AS3 CookBook学习整理(七)

1. 调整文本框大小以适应内容

设置autoSize属性可自动根据内容调整文本框大小。可用值为RIGHT, LEFT, CENTER,和NONE，都是flash.text.TextFieldAutoSize类常量

默认值为NONE，表示不自动调整大小。 另外，wordWrap属性设置为true，则当内容超出范围时自动换行。貌似必须先设置autoSize才生效

package {   
    import flash.display.Sprite;   
    import flash.text.TextField;   
    import flash.text.TextFieldAutoSize;   
    import flash.text.TextFieldType;   
  
    public class Sample0323 extends Sprite   
    {   
        public function Sample0323()   
        {   
            var text:TextField = new TextField();   
            text.type = TextFieldType.INPUT;   
            text.border = true;   
            text.borderColor = 0xFFFF00;   
            text.height = 20;   
  
            text.autoSize = TextFieldAutoSize.CENTER;   
            text.wordWrap = true;   
               
            this.addChild(text);   
        }   
    }   
}

2. 滚动文本

水平滚动的单位为像素(最小值为0)，垂直滚动的单位为行(最小值为1)。设置WheelEnabled=false可以禁用滚轮滚动行。

scrollH -- 水平滚动的像素

maxScrollH -- 文本的最大水平像素值，只读

scrollV -- 垂直滚动的行数

maxScrollV -- 文本的最大行数，只读

bottomScrollV -- 当前最后一行是第几行(在整个行数里)，只读

package {   
    import flash.display.Sprite;   
    import flash.events.MouseEvent;   
    import flash.text.TextField;   
    import flash.text.TextFieldAutoSize;   
    import flash.text.TextFieldType;   
  
    public class Sample0323 extends Sprite   
    {   
        private var textBox:TextField;   
        private var textInfo:TextField;   
           
        public function Sample0323()   
        {   
            textBox = new TextField();   
            textBox.type = TextFieldType.INPUT;   
               
            textBox.width = 250;   
            textBox.height = 100;   
            textBox.border = true;   
            textBox.borderColor = 0xFFFF00;   
            textBox.background = true;   
            textBox.backgroundColor = 0xFFFFFF;   
               
           //测试水平滚动则为false,垂直滚动则为true;    
            textBox.wordWrap = true;   
               
            this.addChild(textBox);   
           
            var label:TextField = new TextField();   
            label.x = 200;   
            label.y = 100;   
            label.background = true;   
            label.backgroundColor = 0xCCCCCC;   
            label.autoSize = TextFieldAutoSize.CENTER;   
            label.text = "水平滚动10个像素";   
            label.addEventListener(MouseEvent.CLICK,scrollH_onClick);   
            this.addChild(label);   
               
            label = new TextField();   
            label.x = 200;   
            label.y = 150;   
            label.background = true;   
            label.backgroundColor = 0xCCCCCC;   
            label.autoSize = TextFieldAutoSize.CENTER;   
            label.text = "水平滚动至结尾";   
            label.addEventListener(MouseEvent.CLICK,maxScrollH_onClick);   
            this.addChild(label);   
               
            label = new TextField();   
            label.x = 200;   
            label.y = 200;   
            label.background = true;   
            label.backgroundColor = 0xCCCCCC;   
            label.autoSize = TextFieldAutoSize.CENTER;   
            label.text = "垂直滚动3行";   
            label.addEventListener(MouseEvent.CLICK,scrollV_onClick);   
            this.addChild(label);   
               
            label = new TextField();   
            label.x = 200;   
            label.y = 250;   
            label.background = true;   
            label.backgroundColor = 0xCCCCCC;   
            label.autoSize = TextFieldAutoSize.CENTER;   
            label.text = "垂直滚动至结尾";   
            label.addEventListener(MouseEvent.CLICK,maxScrollV_onClick);   
            this.addChild(label);   
               
            textInfo = new TextField();   
            textInfo.type = TextFieldType.INPUT;   
            textInfo.y = 300;   
            textInfo.autoSize = TextFieldAutoSize.CENTER;   
               
            this.addChild(textInfo);   
        }   
           
        private function scrollH_onClick(event:MouseEvent):void   
        {   
            textBox.scrollH += 10;   
        }   
           
        private function maxScrollH_onClick(event:MouseEvent):void   
        {   
            textBox.scrollH = textBox.maxScrollH;   
        }   
           
        private function scrollV_onClick(event:MouseEvent):void   
        {   
            textBox.scrollV += 3;   
            textInfo.text = "当前最后一行在整个行数里是第"+textBox.bottomScrollV+"行";   
        }   
           
        private function maxScrollV_onClick(event:MouseEvent):void   
        {   
            textBox.scrollV = textBox.maxScrollV;   
        }   
    }   
}

3. 响应滚动事件

当水平或垂直滚动产生时会触发scroll事件，flash.events.Event类的SCROLL常量即代表该事件

package {   
    import flash.display.Sprite;   
    import flash.events.Event;   
    import flash.text.TextField;   
    import flash.text.TextFieldAutoSize;   
    import flash.text.TextFieldType;   
    import flash.utils.getTimer;   
  
    public class Sample0323 extends Sprite   
    {   
        private var textBox:TextField;   
        private var textInfo:TextField;   
           
        public function Sample0323()   
        {   
            textBox = new TextField();   
            textBox.type = TextFieldType.INPUT;   
               
            textBox.width = 250;   
            textBox.height = 100;   
            textBox.border = true;   
            textBox.borderColor = 0xFFFF00;   
            textBox.background = true;   
            textBox.backgroundColor = 0xFFFFFF;   
            textBox.wordWrap = true;   
               
            textBox.addEventListener(Event.SCROLL,onScroll);   
               
            this.addChild(textBox);    
               
            textInfo = new TextField();   
            textInfo.type = TextFieldType.INPUT;   
            textInfo.y = 300;   
            textInfo.autoSize = TextFieldAutoSize.CENTER;   
               
            this.addChild(textInfo);   
        }   
           
        private function onScroll(event:Event):void   
        {   
            textInfo.text = flash.utils.getTimer()+" -- 滚动了";   
        }   
    }   
}

4. 格式化文本框文本

有三种方式对文本进行格式化：HTML标签格式化、使用TextFormat对象、CSS样式

* HTML标签格式化示例： textBox.htmlText = "<B>粗体文本</B><U>下划线文本</U>";

* TextFormat对象示例：(注意：只对setTextFormat之前的代码有效)

var textFormat:TextFormat = new TextFormat();

textFormat.color = 0xFF0000;

textFormat.htmlText = "有效";

//也可以对部分文字进行格式化，例如:textBox.setTextFormat(textFormat,3,textBox.text.length);

textBox.setTextFormat(textFormat); textFormat.htmlText = "无效";

* CSS样式示例：(注意：只对CSS定义之后的代码有效)

var css:StyleSheet = new StyleSheet();

var styleObj:Object = {color:"#FF0000"};

css.setStyle(".stdStyle",styleObj);

textBox.styleSheet = css;

textBox.htmlText = "不潮不用花钱";

this.addChild(textBox);

package {   
    import flash.display.Sprite;   
    import flash.events.Event;   
    import flash.events.MouseEvent;   
    import flash.net.URLLoader;   
    import flash.net.URLRequest;   
    import flash.text.StyleSheet;   
    import flash.text.TextField;   
    import flash.text.TextFieldAutoSize;   
  
    public class Sample0324 extends Sprite   
    {          
        private var label:TextField;   
        private var text:String = "here comes <span class='stdText'>wayne</span>";   
           
        public function Sample0324()   
        {                      
            var btnRed:TextField = new TextField();   
            btnRed.text = "应用红色样式";   
            btnRed.y = 100;   
            btnRed.addEventListener(MouseEvent.CLICK,onRedClick);   
            this.addChild(btnRed);   
               
            var btnGreen:TextField = new TextField();   
            btnGreen.text = "应用绿色样式";   
            btnGreen.y = 200;   
            btnGreen.addEventListener(MouseEvent.CLICK,onGreenClick);   
            this.addChild(btnGreen);   
               
            label = new TextField();       
            label.autoSize = TextFieldAutoSize.CENTER;   
            label.htmlText = text;   
            this.addChild(label);   
        }   
           
        private function onRedClick(event:MouseEvent):void   
        {   
            var loader:URLLoader = new URLLoader();   
            loader.load(new URLRequest("StdStyle.css"));   
            loader.addEventListener(Event.COMPLETE,onLoadComplete);   
        }   
           
        private function onGreenClick(event:MouseEvent):void   
        {   
            var loader:URLLoader = new URLLoader();   
            loader.load(new URLRequest("StdStyle2.css"));   
            loader.addEventListener(Event.COMPLETE,onLoadComplete);   
        }   
           
        private function onLoadComplete(event:Event):void   
        {   
            var css:StyleSheet = new StyleSheet();   
            css.parseCSS((event.target  as  URLLoader).data);   
            label.styleSheet = css;    
               
            label.htmlText = text;   
        }      
    }   
}

5. 格式化用户输入的文本

应用TextFormat对象到文本框的defaultTextFormat属性上

package {   
    import flash.display.Sprite;   
    import flash.text.TextField;   
    import flash.text.TextFieldType;   
    import flash.text.TextFormat;   
  
    public class Sample0324 extends Sprite   
    {          
        public function Sample0324()   
        {                      
            var textBox:TextField = new TextField();   
            textBox.type = TextFieldType.INPUT;   
            textBox.border = true;   
            textBox.borderColor = 0xFFFF00;   
               
            var textFormat:TextFormat = new TextFormat();   
            textFormat.color = 0xFF0000;   
            textFormat.italic = true;   
               
            textBox.defaultTextFormat = textFormat;   
               
            this.addChild(textBox);   
        }   
    }   
}

6. 设置文本字体

使用HTML的标签，或者设置TextFormat对象的font属性，或者通过CSS的font-family属性

修改字体有多种方法，如果使用HTML的话可通过 标签更改：field.htmlText = "Formatted text";

也可设置TextFormat对象的font属性：formatter.font = "Arial";

或者在CSS中定义font-family 属性：p {font-family: Arial;}

需要注意的是电脑中必须要有你所指定的字体，因为有些电脑上可能没有安装相应的字体，这是可指定多种字体：formatter.font = "Arial, Verdana, Helvetica";

如果都没有指定字体，默认使用系统字体。

另外我们还可使用字体组，字体组是系统默认字体的一个分类，有三种： _sans, _serif, 和_typewriter。

_sans 组包含如Arial 或Helvetica，_serif组包含如Times 或Times New Roman，_typewriter 组包含如Courier 或Courier New

7. 嵌入字体

通过[embed]元数据嵌入字体，设置文本框的embedFonts属性为true，通过标签，TextFormat对象或CSS应用字体

嵌入系统字体:

[Embed(systemFont="Onyx",fontName="hxw",mimeType="application/x-font-truetype")]

嵌入非系统字体:

[Embed(source="xjlFont.fon",fontName="xjl",mimeType="application/x-font")]

可以设置textField.rotation += 30来设置文字旋转(放在定时器或OnEnterFrame事件里)，文字必须为嵌入字体，否则无法正常显示。

TextFormat方式

package {
 import flash.display.Sprite;
 import flash.text.TextField;
 import flash.text.TextFieldAutoSize;
 import flash.text.TextFormat;

 [Embed(source="xjlFont.fon",fontName="xjl",mimeType="application/x-font-truetype")]
 public class Sample0410 extends Sprite
 {
  public function Sample0410()
  { 
   var textBox:TextField = new TextField();
   textBox.text = "hello everybody,my name  is 老胡";
   textBox.autoSize = TextFieldAutoSize.CENTER;
   textBox.embedFonts=true;
   addChild(textBox);
   var formatter:TextFormat = new TextFormat();
   formatter.font = "xjl";
   formatter.size = 30;
   textBox.setTextFormat(formatter);
  }
 }
}

CSS方式

package {
 import flash.display.Sprite;
 import flash.text.StyleSheet;
 import flash.text.TextField;
 import flash.text.TextFieldAutoSize;

 [Embed(source="xjlFont.fon",fontName="xjl",mimeType="application/x-font-truetype")]
 public class Sample0410 extends Sprite
 {
  public function Sample0410()
  { 
   var css:StyleSheet = new StyleSheet();
   var styleObj:Object = {color:"#FFFF00", fontFamily:"xjl",fontSize:"30px"};
   css.setStyle(".stdStyle",styleObj);
   
   var textBox:TextField = new TextField();
   textBox.styleSheet = css;
   textBox.text = "<span class='stdStyle'>hello everybody,my name  is  老胡</span>";
   textBox.autoSize = TextFieldAutoSize.CENTER;
   textBox.embedFonts=true;
   addChild(textBox);
  }
 }
}

8. 设置焦点

设置stage.focus = xxx来设置舞台的焦点,stage.focus = null可以移除焦点

package {
 import flash.display.Sprite;
 import flash.events.MouseEvent;
 import flash.text.TextField;
 import flash.text.TextFieldType;
 public class Sample0410 extends Sprite
 { 
  public function Sample0410()
  { 
   var field:TextField = new TextField( );
   field.border = true;
   field.background = true;
   field.type = TextFieldType.INPUT;
   addChild(field);
   stage.addEventListener(MouseEvent.CLICK,onClick);
  }
  
  private function onClick(event:MouseEvent):void
  {
   stage.focus = getChildAt(0)  as  TextField;
   //this.removeEventListener(MouseEvent.CLICK,onClick);
  }
 }
}

9. 选中TextField的部分文本及设置光标所在位置

设置TextField.setSelection(startIndex,endIndex)，同时通过selectionBeginIndex和selectionEndIndex两个只读属性可获得选中文本的具体位置

如果设置setSelection的两个参数相同，则是在设置光标所在位置，通过TextField.caretIndex属性可以得到当前光标所在位置

package {
 import flash.display.Sprite;
 import flash.events.MouseEvent;
 import flash.text.TextField;
 import flash.text.TextFieldAutoSize;
 import flash.text.TextFieldType;
 public class Sample0410 extends Sprite
 { 
  private var lblNumber:TextField;
  
  public function Sample0410()
  { 
   var field:TextField = new TextField( );
   field.border = true;
   field.background = true;
   field.type = TextFieldType.INPUT;
   field.text = "我们的祖先在护佑着你";
   this.addChild(field);
   
   lblNumber = new TextField();
   lblNumber.autoSize = TextFieldAutoSize.CENTER;
   lblNumber.background = true;
   lblNumber.y = 150;
   this.addChild(lblNumber);
   
   field.addEventListener(MouseEvent.CLICK,onClick);
  }
  
  private function onClick(event:MouseEvent):void
  {
   var textBox:TextField = event.target  as  TextField;
   textBox.setSelection(5,5);
   var strStart:String = "起始点："+textBox.selectionBeginIndex.toString();
   var strEnd:String = "结束点："+textBox.selectionEndIndex.toString();
   var currentIndex:String = "当前光标所在："+textBox.caretIndex;
   lblNumber.text = strStart + "," + strEnd + "," + currentIndex;
  }
 }
}

10. 取消事件的默认行为(如果可以取消)

默认情况下，许多事件都有Flash Player执行的关联行为。例如，如果用户在文本字段中键入一个字符，则默认行为就是在文本字段中显示该字符。可以使用preventDefault()方法来防止显示该字符

然后很多事件是瞬发的，像点击事件、获得焦点、失去焦点事件

可以使用Event.cancelable属性来判断是否可以取消行为，如果返回true，则可以使用preventDefault()来取消事件；否则preventDefault()无效

package {
 import flash.display.Sprite;
 import flash.events.FocusEvent;
 import flash.events.MouseEvent;
 import flash.text.TextField;
 import flash.text.TextFieldType;
 public class Sample0410 extends Sprite
 {
  public function Sample0410()
  {
   //演示MouseEvent.Click事件是无法取消行为的
   stage.addEventListener(MouseEvent.CLICK,onClick);
   
   //演示FocusEvent.FOCUS_IN事件是无法取消行为的
   var textBox:TextField = new TextField();
   textBox.type = TextFieldType.INPUT;
   textBox.background = true;
   textBox.addEventListener(FocusEvent.FOCUS_IN,onFocusIn);
   this.addChild(textBox);
   
   //演示FocusEvent.MOUSE_FOCUS_CHANGE事件是可以取消行为的
   textBox.addEventListener(FocusEvent.MOUSE_FOCUS_CHANGE,onMouseFocusChange);
  }
  
  private function onClick(event:MouseEvent):void
  {
   trace("MouseEvent.Click事件可以取消行为吗？" + event.cancelable);//显示false
  }
  
  private function onFocusIn(event:FocusEvent):void
  {
   trace("FocusEvent.FOCUS_IN事件可以取消行为吗？" + event.cancelable);//显示false
  }
  
  private function onMouseFocusChange(event:FocusEvent):void
  {
   trace("FocusEvent.MOUSE_FOCUS_CHANGE事件可以取消行为吗？" + event.cancelable);//显示true
  }
 }
}