Harmony OS Next应用“丁斗口算”开发记录(10)

第十节 自动生成题目及答案

本应用题目类型包括加减法、乘除法、方程等，题目生成基于随机数，但也有其他问题需要解决。以加减法为例，主要思路如下：

1. 限定加减法的数值范围，包括10以内、20以内、50以内、100以内：这通过限定生成的随机数的范围实现。
2. 限制加法题目两个加数不能相同：通过判断两个数是否相同，相同则重新生成一个数直到不同为止。
3. 随机的使题目为加法或减法：通过比较两个数的大小实现，如果第一个数大于第二个数，则为减法。如果第一个数小于第二个数，则为加法。
4. 当题目为减法时，不能让结果小于0：第3条可以保证减法的结果不会小于0. 基于以上思路，代码如下： export default class Data_Add{ public N1 :number = 1; public N2 :number = 1; public Symbol:string = '+'; public Rlt :number = 2;

public input : string = ''; public color : Color = Color.Gray;

constructor(max:number) { this.N1 = Math.floor(Math.random()*max/2+1); this.N2 = Math.floor(Math.random()*max/2+1); while(this.N1 == this.N2){ // 保证N1 != N2 this.N2 = Math.floor(Math.random()*max+1); } if( this.N1 > this.N2 ){ this.Symbol = '-'; this.Rlt = this.N1 - this.N2; }else{ this.Rlt = this.N1 + this.N2; } } getDataString(disp:boolean) : string { let rlt : string = this.N1.toString() + this.Symbol + this.N2.toString() + '= ?'; return rlt; } }

以除法为例，主要思路如下：

1. 非小数除法，需保证可以被整除：采用计算乘法方式，即生成两个随机数，将两个数的乘积作为被除数，其中一个随机数作为除数。（注：为提高生成速度，奖第计算量，这里不采用随机生成被除数和除数再判断商是否为整数的方式）
2. 保证被除数的范围和除数的范围：限定两个随机数的范围即可。
3. 保证除数和商不同：判断两个随机数是否相同，相同则重新生成直至不同为止。 代码如下： export default class Data_Div{ public N1 :number = 50; public N2 :number = 50; public Symbol:string = '➗'; public Rlt :number = 1; public input : string = '';

constructor() { while(this.Rlt == this.N2 || this.Rlt<11 || this.N2<11 ){ // 保证N1 N2 符合范围 this.Rlt = Math.floor(Math.random()*99+1); this.N2 = Math.floor(Math.random()*99+1); } this.N1 = this.Rlt * this.N2; } getDataString(disp:boolean) : string { let rlt : string = this.N1.toString() + this.Symbol + this.N2.toString() + '= ?'; if( disp==true ) { //rlt += this.Rlt; } return rlt; } } 用户从首页（index）点击菜单进入题目页面（PageEquation）后，传递一个选择的参数过来（详见上文），题目页面根据传来的参数，调用上文的类，自动生成题目。这里要考虑到平板的面积比手机大，因此平板上生成的题目要比手机上多一些，题目的排列方式（Grid组件）也不同。 代码如下： createEqu(){ console.log('createEqu') switch(this.index){ case 0: // 10以内加减法，生成数据 this.arrDataAdd = []; if(this.deviceType=='tablet') { this.equCount = 20; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr 1fr'; }else{ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_Add(10); this.arrDataAdd.push(bean); } break; case 1: // 20以内加减法，生成数据 this.arrDataAdd = []; if( this.deviceType=='phone' ){ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 20; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_Add(20); this.arrDataAdd.push(bean); } break; case 2: // 50以内加减法，生成数据 this.arrDataAdd = []; if( this.deviceType=='phone' ){ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 20; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_Add(50); this.arrDataAdd.push(bean); } break; case 3: // 九九乘法，生成数据 this.arrDataMul = [];; if( this.deviceType=='phone' ){ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 20; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_Mul(9,1); this.arrDataMul.push(bean);; } break; case 4: // 100以内加减法，生成数据 this.arrDataAdd = []; if( this.deviceType=='phone' ){ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 20; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_Add(100); this.arrDataAdd.push(bean); } break; case 5: // 两位数乘法，生成数据 this.arrDataMul = []; if( this.deviceType=='phone' ){ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 20; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_Mul(29,11); this.arrDataMul.push(bean); this.textInput.push(''); this.inputSelect.push(false); this.rltCorrect.push(false); this.bDispRlt.push(false); } break; case 6: // 四位数除法，生成数据 this.arrDataDiv = []; if( this.deviceType=='phone' ){ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 20; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_Div(); this.arrDataDiv.push(bean); this.textInput.push(''); this.inputSelect.push(false); this.rltCorrect.push(false); this.bDispRlt.push(false); } break; case 7: // 一元一次方程，生成数据 this.arrDataOneEqu = []; if( this.deviceType=='phone' ){ this.equCount = 12; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_OneEqu(39,5); this.arrDataOneEqu.push(bean); this.textInput.push(''); this.inputSelect.push(false); this.rltCorrect.push(false); this.bDispRlt.push(false); } break; case 8: // 四则混合运算 this.arrData4Cal = []; if( this.deviceType=='phone' ){ this.equCount = 12; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; }else{ this.equCount = 16; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_4Cal(); this.arrData4Cal.push(bean); this.textInput.push(''); this.inputSelect.push(false); this.rltCorrect.push(false); this.bDispRlt.push(false); } break; case 9: // 二元一次方程 this.arrDataTwoEqu = []; if( this.deviceType=='phone' ){ this.equCount = 6; this.gridrowtemp_v = '1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr'; }else{ this.equCount = 12; this.gridrowtemp_v = '1fr 1fr 1fr 1fr 1fr 1fr'; this.gridrowtemp_h = '1fr 1fr 1fr'; this.gridcoltemp_v = '1fr 1fr'; this.gridcoltemp_h = '1fr 1fr 1fr 1fr'; } for( let i=0;i<this.equCount;i++ ){ let bean = new Data_TwoEqu(); this.arrDataTwoEqu.push(bean); this.textInput.push(''); this.textInput.push(''); this.inputSelect.push(false); this.inputSelect.push(false); this.rltCorrect.push(false); this.bDispRlt.push(false); } break; } } 至此，完成了题目的生成。