title: 回調callback

參考：

JAVA回調機制(CallBack)詳解
一個經典例子讓你徹徹底底理解java回調機制

1.新建一個類，聲明接口：

public interface GetCodeCallback {    
      void GetCodeCallback(String result);
}

2.實現(xiàn)接口

public abstract class AbstractBlocklyActivity extends AppCompatActivity  implements GetCodeCallback{

@Override
public void GetCodeCallback(String result) {    
       System.out.println("返回來的草泥馬--->" + result);
}

在oncreate 中使用

LoggingCodeGeneratorCallback lc = new LoggingCodeGeneratorCallback(this,"我也不知道");
lc.executeMessage(this);

public class LoggingCodeGeneratorCallback implements CodeGenerationRequest.CodeGeneratorCallback {
    private static GetCodeCallback callbackd; //使用靜態(tài)，不然會是空指針異常。
    protected final String mTag;
    protected final Context mContext;

    public LoggingCodeGeneratorCallback(Context context, String loggingTag) {
        mTag = loggingTag;
        mContext = context;
    }

    public void executeMessage(GetCodeCallback callBack) {
        System.out.println("小王問的問題--->");

        this.callbackd = callBack;
    }

    @Override
    public void onFinishCodeGeneration(String generatedCode) {
        // Sample callback.
        if (generatedCode.isEmpty()) {
            Toast.makeText(mContext,
                "Something went wrong with code generation.", Toast.LENGTH_LONG)
                 .show();
        } else {
            Log.d(mTag, "code: " + generatedCode);
            //            Toast.makeText(mContext, generatedCode, Toast.LENGTH_LONG).show();
            callbackd.GetCodeCallback(generatedCode);
        }
    }
}