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萌新！typescript對象里中括號引用應(yīng)該怎么寫才正確？萬分感謝

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SMILET 2019-11-03 09:36:32

constTween={Linear:(t:number,b:number,c:number,d:number)=>(c*t)/d+b,Quad:{easeIn:(t:number,b:number,c:number,d:number)=>c*(t/=d)*t+b,easeOut:(t:number,b:number,c:number,d:number)=>-c*(t/=d)*(t-2)+b,easeInOut:(t:number,b:number,c:number,d:number)=>((t/=d/2){const[name,func]=tween.split('.');if(!func)returnTween.Linear;//Tween[name]這里會報(bào)錯//elementimplicitlyhasananytypebecauseexpressionoftypestringcantbeusedtoindexreturnTween[name][func];};謝過各位大佬

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慕勒3428872

TA貢獻(xiàn)1848條經(jīng)驗(yàn) 獲得超6個(gè)贊

TypeScript目前還不支持字面量類型拆分組合，你可以Tween扁平化，不搞多層。強(qiáng)制轉(zhuǎn)換split出來的類型，這需要你同時(shí)手動維護(hù)兩個(gè)type。或者tween用string類型，對split出來的結(jié)果做額外判斷，確保Tween中有對應(yīng)的域。按2的例子：constTween={Linear:(t:number,b:number,c:number,d:number)=>(c*t)/d+b,Quad:{easeIn:(t:number,b:number,c:number,d:number)=>c*(t/=d)*t+b,easeOut:(t:number,b:number,c:number,d:number)=>-c*(t/=d)*(t-2)+b,easeInOut:(t:number,b:number,c:number,d:number)=>((t/=d/2)<1?(c/2)*t*t+b:(-c/2)*(--t*(t-2)-1)+b),}}typeTweenFunc=|'Linear'|'Quad.easeIn'|'Quad.easeOut'|'Quad.easeInOut';+typeTweenNameFuncPair=+|['Linear']+|['Quad','easeIn']+|['Quad','easeOut']+|['Quad','easeInOut']exportdefault(tween:TweenFunc)=>{+constpair=tween.split('.')asTweenNameFuncPair;+if(!pair[1])returnTween.Linear;+returnTween[pair[0]][pair[1]];};