Android LoaderManager AsyncTaskLoader cancelLoad不deliverResult，Java

末蓝、 2023-09-25 18:44 37阅读 0赞

import androidx.annotation.NonNull;
    import androidx.annotation.Nullable;
    import androidx.appcompat.app.AppCompatActivity;
    import androidx.loader.app.LoaderManager;
    import androidx.loader.content.AsyncTaskLoader;
    import androidx.loader.content.Loader;
    
    import android.content.Context;
    import android.os.Bundle;
    import android.os.SystemClock;
    import android.util.Log;
    import android.view.View;
    
    
    public class MainActivity extends AppCompatActivity {
        private static String TAG = "fly";
    
        private LoaderManager loaderManager;
    
        private static int index = 0;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            findViewById(R.id.start).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    index++;
    
                    Log.d("fly", "--" + index + "--");
                    Log.d("fly", "开始新任务" + index);
                    loaderManager.getLoader(2023).forceLoad();
                }
            });
    
            findViewById(R.id.cancel).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Log.d("fly", "放弃加载" + index);
                    loaderManager.getLoader(2023).cancelLoad(); //deliverResult不执行
                }
            });
    
            setupLoader();
        }
    
        private void setupLoader() {
            loaderManager = LoaderManager.getInstance(this);
            loaderManager.initLoader(2023, new Bundle(), loaderCallbacks);
        }
    
        private LoaderManager.LoaderCallbacks loaderCallbacks = new LoaderManager.LoaderCallbacks<String>() {
            @NonNull
            @Override
            public MyTask onCreateLoader(int id, @Nullable Bundle args) {
                Log.d(TAG, "onCreateLoader- id - " + id);
                MyTask loader = new MyTask(getApplicationContext());
                return loader;
            }
    
            @Override
            public void onLoadFinished(@NonNull Loader<String> loader, String data) {
                Log.d(TAG, "onLoadFinished- " + loader.getId() + " " + data);
            }
    
            @Override
            public void onLoaderReset(@NonNull Loader loader) {
    
            }
        };
    
        private static class MyTask extends AsyncTaskLoader<String> {
    
            public MyTask(@NonNull Context context) {
                super(context);
            }
    
            @Nullable
            @Override
            public String loadInBackground() {
                Log.d("fly", index + " loadInBackground 开始@" + Thread.currentThread().getId());
                SystemClock.sleep(5000);
                Log.d("fly", index + " loadInBackground 结束@" + Thread.currentThread().getId());
                return index + "";
            }
    
            @Override
            public void deliverResult(@Nullable String data) {
                super.deliverResult(data);
                Log.d("fly", "deliverResult -> " + data + " 结束");
            }
    
            @Override
            protected void onStopLoading() { //绑定的Activity生命周期自动执行，切入后台
                super.onStopLoading();
                Log.d("fly", "onStopLoading");
            }
    
    
            @Override
            protected void onStartLoading() { //绑定的Activity生命周期自动执行，切入前台
                super.onStartLoading();
            }
    
    
            @Override
            public void onCanceled(@Nullable String data) {
                super.onCanceled(data);
                Log.d("fly", "onCanceled @" + Thread.currentThread().getId());
            }
        }
    
        @Override
        protected void onStart() {
            super.onStart();
            Log.d(TAG, "---");
            Log.d(TAG, "onStart");
        }
    
        @Override
        protected void onResume() {
            super.onResume();
            Log.d(TAG, "onResume");
        }
    
        @Override
        protected void onStop() {
            super.onStop();
            Log.d(TAG, "onStop");
        }
    }

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[android ，LoaderManager.LoaderCallbacks与AsyncTaskLoader， Java（2）\_zhangphil的博客-CSDN博客android LoaderManager与AsyncTaskLoader,java（1）\_zhangphil的博客-CSDN博客。android LoaderManager与AsyncTaskLoader,java（1）![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/129625669][android _LoaderManager.LoaderCallbacks_AsyncTaskLoader_ Java_2_zhangphil_-CSDN_android LoaderManager_AsyncTaskLoader_java_1_zhangphil_-CSDN_android LoaderManager_AsyncTaskLoader_java_1_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_129625669]

[android LoaderManager与AsyncTaskLoader,java（1）\_zhangphil的博客-CSDN博客android LoaderManager与AsyncTaskLoader,java（1）![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/129622307][android LoaderManager_AsyncTaskLoader_java_1_zhangphil_-CSDN_android LoaderManager_AsyncTaskLoader_java_1_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_129622307]

[https://zhangphil.blog.csdn.net/article/details/129582389![icon-default.png?t=N2N8][icon-default.png_t_N2N8]https://zhangphil.blog.csdn.net/article/details/129582389][https_zhangphil.blog.csdn.net_article_details_129582389_icon-default.png_t_N2N8_icon-default.png_t_N2N8_https_zhangphil.blog.csdn.net_article_details_129582389]

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