Android studio 简单的多线程
16lz
2021-01-23
运行效果
文件结构
主要代码
MainActivity
package cn.edu.sicnu.threaddemo;import android.os.AsyncTask;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.ProgressBar;import android.widget.TextView;import java.lang.ref.WeakReference;import java.security.PublicKey;public class MainActivity extends AppCompatActivity { private static final String TAG = "MainActivity"; TextView textView; ProgressBar progressBar; MyAsyncTask myAsyncTask; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); textView = findViewById(R.id.textView); progressBar = findViewById(R.id.progressBar); } static class MyAsyncTask extends AsyncTask{ WeakReference weakReference; public MyAsyncTask(MainActivity activity){ weakReference = new WeakReference(activity); } @Override protected void onPreExecute() { super.onPreExecute(); MainActivity activity = weakReference.get(); if (activity!=null) activity.progressBar.setProgress(0); Log.d(TAG, "onPreExecute: "); } @Override protected Integer doInBackground(Integer... integers) { int sum = 0; for(int i = 1; i < 100; i++) { try { Log.d(TAG, "doInBackground: " + Thread.currentThread().getName()); Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } sum += i; publishProgress(i); if(isCancelled()) break; } return -1; } @Override protected void onProgressUpdate(Integer... values) { super.onProgressUpdate(values); Log.d(TAG, "onProgressUpdate: "); MainActivity activity = weakReference.get(); if (activity!=null) { activity.textView.setText("progress"+values[0]); activity.progressBar.setProgress(values[0]); } } @Override protected void onCancelled() { super.onCancelled(); MainActivity activity = weakReference.get(); if (activity!=null) activity.textView.setText("cancel!!!!"); } @Override protected void onPostExecute(Integer integer) { super.onPostExecute(integer); Log.d(TAG, "onPostExecute: "); MainActivity activity = weakReference.get(); if (activity!=null) { activity.textView.setText("congratulation!!!finished"); activity.progressBar.setProgress(0); } } } public void calculate(View v) { myAsyncTask = new MyAsyncTask(this); myAsyncTask.execute(0); } public void stop(View v){ myAsyncTask.cancel(true); }// private MyHandler handler = new MyHandler(this);// private Handler handler = new Handler() {// @Override// public void handleMessage(Message msg) {// super.handleMessage(msg);//// switch (msg.what){// case 0:// textView.setText("progress:"+msg.arg1);//// break;// case 1:// textView.setText("congratulation!!!finished"+msg.what);//// break;// }// Log.d(TAG, "handleMessage: "+Thread.currentThread().getName());// }// };//// static class MyHandler extends Handler{//// WeakReference weakReference; //// public MyHandler(MainActivity activity){// this.weakReference = new WeakReference(activity); // }////// @Override// public void handleMessage(Message msg) {// super.handleMessage(msg);//// MainActivity activity = weakReference.get();// if (activity == null) return;;//// switch (msg.what){// case 0:// activity.textView.setText("progress:"+msg.arg1);//// break;// case 1:// activity.textView.setText("congratulation!!!finished"+msg.what);//// break;// }// Log.d(TAG, "handleMessage: "+Thread.currentThread().getName());// }// }//// new Thread(new Runnable() {// @Override// public void run() {// int sum = 0;// for(int i = 1; i < 100; i++){// try {// Log.d(TAG, "run: "+Thread.currentThread().getName());// Thread.sleep(100);// } catch (InterruptedException e) {// e.printStackTrace();// }// sum += i;// final int j = i;// handler.post(new Runnable() {// @Override// public void run() {// textView.setText("progress:"+j);// }// });//// Message msg = handler.obtainMessage();//// msg.what = 0;//// msg.arg1 = i;//// handler.sendMessage(msg);// }//// handler.post(new Runnable() {// @Override// public void run() {// textView.setText("congratulation!!!finished");// }// });//////// Message msg = handler.obtainMessage();//// msg.what = 1;//// handler.sendMessage(msg);// }// }).start();//////// }} activity_main.xml
<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="cn.edu.sicnu.threaddemo.MainActivity" tools:layout_editor_absoluteY="81dp"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="26dp" android:text="Hello World!" app:layout_constraintBottom_toTopOf="@+id/button2" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" /> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="27dp" android:layout_marginEnd="53dp" android:onClick="calculate" android:text="start" app:layout_constraintBottom_toTopOf="@+id/progressBar" app:layout_constraintEnd_toEndOf="@+id/textView" /> <ProgressBar android:id="@+id/progressBar" style="?android:attr/progressBarStyleHorizontal" android:layout_width="0dp" android:layout_height="40dp" android:layout_marginBottom="105dp" android:layout_marginEnd="11dp" android:layout_marginStart="11dp" android:max="100" android:progress="0" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginEnd="66dp" android:layout_marginStart="64dp" android:onClick="stop" android:text="stop" app:layout_constraintBaseline_toBaselineOf="@+id/button" app:layout_constraintEnd_toEndOf="@+id/progressBar" app:layout_constraintStart_toStartOf="@+id/textView" />android.support.constraint.ConstraintLayout>更多相关文章
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