首先获取一个安卓权限
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>
创建一个GifInfoHandle 类
并且调用c++接口
package com.example.ndkdemo; import android.graphics.Bitmap; public class GifInfoHandle { private volatile long gifInfoPtr; static { System.loadLibrary("android_gif"); } public GifInfoHandle(String path) { gifInfoPtr=openFile(path); } public long renderFrame(Bitmap bitmap) { return renderFrame(gifInfoPtr,bitmap); } public synchronized int getwidth() { return getwidth(gifInfoPtr); } public synchronized int getHeight() { return getheight(gifInfoPtr); } //调用 native private native long openFile(String path); //打开文件路径 private native long renderFrame( long gifInfoPtr, Bitmap bitmap); //获取帧率 private native int getwidth(long gifInfoPtr); //获取宽度 private native int getheight(long gifInfoPtr); //获取高度 }
通过配置c++代码获取回调接口
jint getwidth(GifInfo *info){ return info->originalWidth; } jint getHeight(GifInfo *info){ return info->originalHeight; } JNIEXPORT jlong JNICALL Java_com_example_ndkdemo_GifInfoHandle_openFile(JNIEnv *env, jobject thiz, jstring path) { // TODO: implement openFile() return openFile(env,path); } JNIEXPORT jlong JNICALL Java_com_example_ndkdemo_GifInfoHandle_renderFrame(JNIEnv *env, jobject thiz, jlong gif_info_ptr, jobject bitmap) { // TODO: implement renderFrame() return renderFrame(env,gif_info_ptr,bitmap); } JNIEXPORT jint JNICALL Java_com_example_ndkdemo_GifInfoHandle_getwidth(JNIEnv *env, jobject thiz, jlong gif_info_ptr) { // TODO: implement getwidth() getwidth(gif_info_ptr); } JNIEXPORT jint JNICALL Java_com_example_ndkdemo_GifInfoHandle_getheight(JNIEnv *env, jobject thiz, jlong gif_info_ptr) { // TODO: implement getheight() getHeight(gif_info_ptr); }
这里用的动态库在这个网站获取 https://sourceforge.net/projects/giflib/
通过主页面获取回调方法
package com.example.ndkdemo; import androidx.annotation.NonNull; import androidx.appcompat.app.AppCompatActivity; import android.graphics.Bitmap; import android.os.Bundle; import android.os.Environment; import android.os.Handler; import android.os.Message; import android.util.Log; import android.widget.ImageView; import android.widget.TextView; import java.io.File; public class MainActivity extends AppCompatActivity { // Used to load the ‘native-lib‘ library on application startup. private ImageView imageView; private String path = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "ds.gif"; private Bitmap bitmap; private GifInfoHandle infoHandle; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Log.e("TAG", "onCreate: "+path ); imageView=findViewById(R.id.image); infoHandle=new GifInfoHandle(path); int width=infoHandle.getwidth(); int height=infoHandle.getHeight(); bitmap =Bitmap.createBitmap(width,height,Bitmap.Config.ARGB_8888); imageView.setImageBitmap(bitmap); long nextFrameTime=infoHandle.renderFrame(bitmap); infoHandle.renderFrame(bitmap); //循环绘制 handler.sendEmptyMessageDelayed(1,nextFrameTime); } Handler handler=new Handler(){ @Override public void handleMessage(@NonNull Message msg) { super.handleMessage(msg); long nextFrameTime =infoHandle.renderFrame(bitmap); imageView.setImageBitmap(bitmap); handler.sendEmptyMessageDelayed(1,nextFrameTime); } }; }
下面是这次的源码
链接:https://pan.baidu.com/s/133c9Fk7BXwPrugP5wCrv5A
提取码:5wa1
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