JavaFx：如何比較GridPane中動態創建的TextField的值？

Question

我正在開發使用JavaFX中，我創建一個GridPane內動態文本字段和有它最初像這樣禁用的按鈕的應用程序：

所以，我要的是，如果第1列TextField的值小於第3個的TextField值，按鈕應使這樣的：

但我們說，如果任何列3文本字段值變得小於同一行的第1個文本字段的值，它應該disab樂按鈕，並以紅色顯示的具體文本字段邊緣，當鼠標懸停在該字段應該顯示一些警告：

我創建文本字段是這樣的：

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; 
    } 

我之後創建另一種方法來返回組件在特定行和列如下：

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; 
    } 

我試圖做這樣的b UT它不工作（在這裏，我將值轉換成字符串和公正的檢查比較）：

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; 
    } 

Answer 1

其實它不是那麼容易做到你想要什麼，因爲你的代碼都需要進行重構（代碼並不意味着做這種先進的要求，但它的優良的基本要求你有）。然而，你可以做這樣的事情：

首先，定義一個全球變量與無效TextField（的last row index從這裏你就斷定這將改變邊框顏色爲更新ONE無效TextField同時）：

public static int textFieldIndex = -1; 

與方法的幫助下，你已經有了getComponent (int row, int column, GridPane table)，創建另一個靜態方法我們檢查ALLTextFields具有有效值一次：

/** 
* 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; 
} 

現在，您需要使用上面的方法在validateTable()方法，並做一些調整：

// 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); 
      } 
     }); 
    } 
    } 
} 

現在，在您tabPane ChangeListener添加方法的第三段（因爲您已經擁有它，您只需添加值ComboBox：

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()); 
} 

---

測試

Answer 2

您可以創建在創建文本字段做驗證綁定。這將避免需要瀏覽網格窗格的子節點，這看起來不太健壯。

聲明布爾綁定的數組（會有每行一個）：

private BooleanBinding[] rowValidationBindings ; 

然後，你可以做

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

    rowValidationBindings = new BooleanBinding[rows]; 

    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); 

     rowValidationBindings[i] = Bindings.createBooleanBinding(
      () -> { 
       if (textField1.getText().matches("\\d+") && 
        textField3.getText().matches("\\d+")) { 
        int value1 = Integer.parseInt(textField1.getText()); 
        int value3 = Integer.parseInt(textFIeld3.getText()); 
        return value3 > value1 ; 
       } else { 
        return false ; 
       } 
      }, textField1.textProperty(), textField2.textProperty() 
     ); 

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

    button.disableProperty().bind(Bindings.createBooleanBinding(
     () -> ! Stream.of(rowValidationBindings).allMatch(BooleanBinding::get), 
     rowValidationBindings 
    )); 

    return table; 
} 

您還可以添加樣式到文本字段直接在在for循環：

textField3.styleProperty().bind(Bindings 
    .when(rowValidationBindings[i]) 
    .then("") 
    .otherwise("-fx-border-color: red")); // or whatever you are using for style 

和工具提示：

Tooltip tooltip = new Tooltip(); 
tooltip.textProperty().bind(Bindings.concat("Value must be greater than ",textField1.textProperty())); 
textField3.tooltipProperty().bind(Bindings 
    .when(rowValidationBindings[i]) 
    .then((Tooltip)null) 
    .otherwise(tooltip));