JavaFx：如何在GridPane中比较动态创建的TextFields的值？

我正在使用JavaFx开发一个应用程序,其中我在GridPane中创建动态TextFields,并且有一个Button最初被禁用,如下所示：

所以我想要的是如果第1列TextFields值小于第3列TextFields值,则按钮应该像这样启用：

但是,如果第3列TextField值中的任何值变得小于同一行的第1列TextField值,则应禁用按钮并以红色显示特定的TextField边框,并将鼠标悬停在该字段上时应显示一些警告：

我正在创建像这样的TextField：

public static GridPane table(int rows){
            GridPane table = new GridPane();

            for(int i=0; i<rows; i++){
            TextField textField1 = new JFXTextField();
            textField1.setAlignment(Pos.CENTER);
            TextField textField2 = new JFXTextField();
            textField2.setAlignment(Pos.CENTER);
            TextField textField3 = new JFXTextField();
            textField3.setAlignment(Pos.CENTER);

            //add them to the GridPane
            table.add(textField1, 0, i+1);
            table.add(textField2, 1, i+1);
            table.add(textField3, 2, i+1);
         }
        return table;
    }

之后,我正在创建另一个方法来返回特定行和列的表中的组件,如下所示：

public static Node getComponent (int row, int column, GridPane table) {
         for (Node component : table.getChildren()) { // loop through every node in the table
             if(GridPane.getRowIndex(component) == row && 
                             GridPane.getColumnIndex(component) == column) {
                 return component;
             }
         }

         return null;
     }

我尝试这样做,但它不起作用(这里我将值转换为字符串并仅比较检查)：

private boolean isTextEqual(GridPane table, Button button){

        for(Node node : table.getChildren()){ 
            if(node instanceof TextField){
                for(int i=1 ; i<=ComboBox().getValue(); i++){
                    String str = ((TextField)DynamicGridpanes.getComponent (i, 0, table)).getText();
                    ((TextField)DynamicGridpanes.getComponent (i, 2, table)).textProperty().addListener((obs, old, newV)->{ 
                    if(newV.toString()==str){
                        button.setDisable(false);
                    }
                    else{
                        button.setDisable(true);
                    }
                 });
                    }
                }
            }

        return true;
    }

解决方法:

实际上,做你想做的事情并不容易,因为你需要重构代码(代码并不是要做这样的高级要求,但它对你的基本要求很好).但是,你可以这样做：

首先,使用无效TextField的最后一行索引定义要更新的全局变量(从此处您将得出结论,这将一次更改一个无效TextField的边框颜色)：

public static int textFieldIndex = -1;

现在,在已经有getComponent(int row,int column,GridPane表)的方法的帮助下,创建另一个静态方法来检查所有TextFields是否一次都有有效值：

/**
* This method to check at run time with every change in any TextField 
* if the corresponding TextField has a valid value(i.e contains number and
* the first TextField value is less than the second)
* @param table
* @param numRows
*/
private static boolean hasValidValue(GridPane table, int numRows){
   // cycle through every row in the table
   // and compare every two TextFields
   for(int i=0; i<numRows; i++){
      try{ // try because user may enters a non-number input (to avoid crash)
         // the first TextField is always at column index 0 , the second at column index 3
         if(Integer.parseInt(((TextField)(getComponent (i, 0, table))).getText())>
            Integer.parseInt(((TextField)(getComponent (i, 3, table))).getText())){
            // before returning false
            textFieldIndex = i; // update at which row the TextField is less
            return false;
          }
       }catch(NumberFormatException e){ // if it contains invalid input(non-digit)
            return false;
       }
   }
   return true; 
}

现在,您需要在validateTable()方法中使用上述方法并进行一些调整：

// pass the comboBox.getValue() to the third parameter
private void validateTable(GridPane table, Button button, int numRows) {

   for(Node textField : table.getChildren()){ 
      if(textField instanceof TextField){
         ((TextField)textField).textProperty().addListener((obs, old, newV)->{
           // first of all remove the red border from the invalid TextField (if any)
          // we know that via textFieldIndex which should be -1 if there is no lesser
          // actually it's a pain 
          if(textFieldIndex!=-1){
            ((TextField) getComponent(textFieldIndex, 3, table)).setStyle("");
          }
          if(isAllFilled(table)){ // if all filled ( you already have this method)
             if(hasValidValue(table,numRows)){ // check for validity
                button.setDisable(false); // then make the button active again
             }
             else{// if it's not a valid value
                  // re-style the TextField which has lesser value
                 ((TextField) getComponent(textFieldIndex, 3, table)).
                                        setStyle("-fx-border-color: red;");
                  button.setDisable(true); 
             }
          }
          else{
               button.setDisable(true);
          }
       });
     }  
   }
}

现在在tabPane ChangeListener中添加方法的第三个para(因为你已经拥有它,你只需要添加ComboBox的值：

tabPane.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<Tab>(){
   ....
   ....
   ....
   // I think you have here anchorPane not containerB in the original code
   validateTable((GridPane) containerB.getChildren().get(0), test, comboBox.getValue());
}

测试

标签：java,javafx,javafx-8,javafx-2
来源： https://codeday.me/bug/20191009/1875652.html