[英]How to properly use the Android OnTouchListener and OnTouch function?
[英]How do I use a while loop with an onTouch function? (Android)
好吧,我一直在查找答案,但沒有一個對我有用。 我有一個按鈕,當它是HELD DOWN時,假設繼續在屏幕上移動圖像。 但出於某種原因,當我點擊按鈕時它只會讓我的點燃。 我認為線程是問題的一部分,但我不確定。 這是代碼:
package com.evilsea.darkages;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Color;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class MainActivity extends Activity implements OnTouchListener, Runnable {
ImageView leftImageButton;
boolean leftButtonDown = false;
ImageView knight;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Thread thread1 = new Thread(this);
thread1.start();
this.run();
}
public void addListenerOnLeftButton() {
leftImageButton = (ImageView) findViewById(R.id.left_button);
leftImageButton.setOnTouchListener(leftButtonlistener);
knight = (ImageView) findViewById(R.id.knight_image);
}
OnTouchListener leftButtonlistener = new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
leftButtonDown = true;
try {
while(leftButtonDown) {
Thread.sleep(10);
moveLeft(5);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
break;
case MotionEvent.ACTION_UP:
leftButtonDown = false;
break;
}
return false;
}
};
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
return false;
}
@Override
public void run() {
addListenerOnLeftButton();
}
public void moveLeft(int speed) throws InterruptedException {
knight.setLeft(knight.getLeft() -speed);
}
}
順便說一句,我剛剛開始使用android,所以如果這是一個明顯的問題,我很抱歉。 謝謝! 非常感激。
首先,你正在進行UI線程休眠,這就是你的UI被凍結的原因。在這里,我創建了一個異步任務,我正在睡覺后台線程並在主線程上運行UI更新,如下面doInBackground方法中所示。這是你的解決方案 - :
public class MainActivity extends Activity {
private ImageView leftImageButton;
private boolean leftButtonDown = false;
private ImageView knight;
private AsyncTask asyncTask = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
leftImageButton = (ImageView) findViewById(R.id.imageView2);
knight = (ImageView) findViewById(R.id.imageView1);
leftImageButton.setOnTouchListener(new LeftImageListener());
}
public void startTask() {
asyncTask = new AsyncTask<Void, Void, Void>() {
@Override
protected Void doInBackground(Void... params) {
if (leftButtonDown) {
while (leftButtonDown) {
try {
Thread.sleep(10);
runOnUiThread(new Runnable() {
@Override
public void run() {
try {
moveLeft(5);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
return null;
}
}.execute();
}
public void moveLeft(int speed) throws InterruptedException {
knight.setLeft(knight.getLeft() - speed);
}
public class LeftImageListener implements OnTouchListener {
public LeftImageListener() {
// TODO Auto-generated constructor stub
}
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
leftButtonDown = true;
startTask();
break;
case MotionEvent.ACTION_UP:
leftButtonDown = false;
break;
default:
break;
}
return true;
}
}
}
創建第二個線程是正確的,但你應該用一些動作填充它,因為你創建的線程是空的:)並且你不需要在啟動你的線程后調用run。
Thx Abhishek Birdawade為我做代碼工作:)
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