黑莓垂直滚动文本框

Question

我是黑莓开发的新手。我想在我的应用程序中做自定义文本框。

我写了一个代码，但我想滚动文本字段中的文本（如果我在文本框上面的文字4线延伸）。

我使用管理器类添加垂直滚动，但不能得到它。

TextField textfield1=new TextField(Manager.VERTICAL_SCROLL); 

任何人都知道如何垂直滚动到文本字段。

Answer 1

试试下面的代码：

import net.rim.device.api.ui.Graphics; 
import net.rim.device.api.ui.Manager; 
import net.rim.device.api.ui.component.TextField; 
import net.rim.device.api.ui.container.VerticalFieldManager; 

public class MyTextField extends VerticalFieldManager { 

    private int fieldWidth; 
    private int fieldHeight; 
    private TextField textField; 

    public MyTextField(int width, int height) { 

     super(Manager.NO_VERTICAL_SCROLL); 
     fieldWidth = width; 
     fieldHeight = height; 

     VerticalFieldManager vfm = new VerticalFieldManager(Manager.VERTICAL_SCROLL|Manager.VERTICAL_SCROLLBAR); 

     textField = new TextField() { 
      public void paint(Graphics g) { 
       getManager().invalidate(); 
       super.paint(g); 
      } 
     }; 

     vfm.add(textField); 
     add(vfm); 
    } 

    public void paint(Graphics g) { 
     // draw the border of the text area; 
     int color = g.getColor(); 
     g.setColor(0x00FFCC); 
     g.drawRect(0, 0, fieldWidth, fieldHeight); 
     g.setColor(color); 
     super.paint(g); 
    } 

    public void sublayout(int width, int height) { 
     if (fieldWidth == 0) { 
      fieldWidth = width; 
     } 
     if (fieldHeight == 0) { 
      fieldHeight = height; 
     } 
     super.sublayout(fieldWidth, fieldHeight); 
     setExtent(fieldWidth,fieldHeight); 
    } 

    public String getText() { 
     return textField.getText(); 
    } 
    public void setText(String text) { 
     textField.setText(text); 
    } 
} 

它通过指定这样的尺寸添加到您Screen或Manager：

add(new MyTextField(200, 200)); 

Answer 2

创建

HorizontalFieldManager HorizontalFieldManager=new HorizontalFieldManager(Manager.VERTICAL_SCROLL); 

然后

TextField textfield1=new TextField(); 
HorizontalFieldManager.add(textfield1); 
add(HorizontalFieldManager); 

Answer 3

可以使用自定义的文本框为波纹管。

public class CustomTextBox extends Manager 
{ 

/** 
* Default margins 
*/ 
private final static int DEFAULT_LEFT_MARGIN = 10; 
private final static int DEFAULT_RIGHT_MARGIN = 10; 
private final static int DEFAULT_TOP_MARGIN = 5; 
private final static int DEFAULT_BOTTOM_MARGIN = 5; 

/** 
* Default paddings 
*/ 
private final static int DEFAULT_LEFT_PADDING = 10; 
private final static int DEFAULT_RIGHT_PADDING = 10; 
private final static int DEFAULT_TOP_PADDING = 5; 
private final static int DEFAULT_BOTTOM_PADDING = 5; 

/** 
* Margins around the text box 
*/ 
private int topMargin = DEFAULT_TOP_MARGIN; 
private int bottomMargin = DEFAULT_BOTTOM_MARGIN; 
private int leftMargin = DEFAULT_LEFT_MARGIN; 
private int rightMargin = DEFAULT_RIGHT_MARGIN; 

/** 
* Padding around the text box 
*/ 
private int topPadding = DEFAULT_TOP_PADDING; 
private int bottomPadding = DEFAULT_BOTTOM_PADDING; 
private int leftPadding = DEFAULT_LEFT_PADDING; 
private int rightPadding = DEFAULT_RIGHT_PADDING; 

/** 
* Amount of empty space horizontally around the text box 
*/ 
private int totalHorizontalEmptySpace = leftMargin + leftPadding 
           + rightPadding + rightMargin; 

/** 
* Amount of empty space vertically around the text box 
*/ 
private int totalVerticalEmptySpace = topMargin + topPadding 
           + bottomPadding + bottomMargin; 

/** 
* Minimum height of the text box required to display the text entered 
*/ 
private int minHeight = getFont().getHeight() + totalVerticalEmptySpace; 

/** 
* Width of the text box 
*/ 
private int width = Display.getWidth(); 

/** 
* Height of the text box 
*/ 
private int height = minHeight; 

/** 
* Background image for the text box 
*/ 
private EncodedImage backgroundImage; 

/** 
* Bitmap version of the backgroundImage. 
* Needed to reduce the calculation overhead incurred by 
* scaling of the given image 
* and derivation of Bitmap from the 
* EncodedImage every time it is needed. 
*/ 
private Bitmap bitmapBackgroundImage; 

/** 
* The core element of this text box 
*/ 
private EditField editField; 
//private BasicEditField editField; 

//private String entireText; 

public CustomTextBox() 
{ 
    // Let the super class initialize the core 
    super(0); 

    // An edit field is the sole field of this manager. 
    editField = new EditField(); 
    //editField = new CustomEditField(); 
    add(editField); 
} 

public CustomTextBox(EncodedImage backgroundImage) 
{ 
    this();   
    setBackgroundImage(backgroundImage); 
} 

public void setSize(int width, int height) 
{ 
    boolean isChanged = false; 

    if (width > 0 // Ignore invalid width 
      && this.width != width) 
    { 
     this.width = width; 
     isChanged = true; 
    } 

    // Ignore the specified height if it is less 
    // than the minimum height required to display the text. 
    if (height > minHeight && height != this.height) 
    { 
     this.height = height; 
     isChanged = true; 
    } 

    // If width/height has been changed and background image 
    // is available, adapt it to the new dimension 
    if (isChanged == true && backgroundImage != null) 
    { 
     bitmapBackgroundImage = getScaledBitmapImage(backgroundImage, 
           this.width - (leftMargin+rightMargin), 
           this.height - (topMargin+bottomMargin)); 
    } 
} 

public void setWidth(int width) 
{ 

    if (width > 0 && width != this.width) 
    { 
     this.width = width; 

     // If background image is available, adapt it to the new width 
     if (backgroundImage != null) 
     { 
      bitmapBackgroundImage = getScaledBitmapImage(backgroundImage, 
            this.width - (leftMargin+rightMargin), 
            this.height - (topMargin+bottomMargin)); 
     } 
    } 
} 

public void setHeight(int height) 
{ 
    // Ignore the specified height if it is 
    // less than the minimum height required to display the text. 
    if (height > minHeight) 
    { 
     this.height = height; 

     // If background image is available, adapt it to the new width 
     if (backgroundImage != null) 
     { 
      bitmapBackgroundImage = getScaledBitmapImage(backgroundImage, 
            this.width - (leftMargin+rightMargin), 
            this.height - (topMargin+bottomMargin)); 
     } 
    } 
} 

public void setBackgroundImage(EncodedImage backgroundImage) 
{ 
    this.backgroundImage = backgroundImage; 

    // Consider the height of background image in 
    // calculating the height of the text box. 
    // setHeight() does not ensure that specified 
    // height will be in effect, of course, for valid reasons. 
    // So derivation of Bitmap image in the setHeight() method is not sure. 
    setHeight(backgroundImage.getHeight() + topMargin + bottomMargin); 
    if (bitmapBackgroundImage == null) 
    { 
     bitmapBackgroundImage = getScaledBitmapImage(backgroundImage, 
           this.width - (leftMargin+rightMargin), 
           this.height - (topMargin+bottomMargin)); 
    } 
} 

/** 
* Generate and return a Bitmap Image scaled according 
* to the specified width and height. 
* 
* @param image  EncodedImage object 
* @param width  Intended width of the returned Bitmap object 
* @param height Intended height of the returned Bitmap object 
* @return Bitmap object 
*/ 

private Bitmap getScaledBitmapImage(EncodedImage image, int width, int height) 
{ 
    // Handle null image 
    if (image == null) 
    { 
     return null; 
    } 

    int currentWidthFixed32 = Fixed32.toFP(image.getWidth()); 
    int currentHeightFixed32 = Fixed32.toFP(image.getHeight()); 

    int requiredWidthFixed32 = Fixed32.toFP(width); 
    int requiredHeightFixed32 = Fixed32.toFP(height); 

    int scaleXFixed32 = Fixed32.div(currentWidthFixed32, requiredWidthFixed32); 
    int scaleYFixed32 = Fixed32.div(currentHeightFixed32, requiredHeightFixed32); 

    image = image.scaleImage32(scaleXFixed32, scaleYFixed32); 

    return image.getBitmap(); 
} 


protected void sublayout(int width, int height) 
{ 
    // We have one and only child - the edit field. 
    // Place it at the appropriate place. 
    Field field = getField(0); 
    layoutChild(field, this.width - totalHorizontalEmptySpace, 
       this.height - totalVerticalEmptySpace); 
    setPositionChild(field, leftMargin+leftPadding, topMargin+topPadding); 

    setExtent(this.width, this.height); 
} 

public void setTopMargin(int topMargin) 
{ 
    this.topMargin = topMargin; 
} 

public void setBottomMargin(int bottomMargin) 
{ 
    this.bottomMargin = bottomMargin; 
} 

protected void paint(Graphics graphics) 
{ 
    // Draw background image if available, otherwise draw a rectangle 
    if (bitmapBackgroundImage == null) 
    { 


    graphics.drawRect(leftMargin, topMargin, 
//        width - (leftMargin+rightMargin), 
//        height - (topMargin+bottomMargin)); 
      graphics.drawRoundRect(leftMargin, topMargin, 
            width - (leftMargin+rightMargin), 
            height - (topMargin+bottomMargin), 5, 5); 
     } 
     else 
     { 
      graphics.drawBitmap(leftMargin, topMargin, 
           width - (leftMargin+rightMargin), 
           height - (topMargin+bottomMargin), 
           bitmapBackgroundImage, 0, 0); 
     } 

    // Determine the rightward text that can fit into the visible edit field 

    EditField ef = (EditField)getField(0); 
    String entireText = ef.getText(); 

    boolean longText = false; 
    String textToDraw = ""; 
    Font font = getFont(); 
    int availableWidth = width - totalHorizontalEmptySpace; 
    if (font.getAdvance(entireText) <= availableWidth) 
    { 
     textToDraw = entireText; 
    } 
    else 
    { 
     int endIndex = entireText.length(); 
     for (int beginIndex = 1; beginIndex < endIndex; beginIndex++) 
     { 
      textToDraw = entireText.substring(beginIndex); 
      if (font.getAdvance(textToDraw) <= availableWidth) 
      { 
       longText = true; 
       break; 
      } 
     } 
    } 

    if (longText == true) 
    {   
     // Force the edit field display only the truncated text 
     ef.setText(textToDraw); 

     // Now let the components draw themselves 
     super.paint(graphics); 

     // Return the text field its original text 
     ef.setText(entireText); 
    } 
    else 
    { 
     super.paint(graphics); 
    } 
} 

public int getPreferredWidth() 
{ 
    return width; 
} 

public int getPreferredHeight() 
{ 
    return height; 
} 

protected boolean keyChar(char ch, int status, int time) 
{ 
    if (ch == Characters.ENTER) 
    { 
     return true; 
    } 
    else 
    { 
     return super.keyChar(ch, status, time); 
    } 
} 

public String getText() 
{ 
    return ((EditField)getField(0)).getText(); 
} 

public void setText(final String text) 
{ 
    ((EditField)getField(0)).setText(text); 
}  
}