我将创建一个Android应用程序,执行加法,减法,乘法,除法等算术功能。
我知道这是一个简单的应用程序,但为了使它有点复杂,我用C编写它,它被称为“ArithmeticOperations.c”。
现在我想将这个.c文件作为库包含到我的Android项目中。
我试过了:
如何将此.c文件作为库提供给Android项目?
first.c
int add(int x, int y)
{
return x+y;
}
int sub(int x, int y)
{
return x-y;
}
int mul(int x, int y)
{
return x*y;
}
int div(int x, int y)
{
return x/y;
}
**second.c**
#include "first.h"
#include <jni.h>
jint
Java_bri_ndk_sample_ArithmeticOperations_add( JNIEnv* env,
jobject this,
jint x,
jint y )
{
return add(x, y);
}
jint
Java_bri_ndk_sample_ArithmeticOperations_sub( JNIEnv* env,
jobject this,
jint x,
jint y )
{
return sub(x, y);
}
jint
Java_bri_ndk_sample_ArithmeticOperations_mul( JNIEnv* env,
jobject this,
jint x,
jint y )
{
return mul(x, y);
}
jint
Java_bri_ndk_sample_ArithmeticOperations_div( JNIEnv* env,
jobject this,
jint x,
jint y )
{
return div(x, y);
}
first.h
extern int add(int x, int y);
extern int mul(int x, int y);
extern int sub(int x, int y);
extern int div(int x, int y);
Android活动
package bri.sample;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class SampleTestActivity extends Activity {
/** Called when the activity is first created. */
static{
try{
System.loadLibrary("twolib-second");
}catch (Exception e){
e.printStackTrace();
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final EditText xVal = (EditText)findViewById(R.id.editText1);
final EditText yVal = (EditText)findViewById(R.id.editText2);
final TextView result = (TextView)findViewById(R.id.textView1);
//final Arithmetic al = new Arithmetic();
Button b1 = (Button) findViewById(R.id.button1);
b1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int x = Integer.parseInt(xVal.getText().toString());
int y = Integer.parseInt(yVal.getText().toString());
Integer z = add(x, y);
result.setText(z.toString());
}
});
Button sub = (Button) findViewById(R.id.button2);
sub.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int x = Integer.parseInt(xVal.getText().toString());
int y = Integer.parseInt(yVal.getText().toString());
Integer z = sub(x, y);
result.setText(z.toString());
}
});
Button mul = (Button) findViewById(R.id.button3);
mul.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int x = Integer.parseInt(xVal.getText().toString());
int y = Integer.parseInt(yVal.getText().toString());
Integer z = mul(x, y);
result.setText(z.toString());
}
});
Button div = (Button) findViewById(R.id.button4);
div.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int x = Integer.parseInt(xVal.getText().toString());
int y = Integer.parseInt(yVal.getText().toString());
Integer z = div(x, y);
result.setText(z.toString());
}
});
}
public native int add(int x, int y);
public native int sub(int x, int y);
public native int mul(int x, int y);
public native int div(int x, int y);
}
现在我希望这个C文件作为Android的库
这也可以视为
我分别使用android NDK创建了一个.so文件,并包含在测试应用程序的libs / armeabi文件夹中;它显示了不满意的链接错误异常
你使用system.loadLibrary()加载了库吗?你应该在你班级的“静态”部分内进行,例如参见this。
将共享库(.so文件)放在libs / armeabi文件夹下并正确调用System.loadLibrary(...)应该可以正常工作。无需分发来源。
验证.so文件是否真的在.apk文件中(它是一个zip文件),并验证您是否使用正确的名称调用loadLibrary。