我承认我是个新手,在尝试开发Android应用。我一直在网上寻找如何实现“按住按钮重复操作”的建议——我创建了一个由按钮组成的自定义数字键盘,并希望拥有类似于退格键的行为。已经做到这一步了,我叫来了一个朋友,他以前没有编写过Android应用,但是了解很多C# / Java知识,似乎知道自己在做什么。
下面的代码运行良好,但我觉得它可以更简洁地实现。如果我漏掉了什么,我道歉,但希望这能解释我的思路。我认为onTouchListener没问题,但线程处理的方式感觉不太对。
有更好或更简单的方法吗?
public class MyApp extends Activity {
private boolean deleteThreadRunning = false;
private boolean cancelDeleteThread = false;
private Handler handler = new Handler();
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
//May have missed some declarations here...
Button_Del.setOnTouchListener(new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
{
handleDeleteDown();
return true;
}
case MotionEvent.ACTION_UP:
{
handleDeleteUp();
return true;
}
default:
return false;
}
}
private void handleDeleteDown() {
if (!deleteThreadRunning)
startDeleteThread();
}
private void startDeleteThread() {
Thread r = new Thread() {
@Override
public void run() {
try {
deleteThreadRunning = true;
while (!cancelDeleteThread) {
handler.post(new Runnable() {
@Override
public void run() {
deleteOneChar();
}
});
try {
Thread.sleep(100);
} catch (InterruptedException e) {
throw new RuntimeException(
"Could not wait between char delete.", e);
}
}
}
finally
{
deleteThreadRunning = false;
cancelDeleteThread = false;
}
}
};
// actually start the delete char thread
r.start();
}
});
}
private void handleDeleteUp() {
cancelDeleteThread = true;
}
private void deleteOneChar()
{
String result = getNumberInput().getText().toString();
int Length = result.length();
if (Length > 0)
getNumberInput().setText(result.substring(0, Length-1));
//I've not pasted getNumberInput(), but it gets the string I wish to delete chars from
}