    return [
        'verifyCode' => 'Verification Code',
    ];
}
 
view

use yii\captcha\Captcha;
?= $form->field($model, 'verifyCode')->textInput(['class'=>'dl_textinp'])->label('') ?>
                    <?=Captcha::widget(['name'=>'captchaimg','captchaAction'=>'site/captcha',
            'imageOptions'=>['id'=>'captchaimg', 'title'=>'换一个', 'alt'=>'换一个', 'style'=>'cursor:pointer;margin-left:25px;'],'template'=>'{image}']);?>