按下按钮时不断增加整数值 [英] Continuously increase integer value as the button is pressed
问题描述
我是 Android 新手，如果问题很容易回答，我很抱歉.我有两个按钮，一个减少和一个增加按钮，中间是一个显示值的 TextView.
I'm new to Android so sorry if the question is easy to answer. I have two buttons, a decrease and an increase button, and in the middle of them a TextView which displays a value.
当我点击减少按钮时，TextView 中的值在我点击增加按钮时减少和增加，没问题，我可以正常工作，但问题是单击时该值仅增加/减少 1.我想要实现的是，当我连续按下按钮(例如增加按钮)时，该值也在不断增加，并且只有在我松开增加按钮时才会停止.
When I hit the decrease button, the value in the TextView decreases and increases when I hit the increase button, no problem with that, I got that working but the problem is the value only increases/decreases by 1 on a single click. What I'm trying to achieve is that as I continuously press the button (the increase button for example), the value is also continuously increasing and only stops when I release the increase button.
这可能吗?如果是这样，您能否展示一些示例代码或有关如何实现的参考资料?谢谢！
Is that possible? If so, can you show some sample code or references on how to implement that? Thanks!
这是我的 main.xml
Here is my main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="44dp"
android:gravity="center_horizontal" >
<Button android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="<" />
<TextView android:id="@+id/textView1"
android:layout_width="50dp"
android:layout_height="fill_parent"
android:layout_alignBottom="@+id/button1"
android:layout_toRightOf="@+id/button1"
android:gravity="center"
android:text="45" />
<Button android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toRightOf="@+id/textView1"
android:text=">" />
</RelativeLayout>
</RelativeLayout>
这是我的 Main.java
and here is my Main.java
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class Main extends Activity {
private Button _decrease;
private Button _increase;
private TextView _value;
private static int _counter = 45;
private String _stringVal;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
_decrease = (Button) findViewById(R.id.button1);
_increase = (Button) findViewById(R.id.button2);
_value = (TextView) findViewById(R.id.textView1);
_decrease.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.d("src", "Decreasing value...");
_counter--;
_stringVal = Integer.toString(_counter);
_value.setText(_stringVal);
}
});
_increase.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.d("src", "Increasing value...");
_counter++;
_stringVal = Integer.toString(_counter);
_value.setText(_stringVal);
}
});
}
}
推荐答案
为此，您需要一个线程来在您长按按钮时更新整数值.
For that to work, you need a thread that will update the integer value when you long press on a button.
在您的活动中创建处理程序:
Create a handler in your activity:
private Handler repeatUpdateHandler = new Handler();
还有 2 个变量，它们将说明:是递增还是递减?一次只有一组.
And 2 vars which will state: is it increment or decrement? Only one set at a time.
private boolean mAutoIncrement = false;
private boolean mAutoDecrement = false;
和现在的数值
public int mValue;
还有一个将在另一个线程中运行的类:
And a class that will run in another thread:
class RptUpdater implements Runnable {
public void run() {
if( mAutoIncrement ){
increment();
repeatUpdateHandler.postDelayed( new RptUpdater(), REP_DELAY );
} else if( mAutoDecrement ){
decrement();
repeatUpdateHandler.postDelayed( new RptUpdater(), REP_DELAY );
}
}
}
为您的按钮添加一个长按监听器:
Add a long press listener to your button:
mBTIncrement.setOnLongClickListener(
new View.OnLongClickListener(){
public boolean onLongClick(View arg0) {
mAutoIncrement = true;
repeatUpdateHandler.post( new RptUpdater() );
return false;
}
}
);
mBTIncrement.setOnTouchListener( new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
if( (event.getAction()==MotionEvent.ACTION_UP || event.getAction()==MotionEvent.ACTION_CANCEL)
&& mAutoIncrement ){
mAutoIncrement = false;
}
return false;
}
});
在上面的例子中，按钮是递增的.创建另一个按钮，将 mAutoDecrement 设置为 true.
In the above case the button is the increment one. Create another button which will set mAutoDecrement to true.
并且 decrement() 将是一个函数，它将像这样设置您的实例 int 变量:
And decrement() will be a function, which will set your instance int variable like this:
public void decrement(){
mValue--;
_value.setText( ""+mValue );
}
你计算出增量.哦，REP_DELAY 是一个静态 int 变量，设置为 50.
You figure the increment out. Oh and REP_DELAY is a static int variable set to 50.
我看到这是 Jeffrey Cole 的开源 NumberPicker 的摘录，可在 http://www.technologichron.net/ 必须添加正确的作者署名.
I see this is an excerpt from Jeffrey Cole's open source NumberPicker available at http://www.technologichron.net/ Proper author's attribution must be added.
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