android之应用程序LED(1)
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android之应用程序LED(1)
管理提醒： 本帖被 xoom 执行加亮操作(2011-08-05)
参考友善的LED程序，自己也写了个，不是用友善的libfriendlyarm-hardware.so，自己用NDK中的例子hello-jni写了个程序，已经编译成libhello-jni.so，可惜上不了图。
自己摸索了好久总算有点收获，感谢各位网友的帮忙。部门源码贴出来给大家参考！ 刚搞完就拿出来分享了，欢迎大家指正。有谁想看libfriendlyarm-hardware.so的源码的可以参考这
个。
JNI部分 用C语言实现
复制代码
1.
2. /*
3. * Copyright (C) 2009 The Android Open Source Project
4. *
5. * Licensed under the Apache License, Version 2.0 (the "License");
6. * you may not use this file except in compliance with the License.
7. * You may obtain a copy of the License at
8. *
9. * http://www.apache.org/licenses/LICENSE-2.0
10. *
11. * Unless required by applicable law or agreed to in writing, software
12. * distributed under the License is distributed on an "AS IS" BASIS,
13. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14. * See the License for the specific language governing permissions and
15. * limitations under the License.
16. *
17. */
18. #include <string.h>
19. #include <jni.h>
20. #include <fcntl.h> /*包括文件操作，如open() read() close()write()等*/
21.
22. int fd;
23.
24. /* This is a trivial JNI example where we use a native method
25. * to return a new VM String. See the corresponding Java source
26. * file located at:
27. *
28. * apps/samples/hello-jni/project/src/com/example/HelloJni/HelloJni.java
29. */
30. jstring
31. Java_com_helloworld_helloworld_stringFromJNI( JNIEnv* env,
32. jobject thiz )
33. {
34.
35. return (*env)->NewStringUTF(env, "Hello from JNI create by carlin !");
36. }
37.
38. jint Java_com_helloworld_helloworld_openled( JNIEnv* env,
39. jobject thiz )
40. {
41.
42. fd = open("/dev/leds0", O_RDONLY);
43. if (fd < 0)
44. {
45.
46. fd = open("/dev/leds", O_RDONLY);
47.
48. return 1;
49. }
50.
51. return 0;
52. }
53.
54. jint Java_com_helloworld_helloworld_setLedState( JNIEnv* env,
55. jobject thiz ,jint ledID,jint ledState)
56. {
57.
58. ioctl(fd,ledState, ledID);
59.
60. return 1;
61. }
62. jint Java_com_helloworld_helloworld_closeled( JNIEnv* env,
63. jobject thiz )
64. {
65. close(fd);
66.
67. return 1;
68. }
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APP部分即JAVA
复制代码
1. package com.helloworld;
2. import android.app.Activity;
3. import android.widget.TextView;
4. import android.os.Bundle;
5. import android.view.View;
6. import android.widget.Button;
7. import android.view.View.OnClickListener;
8. public class helloworld extends Activity {
9.
10. private Button btnLED1On;
11. private Button btnLED1Off;
12. /** Called when the activity is first created. */
13. @Override
14. public void onCreate(Bundle savedInstanceState)
15. {
16. super.onCreate(savedInstanceState);
17. setContentView(R.layout.main);
18.
19. openled();
20.
21. btnLED1On = (Button)findViewById(R.id.btnLED1On);
22. btnLED1Off = (Button)findViewById(R.id.btnLED1Off);
23.
24. btnLED1On.setOnClickListener(new View.OnClickListener()
25. {
26. public void onClick(View v) /**当按钮按下*/
27. {
28. setLedState(0,1);
29. }
30. }
31. );
32.
33. btnLED1Off.setOnClickListener(new View.OnClickListener()
34. {
35. public void onClick(View v) /**当按钮按下*/
36. {
37. setLedState(0,0);
38. }
39. }
40. );
41. }
42. /* A native method that is implemented by the
43. * 'hello-jni' native library, which is packaged
44. * with this application.
45. */
46. public native String stringFromJNI();
47. public native int openled();
48. public native int setLedState(int ledID,int ledState);
49. public native int closeled();
50. /* This is another native method declaration that is *not*
51. * implemented by 'hello-jni'. This is simply to show that
52. * you can declare as many native methods in your Java code
53. * as you want, their implementation is searched in the
54. * currently loaded native libraries only the first time
55. * you call them.
56. *
57. * Trying to call this function will result in a
58. * java.lang.UnsatisfiedLinkError exception !
59. */
60. public native String unimplementedStringFromJNI();
61. /* this is used to load the 'hello-jni' library on application
62. * startup. The library has already been unpacked into
63. * /data/data/com.example.HelloJni/lib/libhello-jni.so at
64. * installation time by the package manager.
65. */
66. static {
67. System.loadLibrary("hello-jni");
68. }
69. }
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