利用canvas画text时的换行实现

private void drawText(String str,Paint pa,Canvas ca) {

float[] widths ;

float toalwidth = 0 ;

intmTextXPoint = 10 ; //text的起始点X

intmTextYPoint = 10 ; //text的起始点Y

widths = new float[50];

int index = 0;

int count = 1 ;

float height = pa.getTextSize();

pa.getTextWidths(str, widths);

for(int i=0 ;i< 50 ;i++) {

Log.e(TAG, "toalwidth =" + toalwidth);

toalwidth = toalwidth + widths[i] ;

if((( mWidth -20 ) < toalwidth) || (widths[i] == 0)) {

String text = str.substring(index, i);

Log.e(TAG, "text =" + text +" i=" +i +" index=" +index);

index = i;

if(toalwidth >( mWidth -20 ) ) {

ca.drawText(text, mTextXPoint , mTextYPoint + count *(height + 10), pa);

}else

ca.drawText(text, (mWidth - toalwidth )/2 , mTextYPoint + count *(height + 10), pa);//mWidth 是屏幕的宽度。保证居中

count ++ ;

toalwidth = 0 ;

if(widths[i] == 0)

return ;

}

}

}