Android------- jni返回结构体 android

1.创建工程，添加jni

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2. main.cpp

#include struct test_data { char name[256]; intnum; double average; }; extern "C" { JNIEXPORT jobjectJNICALL Java_com_re_struct_MainActivity_call(JNIEnv * env, jobject obj, jobject classobj); }; JNIEXPORT jobjectJNICALL Java_com_re_struct_MainActivity_call(JNIEnv * env, jobject obj, jobject classobj) { jclass objectClass = env->FindClass("com/re/struct/test_data"); jfieldID name = env->GetFieldID(objectClass, "name", "Ljava/lang/String; "); jfieldID num = env->GetFieldID(objectClass, "num", "I"); jfieldID average = env->GetFieldID(objectClass, "average", "D"); env->SetObjectField(classobj, name, env->NewStringUTF("hello world")); env->SetIntField(classobj, num, 10); env->SetDoubleField(classobj, average, 2.5); return classobj; }

3. test_data.java
【Android------- jni返回结构体】

package com.re.struct; public class test_data { public String name; public intnum; public double average; }

4. MainActivity.java

package com.re.struct; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.Menu; public class MainActivity extends Activity { static{ System.loadLibrary("main"); } private native test_data call(test_data data); private test_data data = https://www.it610.com/article/new test_data(); private static final String TAG="######"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); data = https://www.it610.com/article/call(data); Log.e(TAG,"name:" + data.name); Log.e(TAG, "num:" + data.num); Log.e(TAG, "average:" + data.average); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; }}

5. 效果：

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6. 补充：

Java类型	符号
boolean	Z
byte	B
char	C
short	S
int	I
long	L
float	F
double	D
void	V
objects对象	Lfully-qualified-class-name; L类名;
Arrays数组	[array-type [数组类型
methods方法	(argument-types)return-type(参数类型)返回类型