编译源代码时出现'ndk-build'错误

Question

我正在学习以下教程： http://taylorpeer.com/hello-world-cpp-android-ndk/

当我在终端运行ndk-build时，出现以下错误：

Compile++ thumb  : hello-jni <= hello-jni.cpp
jni/hello-jni.cpp:4:5: error: stray '\342' in program
jni/hello-jni.cpp:4:5: error: stray '\200' in program
jni/hello-jni.cpp:4:5: error: stray '\234' in program
jni/hello-jni.cpp:4:5: error: stray '\342' in program
jni/hello-jni.cpp:4:5: error: stray '\200' in program
jni/hello-jni.cpp:4:5: error: stray '\235' in program
jni/hello-jni.cpp:9:17: error: stray '\342' in program
jni/hello-jni.cpp:9:17: error: stray '\200' in program
jni/hello-jni.cpp:9:17: error: stray '\234' in program
jni/hello-jni.cpp:9:17: error: stray '\342' in program
jni/hello-jni.cpp:9:17: error: stray '\200' in program
jni/hello-jni.cpp:9:17: error: stray '\235' in program
jni/hello-jni.cpp:4:15: error: 'C' does not name a type
make: *** [obj/local/armeabi/objs/hello-jni/hello-jni.o] Error 1

以下是我的文件列表：

在 src 文件夹中找到的 Java 文件

package com.example;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

    public class Hellojnicpp extends Activity {
          /** Called when the activity is first created. */
          @Override
          public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                /** Create a TextView and set it to display
                * text loaded from a native method.
                */
                TextView tv = new TextView(this);
                tv.setText(stringFromJNI());
                setContentView(tv);
          }
          /** A native method that is implemented by the
          * ‘hello-jni’ native library, which is packaged
          * with this application.
          */
          public native String stringFromJNI();
          /** Load the native library where the native method
          * is stored.
          */
          static {
                System.loadLibrary("hello-jni");
          }
    }

Android.mk 文件

LOCAL_PATH := $(call my-dir)


include $(CLEAR_VARS)
LOCAL_LDLIBS    := -llog

LOCAL_MODULE := hello-jni
LOCAL_SRC_FILES := hello-jni.cpp

include $(BUILD_SHARED_LIBRARY)

.cpp 文件

#include <string.h>
#include <jni.h>

extern “C” {
    JNIEXPORT jstring JNICALL
    Java_com_example_Hellojnicpp_stringFromJNI
    (JNIEnv *env, jobject obj)
    {
        return env->NewStringUTF(“Hello from C++ over JNI!”);
    }
}

如何修复错误？

将“C”更改为“C”后，我现在收到以下错误：

Compile++ thumb  : hello-jni <= hello-jni.cpp
jni/hello-jni.cpp:9:17: error: stray '\342' in program
jni/hello-jni.cpp:9:17: error: stray '\200' in program
jni/hello-jni.cpp:9:17: error: stray '\234' in program
jni/hello-jni.cpp:9:17: error: stray '\342' in program
jni/hello-jni.cpp:9:17: error: stray '\200' in program
jni/hello-jni.cpp:9:17: error: stray '\235' in program
jni/hello-jni.cpp: In function '_jstring* Java_com_example_Hellojnicpp_stringFromJNI(JNIEnv*, jobject)':
jni/hello-jni.cpp:9:45: error: 'Hello' was not declared in this scope
make: *** [obj/local/armeabi/objs/hello-jni/hello-jni.o] Error 1

Answer 1

检查你的

""

：

#include <string.h>
#include <jni.h>

extern "C" {
    JNIEXPORT jstring JNICALL
    Java_com_example_Hellojnicpp_stringFromJNI
    (JNIEnv *env, jobject obj)
    {
        return env->NewStringUTF("Hello from C++ over JNI!");
    }
}

Answer 2

extern “C”

应该是

extern "C"

即没有“卷曲”引号。确保您的文本编辑器不会为您“美化”您的直引号。