通过自定义TextView非常简单的实现右上角数字气泡提示
package com.xuan.forens.actionhttp;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.widget.TextView;
/**
* Created by forens.xuan on 2017/7/9 13:48
* e-mail: 1129305620@qq.com
* des:
*/
public class MsgTextView extends TextView {
private Paint mPaint,textPaint;
private int msgCount;
//原点偏移量，半径
private float x,y,f=10,r=30;
//是否已经初始化过
private boolean init=false;
public MsgTextView(Context context) {
super(context);
initMsgTextView();
}
public MsgTextView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
initMsgTextView();
}
public MsgTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initMsgTextView();
}
private void initMsgTextView(){
setPadding(0, (int) (r-f),0,0);
initPaint();
}
public void setMsg(int count){
msgCount=count;
postInvalidate();
}
private void initPaint(){
if (mPaint == null) {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setColor(Color.parseColor("#FE0264"));
textPaint=new Paint();
textPaint.setColor(Color.parseColor("#FFFFFF"));
textPaint.setTextAlign(Paint.Align.CENTER);
textPaint.setTextSize(r);
textPaint.setAntiAlias(true);
}
}
private void drawValue(Canvas canvas){
if(msgCount>0) {
canvas.drawCircle(x, y, r, mPaint);
Paint.FontMetricsInt fontMetrics = textPaint.getFontMetricsInt();
int baseline = (int) (((r * 2) - fontMetrics.bottom + fontMetrics.top) / 2 - fontMetrics.top);
canvas.drawText(String.valueOf(msgCount), x, baseline, textPaint);
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(!init){
Drawable[] n = getCompoundDrawables();
Drawable top = n[1];
if (top != null) {
int w = top.getBounds().width();
x=(getWidth() / 2 + w / 2) - 10;
y=getPaddingTop()+10;
init=true;
}
}
drawValue(canvas);
}
}
截图看到，下面那个气泡显示不全，这里要注意的是使用时要根据实际情况调整Padding值使它能完整显示出来
