开发日志

package com.li.ying;  
  
import android.graphics.Bitmap;  
import android.graphics.BitmapFactory;  
import android.os.Bundle;  
import androidx.annotation.NonNull;  
import androidx.annotation.Nullable;  
import io.flutter.embedding.android.FlutterActivity;  
import io.flutter.embedding.engine.FlutterEngine;  
import io.flutter.plugin.common.MethodCall;  
import io.flutter.plugin.common.MethodChannel;  
import android.renderscript.*;  
  
import java.io.File;  
import java.io.FileOutputStream;  
import java.io.IOException;  
  
public class MainActivity extends FlutterActivity {  
  private static final String CHANNEL = "image_processing";  
  
  @Override  
  public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {  
    super.configureFlutterEngine(flutterEngine);  
    new MethodChannel(flutterEngine.getDartExecutor().getBinaryMessenger(), CHANNEL)  
      .setMethodCallHandler(  
        (call, result) -> {  
          if (call.method.equals("blurImage")) {  
            String imagePath = call.argument("imagePath");  
            int radius = call.argument("radius");  
            try {  
              result.success(blurImage(imagePath, radius));  
            } catch (IOException e) {  
              throw new RuntimeException(e);  
            }  
          } else {  
            result.notImplemented();  
          }  
        }  
      );  
  }  
  
  private String blurImage(String imagePath, int radius) throws IOException {  
    Bitmap bitmap = BitmapFactory.decodeFile(imagePath);  
    RenderScript rs = RenderScript.create(this);  
    Allocation input = Allocation.createFromBitmap(rs, bitmap);  
    Allocation output = Allocation.createTyped(rs, input.getType());  
    ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));  
  
    // 多次应用高斯模糊  
    for (int i = 0; i < 5; i++) {  
      script.setRadius(radius);  
      script.setInput(input);  
      script.forEach(output);  
      output.copyTo(bitmap);  
      input.copyFrom(bitmap);  
    }  
  
    rs.destroy();  
  
    File outputDir = getCacheDir();  
    File outputFile = File.createTempFile("blurred_", ".png", outputDir);  
    FileOutputStream out = new FileOutputStream(outputFile);  
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);  
    out.close();  
  
    return outputFile.getAbsolutePath();  
  }  
  
}