Android studio 简单的多线程
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
<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>