【Android】自定义view的模版

自定义View

模版

publicclassCustomViewextendsView{

privatePaintmPaint;

privateFontMetricsIntmFontMetricsInt;

privateRectmRect;

privateintmWidth;

privateintmHeight;

privateintmPaddingStart;

privateintmPaddingEnd;

privateintmPaddingTop;

privateintmPaddingBottom;

privateintmLeft;

privateintmTop;

privateintmRight;

privateintmBottom;

privateContextmContext;

publicCustomView(Contextcontext,AttributeSetattrs,intdefStyleAttr){

super(context,attrs,defStyleAttr);

mContext=context;

initTool();

}

publicCustomView(Contextcontext,AttributeSetattrs){

this(context,attrs,0);

}

publicCustomView(Contextcontext){

this(context,null);

}

privatevoidinitTool(){

mPaint=newPaint(Paint.ANTI_ALIAS_FLAG);

mPaint.setStyle(Paint.Style.FILL_AND_STROKE);

mPaint.setTextSize(sp2Px(mContext,11));

mPaint.setTextAlign(Paint.Align.CENTER);

mRect=newRect();

mFontMetricsInt=mPaint.getFontMetricsInt();

}

@Override

protectedvoidonMeasure(intwidthMeasureSpec,intheightMeasureSpec){

mWidth=getSizeFromMeasureSpec(widthMeasureSpec,280);

mHeight=getSizeFromMeasureSpec(heightMeasureSpec,280);

mPaddingStart=getPaddingStart();

mPaddingEnd=getPaddingEnd();

mPaddingTop=getPaddingTop();

mPaddingBottom=getPaddingBottom();

mLeft=mPaddingStart;

mTop=mPaddingTop;

mRight=mWidth-mPaddingEnd;

mBottom=mHeight-mPaddingBottom;

setMeasuredDimension(mWidth,mHeight);

}

//事件拦截，防止滑动冲突，与ScrollView等可滑动控件之间；

@Override

publicbooleandispatchTouchEvent(MotionEventevent){

ViewParentparent=getParent();

switch(event.getAction()){

caseMotionEvent.ACTION_DOWN:

parent.requestDisallowInterceptTouchEvent(true);

break;

caseMotionEvent.ACTION_UP:

parent.requestDisallowInterceptTouchEvent(false);

break;

default:

break;

}

returnsuper.dispatchTouchEvent(event);

}

@Override

protectedvoidonDraw(Canvascanvas){

//画背景，如果存在的画

Drawablebg=getBackground();

if(bg!=null){

bg.draw(canvas);

}

//画背景

canvas.drawColor(Color.RED);

//画Padding以内区域的背景

mRect.set(mLeft,mTop,mRight,mBottom);

mPaint.setColor(Color.YELLOW);

canvas.drawRect(mRect,mPaint);

//TODO其他画图的操作（注意：不推荐在onDraw方法中new对象，可以使用全局变量）

super.onDraw(canvas);

}

//工具类

publicstaticintgetSizeFromMeasureSpec(intmeasureSpec,intdefaultSize){

intresult=0;

intmode=MeasureSpec.getMode(measureSpec);

intsize=MeasureSpec.getSize(measureSpec);

if(mode==MeasureSpec.EXACTLY){

result=size;

}else{

result=defaultSize;

if(mode==MeasureSpec.AT_MOST){

result=Math.min(defaultSize,size);

}

}

returnresult;

}

publicstaticfloatsp2Px(Contextcontext,floatsp){

DisplayMetricsmetrics=newDisplayMetrics();

WindowManagerwm=(WindowManager)context

.getSystemService(Context.WINDOW_SERVICE);

Displaydisplay=wm.getDefaultDisplay();

display.getMetrics(metrics);

floatpx=metrics.scaledDensity;

returnsp*px;

}

}