Android TextView 设置字体大小的方法

package com.example.yanlei.yl4;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.Spannable;
import android.text.style.AbsoluteSizeSpan;
import android.text.style.BackgroundColorSpan;
import android.text.style.StyleSpan;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
TextView edit;
Button sendBu;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

edit = (TextView) findViewById(R.id.textView);
sendBu = (Button) findViewById(R.id.button);
sendBu.setOnClickListener(new ButtonClickListener());
}
private class ButtonClickListener implements View.OnClickListener {
public void onClick(View v) {
//System.exit(0);
edit.setText("闫磊我爱你");
edit.setTextColor(Color.BLUE);

edit.setText("这是我的第一个TextView，嘿嘿", TextView.BufferType.EDITABLE);
/**
* 要设置文本的背景色，
* 必须将文本设置成BufferType.SPANNABLE,BufferType.EDITABLE
*/
Spannable sp = (Spannable) edit.getText();
//设置红色背景
sp.setSpan(new BackgroundColorSpan(Color.RED), 3, 8,
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

sp.setSpan(new StyleSpan(android.graphics.Typeface.BOLD_ITALIC),
0, 7, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); //设置斜体
sp.setSpan(new AbsoluteSizeSpan(80), 0, 2, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); //设置字体大小
edit.setText(sp);

//edit.setHeight(60);
//android.os.Process.killProcess(android.os.Process.myPid());
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}