自定义控件之文字绘制

paint与文字设置相关的方法如下

        paint.setStrokeWidth(5);//画笔宽度
        paint.setColor(Color.RED);//设置颜色
        paint.setAntiAlias(true);//抗锯齿功能
        paint.setStyle(Paint.Style.FILL);//样式
        paint.setTextAlign(Paint.Align.CENTER);//文字对齐方式
        paint.setTextSize(50);//设置文字大小
        paint.setFakeBoldText(true);//设置是否为粗体
        paint.setUnderlineText(true);//设置下画线
        paint.setTextSkewX(-0.25f);//字体倾斜度,一般设置为-0.25
        paint.setStrikeThruText(true);//设置带有删除线效果
        paint.setTextScaleX(2);//水平拉伸,高度不会变

示例代码

 /**
     * 填充样式的区别
     * @param canvas
     */
    private void setStyle(Canvas canvas){
        Paint paint=new Paint();
        paint.setColor(Color.RED);  //设置画笔颜色

        paint.setStrokeWidth (5);//设置画笔宽度
        paint.setAntiAlias(true); //指定是否使用抗锯齿功能，如果使用，会使绘图速度变慢
        paint.setTextSize(80);//设置文字大小

//绘图样式，设置为填充
        paint.setStyle(Paint.Style.FILL);
        canvas.drawText("床前明月光", 10,100, paint);
    }

    /**
     * setTextAlign
     * @param canvas
     */
    private void setAlign(Canvas canvas){

        Paint paint=new Paint();
        paint.setColor(Color.RED);

        paint.setStrokeWidth (5);
        paint.setAntiAlias(true);
        paint.setTextSize(80);
        paint.setTextAlign(Paint.Align.RIGHT);

        canvas.drawText("床前明月光", 400,100, paint);
    }

    /**
     *  设置字体样式_常规设置
     * @param canvas
     */
    private void setTextStyle(Canvas canvas){
        Paint paint=new Paint();
        paint.setColor(Color.RED);
        paint.setTextSize(80);
        canvas.drawText("床前明月光", 10,100, paint);

        paint.setFakeBoldText(true);//设置是否为粗体文字
        paint.setUnderlineText(true);//设置下划线
        paint.setStrikeThruText(true);//设置带有删除线效果
        canvas.drawText("床前明月光", 10,250, paint);
    }

    /**
     *  设置字体样式_字体倾斜度设置
     * @param canvas
     */
    private void setTextSkewX(Canvas canvas){
        Paint paint=new Paint();
        paint.setColor(Color.RED);
        paint.setTextSize(80);
        //正常样式
        canvas.drawText("床前明月光", 10,100, paint);

        //向右倾斜
        paint.setTextSkewX(-0.25f);
        canvas.drawText("床前明月光", 10,200, paint);

        //向左倾斜
        paint.setTextSkewX(0.25f);
        canvas.drawText("床前明月光", 10,300, paint);
    }

    /**
     *  水平拉伸
     * @param canvas
     */
    private void setTextScaleX(Canvas canvas){
        Paint paint=new Paint();
        paint.setColor(Color.RED);
        paint.setTextSize(80);
        //正常样式
        canvas.drawText("床前明月光", 10,100, paint);
        //拉伸两倍
        paint.setTextScaleX(2);
        canvas.drawText("床前明月光", 10,200, paint);
    }

其他方法绘制

 /**
     *  普通绘制
     *
     * @param canvas
     */
    private void drawSubText(Canvas canvas) {
        Paint paint = new Paint();
        paint.setColor(Color.RED);
        paint.setTextSize(80);

        canvas.drawText("床前明月光", 2, 4, 10, 100, paint);
    }

    /**
     * 逐个指定文字位置
     */
    private void drawPosText(Canvas canvas) {
        Paint paint = new Paint();
        paint.setColor(Color.RED);
        paint.setTextSize(80);

        float[] pos = new float[]{80, 100,
                80, 200,
                80, 300,
                80, 400};
        canvas.drawPosText("床前明月", pos, paint); //pos绘制每个文字的具体位置,两两一组
    }

    /**
     * 沿路径绘制
     * @param canvas
     */
    private void drawPathText(Canvas canvas) {
        Paint paint = new Paint();
        paint.setColor(Color.RED);
        paint.setStrokeWidth(5);
        paint.setTextSize(45);
        paint.setStyle(Paint.Style.STROKE);

        //先创建两个相同的圆形路径，并先画出两个路径原图
        Path circlePath = new Path();
        circlePath.addCircle(220, 300, 150, Path.Direction.CCW);//逆向绘制
        canvas.drawPath(circlePath, paint);//绘制出路径原形

        Path circlePath2 = new Path();
        circlePath2.addCircle(600, 300, 150, Path.Direction.CCW);
        canvas.drawPath(circlePath2, paint);//绘制出路径原形

        String string = "床前明月光,疑是地上霜";
        paint.setColor(Color.GREEN);
        //hoffset、voffset参数值全部设为0，看原始状态是怎样的
        canvas.drawTextOnPath(string, circlePath, 0, 0, paint);
        //第二个路径，改变hoffset、voffset参数值
        canvas.drawTextOnPath(string, circlePath2, 80, 30, paint);

    }

    /**
     * 自字义字体
     * @param canvas
     */
    private void drawCustomFont(Canvas canvas){
        //自定义字体，，，迷你简罗卜
        Paint paint=new Paint();
        paint.setColor(Color.RED);
        paint.setTextSize(60);

        AssetManager mgr= mContext.getAssets();//得到AssetManager
        //根据路径得到Typeface
        Typeface typeface=Typeface.createFromAsset(mgr, "fonts/jian_luobo.ttf");
        paint.setTypeface(typeface);//设置字体样式
        canvas.drawText("床前明月光,疑是地上霜",10,550, paint);
    }

defaultFromStyle函数

public static Typeface defaultFromStyle(int style)

该函数会指定字体样式获取对于的默认字体,取值如下

BOLD 粗体
BOLD_ITALIC粗斜体
ITALIC斜体
NORMAL 正常字体 默认

示例

       Typeface typeface = Typeface.defaultFromStyle(Typeface.BOLD);
        paint.setTypeface(typeface);

Typeface 中create函数

该函数直接通过指定字体名来加载系统中自带的字体样式,如果字体不存在,则使用系统样式代替返回

示例:

        Typeface typeface = Typeface.create("宋体",Typeface.NORMAL);
        paint.setTypeface(typeface);