android中用GLSurfaceview和opengl es2.0显示图片，图片无法正常显示

想用GLSurfaceView配合OPENGL es2.0编程实现把图片显示到手机界面中，照着网上的例子，自己在eclipse中敲了一遍，但是就是无法显示出图片（试过128*128的png和bmp），就显示出一个白色的界面。
网上找了下，没找到原因，求大神给看看。

代码如下：

package com.example.glsurfaceview_drawpicture;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;
import java.security.spec.MGF1ParameterSpec;
import java.util.TooManyListenersException;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.opengl.GLSurfaceView.Renderer;
import android.opengl.GLUtils;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;

public class MainActivity extends Activity
implements Renderer{

final float[] vertexCoord = {
-0.5f,0.5f,0.0f,
-0.5f,-0.5f,0.0f,
0.5f,-0.5f,0.0f,
0.5f,0.5f,0.0f
};

final float[] textureCoord ={
1.0f,0.0f,
0.0f,0.0f,
1.0f,0.0f,
1.0f,1.0f
};

final short[] mdrawCoord = {0,1,2,0,2,3};

final String sVertexShader=
"uniform mat4 u_MVPMatrix;" +
"attribute vec4 a_position;"
+ "attribute vec2 a_texturecoord;"
+ "varying vec2 v_texturecoord;"
+ "void main()"
+ "{"
+ "gl_Position = a_position;"
+ "v_texturecoord = a_texturecoord;"
+ "}";

final String sFragmentShader =
"precision mediump float;"
+ "varying vec2 v_texturecoord;"
+ "uniform sampler2D u_samplerTexture;"
+ "void main()"
+ "{"
+ "gl_FragColor = texture2D(u_samplerTexture,v_texturecoord);"
+ "}";

GLSurfaceView mSurfaceView;
public int mprogramHandle;
public int mvertexShaderHandle;
public int mfragmentShaderHandle;

public int mAPositionIndex;
public int mATextureCoordIndex;
public int mUniformTextureIndex;

public FloatBuffer fb_position;
public FloatBuffer fb_texturecoord;
public ShortBuffer fb_drawCoord;

public int textureId;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

mSurfaceView = new GLSurfaceView(this);
mSurfaceView.setEGLContextClientVersion(2);
mSurfaceView.setRenderer(this);
setContentView(mSurfaceView);
}

public int createShapeHandle(int handle,String shadercode,int type)
{
//创建渲染器容器
handle = GLES20.glCreateShader(type);
if(handle!=0){
//将渲染器代码放入容器中
GLES20.glShaderSource(handle, shadercode);
//编译
GLES20.glCompileShader(handle);

int status[] = new int[1];
//获取编译结果
GLES20.glGetShaderiv(handle, GLES20.GL_COMPILE_STATUS, status, 0);
if(status[0] == 0){
String ss = GLES20.glGetShaderInfoLog(handle);
Log.e("qcong_test",ss);
GLES20.glDeleteShader(handle);
handle =0;
}
}

if(handle == 0){
if(type == GLES20.GL_VERTEX_SHADER){
throw new RuntimeException("Fail to create Vertex Shader!");
}else if(type == GLES20.GL_FRAGMENT_SHADER){
throw new RuntimeException("Fail to create Fragement Shader!");
}
}else{
if(type == GLES20.GL_VERTEX_SHADER){
Log.e("qcong_test","Create vertex shader successful!");
}else if(type == GLES20.GL_FRAGMENT_SHADER){
Log.e("qcong_test","Create fragment shader successful!");
}
}

return handle;
}

public void createProgram()
{
//创建程序
mprogramHandle = GLES20.glCreateProgram();

if(mprogramHandle != 0){
//将渲染器容器绑定到程序中
GLES20.glAttachShader(mprogramHandle, mvertexShaderHandle);
GLES20.glAttachShader(mprogramHandle,mfragmentShaderHandle);
//链接程序
GLES20.glLinkProgram(mprogramHandle);

int status[] = new int[1];
//获取链接结果
GLES20.glGetProgramiv(mprogramHandle, GLES20.GL_LINK_STATUS, status, 0);
if(status[0] == 0){
GLES20.glDeleteProgram(mprogramHandle);
mprogramHandle =0;
}
}

if(mprogramHandle == 0){
throw new RuntimeException("Fail to create program!");
}else{
Log.e("qcong_test","Create program succussful!");
}
}

@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {

//激活2D纹理
GLES20.glEnable(GLES20.GL_TEXTURE_2D); 

//创建缓存，存放数据
fb_position = ByteBuffer.allocateDirect(vertexCoord.length * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer();
fb_position.put(vertexCoord).position(0);
fb_texturecoord = ByteBuffer.allocateDirect(textureCoord.length * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer();
fb_texturecoord.put(textureCoord).position(0);

fb_drawCoord = ByteBuffer.allocateDirect(mdrawCoord.length * 2)
 .order(ByteOrder.nativeOrder())
 .asShortBuffer();
fb_drawCoord.put(mdrawCoord).position(0);

//建立渲染器容器
mvertexShaderHandle   = createShapeHandle(mvertexShaderHandle,sVertexShader,GLES20.GL_VERTEX_SHADER);
mfragmentShaderHandle = createShapeHandle(mfragmentShaderHandle,sFragmentShader,GLES20.GL_FRAGMENT_SHADER);

if(mvertexShaderHandle == 0 || mfragmentShaderHandle == 0)
return;

//创建程序
createProgram();

//获取渲染器中变量的句柄
mAPositionIndex = GLES20.glGetAttribLocation(mprogramHandle, "a_position");
mATextureCoordIndex = GLES20.glGetAttribLocation(mprogramHandle, "a_textureCoord");
mUniformTextureIndex = GLES20.glGetUniformLocation(mprogramHandle, "u_samplerTexture");

GLES20.glUseProgram(mprogramHandle);
//启用顶点属性数组
GLES20.glEnableVertexAttribArray(mAPositionIndex);
GLES20.glEnableVertexAttribArray(mATextureCoordIndex);
//设置纹理采样器的值
GLES20.glUniform1i(mUniformTextureIndex, 0); 
//绑定纹理单元（为上面的采样器绑定）
GLES20.glActiveTexture(GLES20.GL_TEXTURE0 + 0);

textureId = loadTexture();
}

@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
}

@Override
public void onDrawFrame(GL10 gl) 
{
GLES20.glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId); 

GLES20.glVertexAttribPointer(mAPositionIndex, 3, GLES20.GL_FLOAT, false, 12, fb_position);
GLES20.glVertexAttribPointer(mATextureCoordIndex, 2, GLES20.GL_FLOAT, false, 8, fb_texturecoord);
GLES20.glDrawElements(GLES20.GL_TRIANGLES, mdrawCoord.length,GLES20.GL_UNSIGNED_SHORT,fb_drawCoord);
}

public int loadTexture()
{
int[] texture_ID = new int[1];

//创建纹理,得到ID
GLES20.glGenTextures(1, texture_ID, 0);
if(texture_ID[0]!=0){
Bitmap bitmap;
try {
bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic129);//BitmapFactory.decodeStream(getAssets().open("ic128.png")); //BitmapFactory.decodeFile(path);
//将生成的纹理ID绑定到指定的纹理上
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture_ID[0]);
//设置纹理属性
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, 
GLES20.GL_NEAREST); 
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, 
GLES20.GL_NEAREST); 
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, 
GLES20.GL_CLAMP_TO_EDGE); 
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, 
GLES20.GL_CLAMP_TO_EDGE);

//绑定纹理数据,传入指定图片
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
bitmap.recycle();
} catch (Exception e) {
e.printStackTrace();
}
}
return texture_ID[0];
}

@Override
protected void onResume() {
super.onResume();
mSurfaceView.onResume();
}

@Override
protected void onPause() {
super.onPause();
mSurfaceView.onPause();
}
}