SpannableString spannableString=new SpannableString("d");

ImageSpan imageSpan=new ImageSpan(this, BitmapFactory.decodeResource(getResources(),R.drawable.image1));
spannableString.setSpan(imageSpan, 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

et_emotion.append(spannableString);

package fry;
import com.example.editTextDemo1.R;
import android.app.Activity;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.ImageSpan;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class Activity01 extends Activity implements OnClickListener{
 private EditText et_emotion;
 private Button bt_addEmotion;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity01);
  et_emotion=(EditText) findViewById(R.id.et_emotion);
  bt_addEmotion=(Button) findViewById(R.id.bt_addEmotion);
  bt_addEmotion.setOnClickListener(this);
 }
 @Override
 public void onClick(View arg0) {
  // TODO Auto-generated method stub
  /*
   * EditText利用SpannableString的ImageSpan实现添加表情的方法
   * 第一步：创建SpannableString对象spannableString
   * 第二步：利用SpannableString的setSpan方法添加imageSpan
   * 第三步：在EditText对象中添加spannableString
   * 
   */
  SpannableString spannableString=new SpannableString("d");
  ImageSpan imageSpan=new ImageSpan(this, BitmapFactory.decodeResource(getResources(),R.drawable.image1));
  spannableString.setSpan(imageSpan, 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
  et_emotion.append(spannableString);
 }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical" >
 <EditText
  android:id="@+id/et_emotion"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:ems="10" >
  <requestFocus />
 </EditText>
 <Button
  android:id="@+id/bt_addEmotion"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="Button" />
</LinearLayout>