问SpriteKit：“String”不能转换为“DictionaryIndex<String，SKTexture>”

EN

import SpriteKit

class Player {
    let states: Dictionary<String, SKTexture> = [
        "standing": SKTexture(imageNamed: "standing"),
        "right1": SKTexture(imageNamed: "right1"),
        "right2": SKTexture(imageNamed: "right2"),
        "right3": SKTexture(imageNamed: "right3"),
        "left1": SKTexture(imageNamed: "left1"),
        "left2": SKTexture(imageNamed: "left2"),
        "left3": SKTexture(imageNamed: "left3")
    ]

    let LEFT: UInt32 = 1 << 0
    let FRONT: UInt32 = 1 << 1
    let RIGHT: UInt32 = 1 << 2

    var node: SKSpriteNode!
    var status: UInt32!

    let delay = SKAction.waitForDuration(NSTimeInterval(0.1))

    var runLeft: SKAction!
    var runRight: SKAction!

    init(){
        for state in states {
            state.1.filteringMode = .Nearest
        }

        node = SKSpriteNode(texture: states["standing"])

        node.physicsBody = SKPhysicsBody(rectangleOfSize: node.size)
        node.physicsBody.dynamic = false

        status = FRONT

        runLeft = SKAction.animateWithTextures([states["left1"], states["left2"], states["left1"], states["left3"]]!, timePerFrame: 0.1)
        runRight = SKAction.animateWithTextures([states["right1"], states["right2"], states["right1"], states["right3"]]!, timePerFrame: 0.1)
    }
}