JS控制文本框内键盘上下左右键的焦点

avaScript键盘上下左右控制文本框焦点的方法有很多,这里简单说两种方法:

方法一:

创建一个table的dom元素,包含5行4列的文本框

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">  
    <html>  
      <head>      
        <title>keyboard control 1</title>      
        <style>  
            tr.highlight{background:#08246B;color:white;}  
        </style>  
      </head>    
      <body>  
    <table border="1" width="70%" id="ice">  
        <tr>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
        </tr>  
        <tr>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
        </tr>  
        <tr>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
        </tr>  
        <tr>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
        </tr>  
        <tr>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
            <td><input type='text'></td>  
        </tr>  
    </table>  
    <script language="javascript">  
    <!--  
    //定义初始化行列  
    var currentLine=0;  // 目前的行号  
    var currentCol=0;  
     var objtab=document.all.ice;  
     var colums = objtab.rows[4].cells.length;  
    var objrow=objtab.rows[0].getElementsByTagName("INPUT");  
     objrow[0].select();  
    document.body.onkeydown=function(e){  
      e=window.event||e;  
      switch(e.keyCode){  
        case 37: //左键  
          currentCol--;  
          changeItem(e);  
          break;  
        case 38: //向上键  
          currentLine--;  
          changeItem(e);  
          break;  
        case 39: //右键  
          currentCol++;  
          changeItem(e);  
          break;  
        case 40: //向下键  
          currentLine++;  
          changeItem(e);  
          break;  
        default:  
          break;  
      }  
    }  
    //方向键调用  
    function changeItem(e){  
      if(document.all){//如果是IE  
        var it=document.getElementById("ice").children[0];   //获取table表单元素  
      }else{//其他浏览器  
        var it=document.getElementById("ice");  
      }  
         
     if(e.keyCode==37||e.keyCode==39){  
        if(currentLine<0){//如果行小于0  
            currentLine=it.rows.length-1;  
          }  
          if(currentLine==it.rows.length){  
           currentLine=0;  
          }  
          var objtab=document.all.ice;  
          var objrow=objtab.rows[currentLine].getElementsByTagName("INPUT");  
            
           
          if(currentCol<0){  
             
            if(e.keyCode==37){  
                currentLine--;  
                if(currentLine<0){//如果行小于0  
                    currentLine=it.rows.length-1;  
                 }  
                objrow=objtab.rows[currentLine].getElementsByTagName("INPUT");    
            }  
            currentCol=objrow.length-1;  
          }  
            
          if(currentCol>=objrow.length){  
            if(e.keyCode==39){  
                currentLine++;  
                 if(currentLine==it.rows.length){  
                  currentLine=0;  
                  }   
                  objrow=objtab.rows[currentLine].getElementsByTagName("INPUT");      
            }  
            currentCol=0;    
              
          }    
     }else{  
        if(currentLine<0){//如果行小于0  
            currentLine=it.rows.length-1;  
            currentCol--;  
            if(currentCol<0){  
                currentCol=colums-1;  
            }  
          }  
          if(currentLine==it.rows.length){  
             currentLine=0;  
             currentCol++;  
             if(currentCol>=colums){  
                currentCol=0;  
             }  
          }  
          var objtab=document.all.ice;  
          var objrow=objtab.rows[currentLine].getElementsByTagName("INPUT");  
          while(e.keyCode==40&&objrow[currentCol]==undefined){  
            currentLine++;  
            objrow=objtab.rows[currentLine].getElementsByTagName("INPUT");        
          }  
          while(e.keyCode==38&&objrow[currentCol]==undefined){  
            currentLine--;        
            objrow=objtab.rows[currentLine].getElementsByTagName("INPUT");    
          }  
            
     }    
      objrow[currentCol].select();  
    }  
    //-->  
    </script>  
      </body>  
    </html>

基本思路是获取表单的行列数,监听键盘操作,通过DOM操作表格的行列来选取表格内的文本框。

方法二:

这个方法试用于动态创建多个文本框的情况,将所有的文本框划分为行列数组,为每个input设置id值,监听键盘操作设置,设置onmouseup方法获取当前鼠标位置,然后游当前位置确认数组的下一个相应文本框,将其选中。这里以简单粗糙的方式呈现基本思路

[html] view plain copy

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">  
    <html>  
      <head>      
        <title>keyborad control 2</title>      
        <style>  
            tr.highlight{background:#08246B;color:white;}  
        </style>  
      </head>    
      <body>  
    <table border="1" width="70%" id="ice">  
        <tr>  
            <td><input id="td11" onmouseup=getMouse(1,1) ></td>  
            <td><input id="td12" onmouseup=getMouse(1,2)></td>  
            <td><input id="td13" onmouseup=getMouse(1,3)></td>  
            <td><input id="td14" onmouseup=getMouse(1,4)></td>  
        </tr>  
        <tr>  
            <td><input id="td21" onmouseup=getMouse(2,1)></td>  
            <td><input id="td22" onmouseup=getMouse(2,2)></td>  
            <td><input id="td23" onmouseup=getMouse(2,3)></td>  
            <td><input id="td24" onmouseup=getMouse(2,4)></td>  
        </tr>  
        <tr>  
            <td><input id="td31" onmouseup=getMouse(3,1)></td>  
            <td><input id="td32" onmouseup=getMouse(3,2)></td>  
            <td><input id="td33" onmouseup=getMouse(3,3)></td>  
            <td><input id="td34" onmouseup=getMouse(3,4)></td>  
        </tr>  
    </table>  
    <script language="javascript">  
    <!--  
        var mouseInfo={};      //存放鼠标的当前位置  
        var moveArray=new Array();     //存放文本框数组  
        for(var i=1;i<4;i++){  
            moveArray[i]=new Array();  
            for(var j=1;j<5;j++){  
                moveArray[i][j]="td"+i+j;  
            }  
        }  
          
        document.body.onkeydown=function(e){  //监听鼠标操作  
          e=window.event||e;  
          switch(e.keyCode){  
            case 37: //左键  
              moveLeft();  
              break;  
            case 38: //向上键  
              moveUp();  
              break;  
            case 39: //右键  
              moveRight();  
              break;  
            case 40: //向下键  
              moveDown();  
              break;  
            default:  
              break;  
          }  
        }  
          
          
    function getMouse(l,k){//鼠标所在位置  
        mouseInfo["row"]=l;  
        mouseInfo["col"]=k;  
    }  
    function moveLeft(){    
        var row=mouseInfo["row"];  
        var col=mouseInfo["col"];  
          
        var key=moveArray[row][col-1];  
        if(document.getElementById(key)!=undefined)  
        {  
            var textFiled=document.getElementById(key);  
            textFiled.focus(false, 1000);  
            textFiled.select();  
            mouseInfo["col"]=col-1;  
        }  
      
    }  
    function moveRight(){  
        var row=mouseInfo["row"];  
        var col=mouseInfo["col"];  
          
        var key=moveArray[row][col+1];  
        if(document.getElementById(key)!=undefined)  
        {  
            var textFiled=document.getElementById(key);  
            textFiled.focus(false, 1000);  
            textFiled.select();  
            mouseInfo["col"]=col+1;  
        }  
    }  
    function moveUp(){  
        var row=mouseInfo["row"];  
        var col=mouseInfo["col"];  
          
        var key=moveArray[row-1][col];  
        if(document.getElementById(key)!=undefined)  
        {  
            var textFiled=document.getElementById(key);  
            textFiled.focus(false, 1000);  
            textFiled.select();  
            mouseInfo["row"]=row-1;  
        }     
    }  
    function moveDown(){  
        var row=mouseInfo["row"];  
        var col=mouseInfo["col"];  
          
        var key=moveArray[row+1][col];  
        if(document.getElementById(key)!=undefined)  
        {  
            var textFiled=document.getElementById(key);  
            textFiled.focus(false, 1000);  
            textFiled.select();  
            mouseInfo["row"]=row+1;  
        }     
    }  
          
    //-->  
    </script>  
      </body>  
    </html>

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