我在GWT中设置FormPanel的backgroundcolor时遇到问题。 我发现可以使用以下代码片段更改backgroundcolor。 所以我在构造函数中添加了一行来更改面板背景：
this.fpDefaultColorBlack.getElement().getStyle().setBackgroundColor("#000000");
（this.fpDefaultColorBlack是一个FormPanel）
我的问题是，在启动我的程序后，面板backgroundcolor是它的默认颜色，只有当我与这个FormPanel交互时它的颜色会发生变化。
有没有办法刷新面板？我正在寻找几个小时的解决方案......
btw。：所有使用的组件都来自lib：com.extjs.gxt.ui.client.widget 以下是它实际外观的预览： http://www.directupload.net/file/d/3503/hq6pii62_png.htm
这是全班的代码：
package de.rwthaachen.imib.cua.client.imageAnnotation;
public class ColorPickerDialog extends Window{
/** ToolBoxPanel to be able to return the color from this window */
private ToolBoxPanel tbp;
/** Color in hexadecimal-format */
private String selectedColor;
/** FormPanel, which is used to show the current selectedColor */
private FormPanel colorVisualization;
/** Slider to change the red-value of selectedColor (0-255)*/
private Slider sliderRed;
/** Slider to change the green-value of selectedColor (0-255)*/
private Slider sliderGreen;
/** Slider to change the blue-value of selectedColor (0-255)*/
private Slider sliderBlue;
/** NumberField to show the sliders values (0-255)*/
private NumberField nfRed;
/** NumberField to show the sliders values (0-255)*/
private NumberField nfGreen;
/** NumberField to show the sliders values (0-255)*/
private NumberField nfBlue;
/** Listener for Default-Colors(onclick) */
private Listener<BaseEvent> lFormPanelListener;
/** red-value of selectedColor*/
private int redValue;
/** green-value of selectedColor*/
private int greenValue;
/** blue-value of selectedColor*/
private int blueValue;
/** Button to save changes and return to the ToolBoxPanel*/
private Button btnOK;
/** Button to close the window without saving */
private Button btnCancel;
private FormPanel fpDefaultColorBlack;
private FormPanel fpDefaultColorWhite;
private FormPanel fpDefaultColorRed;
private FormPanel fpDefaultColorGreen;
private FormPanel fpDefaultColorBlue;
public ColorPickerDialog(ToolBoxPanel tbp, String color){
super();
this.tbp = tbp;
this.selectedColor = color;
this.initMainWindow();
this.initComponents();
}
private void initMainWindow(){
this.setSize(290, 230);
this.setLayout(new AbsoluteLayout());
this.setResizable(false);
this.setModal(true);
this.setBlinkModal(true);
}
private void initComponents(){
this.updateColorRGB();
this.initFormPanelListener();
/* ***************************
* RED
* **************************/
Label lblRed = new Label("Red:");
lblRed.setWidth(50);
this.add(lblRed, new AbsoluteData(6, 6));
this.sliderRed = new Slider();
this.sliderRed.setMinValue(0);
this.sliderRed.setMaxValue(255);
this.sliderRed.setValue(this.redValue);
this.sliderRed.setIncrement(1);
this.sliderRed.setWidth(150);
this.sliderRed.setMessage("{0}");
this.sliderRed.addListener(Events.Change, new Listener<SliderEvent>(){
@Override
public void handleEvent(SliderEvent be) {
// Set redValue and nfRed to the sliders value and update the colorPanels color
redValue = sliderRed.getValue();
nfRed.setValue(redValue);
updateColorHex();
}
});
this.add(sliderRed, new AbsoluteData(50,6));
this.nfRed = new NumberField();
this.nfRed.setWidth(30);
this.nfRed.setReadOnly(true);
this.nfRed.setValue(this.redValue);
this.add(this.nfRed, new AbsoluteData(210,6));
/* ***************************
* GREEN
* **************************/
Label lblGreen = new Label("Green:");
lblGreen.setWidth(50);
this.add(lblGreen, new AbsoluteData(6, 34));
this.sliderGreen = new Slider();
this.sliderGreen.setMinValue(0);
this.sliderGreen.setMaxValue(255);
this.sliderGreen.setValue(this.greenValue);
this.sliderGreen.setIncrement(1);
this.sliderGreen.setWidth(150);
this.sliderGreen.setMessage("{0}");
this.sliderGreen.addListener(Events.Change, new Listener<SliderEvent>(){
@Override
public void handleEvent(SliderEvent be) {
// Set greenValue and nfGreen to the sliders value and update the colorPanels color
greenValue = sliderGreen.getValue();
nfGreen.setValue(greenValue);
updateColorHex();
}
});
this.add(sliderGreen, new AbsoluteData(50,34));
this.nfGreen = new NumberField();
this.nfGreen.setWidth(30);
this.nfGreen.setReadOnly(true);
this.nfGreen.setValue(this.greenValue);
this.add(this.nfGreen, new AbsoluteData(210,34));
/* ***************************
* BLUE
* **************************/
Label lblBlue = new Label("Blue:");
lblBlue.setWidth(50);
this.add(lblBlue, new AbsoluteData(6, 62));
this.sliderBlue = new Slider();
this.sliderBlue.setMinValue(0);
this.sliderBlue.setMaxValue(255);
this.sliderBlue.setValue(this.blueValue);
this.sliderBlue.setIncrement(1);
this.sliderBlue.setWidth(150);
this.sliderBlue.setMessage("{0}");
this.sliderBlue.addListener(Events.Change, new Listener<SliderEvent>(){
@Override
public void handleEvent(SliderEvent be) {
// Set blueValue and nfBlue to the sliders value and update the colorPanels color
blueValue = sliderBlue.getValue();
nfBlue.setValue(blueValue);
updateColorHex();
}
});
this.add(sliderBlue, new AbsoluteData(50,62));
this.nfBlue = new NumberField();
this.nfBlue.setWidth(30);
this.nfBlue.setReadOnly(true);
this.nfBlue.setValue(this.blueValue);
this.add(this.nfBlue, new AbsoluteData(210,62));
/* ***************************
* COLOR PANEL
* **************************/
this.colorVisualization = new FormPanel();
this.colorVisualization.setSize(20, 80);
this.colorVisualization.setHeaderVisible(false);
this.add(colorVisualization, new AbsoluteData(250, 6));
this.updateColorHex();
/* ***************************
* DEFAULT COLOR PANELS
* **************************/
Label lblDefaultColors = new Label("Default Colors:");
lblBlue.setWidth(80);
this.add(lblDefaultColors, new AbsoluteData(6, 90));
this.fpDefaultColorBlack = new FormPanel();
this.fpDefaultColorBlack.setWidth(20);
this.fpDefaultColorBlack.setHeaderVisible(false);
this.fpDefaultColorBlack.getElement().getStyle().setBackgroundColor("#000000");
this.add(fpDefaultColorBlack, new AbsoluteData(100, 90));
this.fpDefaultColorBlack.addListener(Events.OnClick, this.lFormPanelListener);
this.fpDefaultColorWhite = new FormPanel();
this.fpDefaultColorWhite.setWidth(20);
this.fpDefaultColorWhite.setHeaderVisible(false);
this.fpDefaultColorWhite.getElement().getStyle().setBackgroundColor("#FFFFFFF");
this.add(fpDefaultColorWhite, new AbsoluteData(130, 90));
this.fpDefaultColorWhite.addListener(Events.OnClick, this.lFormPanelListener);
this.fpDefaultColorRed = new FormPanel();
this.fpDefaultColorRed.setWidth(20);
this.fpDefaultColorRed.setHeaderVisible(false);
this.fpDefaultColorRed.getElement().getStyle().setBackgroundColor("#FF0000");
this.add(fpDefaultColorRed, new AbsoluteData(160, 90));
this.fpDefaultColorRed.addListener(Events.OnClick, this.lFormPanelListener);
this.fpDefaultColorGreen = new FormPanel();
this.fpDefaultColorGreen.setWidth(20);
this.fpDefaultColorGreen.setHeaderVisible(false);
this.fpDefaultColorGreen.getElement().getStyle().setBackgroundColor("#00FF00");
this.add(fpDefaultColorGreen, new AbsoluteData(190, 90));
this.fpDefaultColorGreen.addListener(Events.OnClick, this.lFormPanelListener);
this.fpDefaultColorBlue = new FormPanel();
this.fpDefaultColorBlue.setWidth(20);
this.fpDefaultColorBlue.setHeaderVisible(false);
this.fpDefaultColorBlue.getElement().getStyle().setBackgroundColor("#0000FF");
this.add(fpDefaultColorBlue, new AbsoluteData(220, 90));
this.fpDefaultColorBlue.addListener(Events.OnClick, this.lFormPanelListener);
/* ***************************
* BUTTON OK
* **************************/
this.btnOK = new Button("Apply");
this.btnOK.setSize(88, 22);
this.btnOK.addSelectionListener(new SelectionListener<ButtonEvent>() {
@Override
public void componentSelected(ButtonEvent ce) {
// Save changes and close window
tbp.setSelectedColor(selectedColor);
tbp.updateColor();
hide();
}
});
this.add(this.btnOK, new AbsoluteData(185, 146));
/* ***************************
* BUTTON CANCEL
* **************************/
this.btnCancel = new Button("Cancel");
this.btnCancel.setSize(88, 22);
this.btnCancel.addSelectionListener(new SelectionListener<ButtonEvent>() {
@Override
public void componentSelected(ButtonEvent ce) {
// Throw changes and close window
hide();
}
});
this.add(this.btnCancel, new AbsoluteData(185, 174));
}
/**
* Calculate redValue, greenValue and blueValue by converting hex-format to binary-format
*/
private void updateColorRGB(){
int r1 = 0, r2 = 0, g1 = 0, g2 = 0, b1 = 0, b2 = 0;
for(int i = 1; i < this.selectedColor.length(); i++){
char currentChar = this.selectedColor.charAt(i);
int currentCharValue;
if(currentChar < 58){
currentCharValue = currentChar - 48;
}
else{
currentCharValue = currentChar - 55;
}
switch(i){
case 1:
r1 = currentCharValue;
break;
case 2:
r2 = currentCharValue;
break;
case 3:
g1 = currentCharValue;
break;
case 4:
g2 = currentCharValue;
break;
case 5:
b1 = currentCharValue;
break;
case 6:
b2 = currentCharValue;
break;
}
}
this.redValue = r1 * 16 + r2;
this.greenValue = g1 * 16 + g2;
this.blueValue = b1 * 16 + b2;
}
/**
* Convert redValue, greenValue and blueValue to hex-format and update selectedColor + colorVisualization-panel
*/
private void updateColorHex(){
String rString = Integer.toHexString(this.redValue);
if(this.redValue == 0){
rString = "0" + rString;
}
String gString = Integer.toHexString(this.greenValue);
if(this.greenValue == 0){
gString = "0" + gString;
}
String bString = Integer.toHexString(this.blueValue);
if(this.blueValue == 0){
bString = "0" + bString;
}
this.selectedColor = "#" + rString + gString + bString;
this.colorVisualization.getElement().getStyle().setBackgroundColor(this.selectedColor);
this.colorVisualization.repaint();
}
/**
* Initialize Listener for all default color-panels (black, white, red, green, blue)
* Sets all colors, depending on which formPanel was clicked on
*/
private void initFormPanelListener(){
this.lFormPanelListener = new Listener<BaseEvent>(){
@Override
public void handleEvent(BaseEvent be) {
// Set selectedColor depending on which FormPanel was clicked on
if(be.getSource().equals(fpDefaultColorBlack)){
selectedColor = "#000000";
}
else if(be.getSource().equals(fpDefaultColorWhite)){
selectedColor = "#FFFFFF";
}
else if(be.getSource().equals(fpDefaultColorRed)){
selectedColor = "#FF0000";
}
else if(be.getSource().equals(fpDefaultColorGreen)){
selectedColor = "#00FF00";
}
else if(be.getSource().equals(fpDefaultColorBlue)){
selectedColor = "#0000FF";
}
updateColorRGB();
sliderBlue.setValue(blueValue);
sliderRed.setValue(redValue);
sliderGreen.setValue(greenValue);
}
};
}
}
答案 0 :(得分：0)
我尝试将代码FormPanel添加到RootPanel并添加到UI-Binder，并且确实渲染正常，无需进行交互以便查看更改。你能提供更多代码吗？同时有一种叫onFrameLoad()的方法，但我不知道它是否符合您的目的。