如何创建水平数字选择器并调整其大小

Question

我尝试在android中创建一个水平数字选择器。这似乎是不可能的。另外，我想知道如何调整numberpicker的大小。还有一件事，模拟器中的按钮（+和 - ）似乎不够明显。为什么？我怎样才能克服所有这些挑战？

Answer 1

来源codejeff

动态调整NumberPicker的大小 @Override NumberPicker构造函数并设置以下常量

  

ELEMENT_HEIGHT =＆GT;高度+/-按钮
  ELEMENT_WIDTH =＆gt;宽度+/-按钮
  MINIMUM =＆gt;最小值NumberPicker
  MAXIMUM =＆gt;最大值NumberPicker
  TEXT_SIZE =＆GT; NumberPicker

中的数字文字大小

如果你不想搞砸代码。

  

只需根据 NumberPicker.java 中的要求更改这些值   private final long REPEAT_DELAY = 50;
  private final int ELEMENT_HEIGHT = 60;
  private final int ELEMENT_WIDTH = ELEMENT_HEIGHT;
  private final int MINIMUM = 0;
  private final int MAXIMUM = 999;

private final int TEXT_SIZE = 30;` 的 NumberPickerExample.java

public class NumberPickerExample extends Activity {

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
}
}

<强> NumberPicker.java

public class NumberPicker extends LinearLayout {

private final long REPEAT_DELAY = 50;

private final int ELEMENT_HEIGHT = 60;
private final int ELEMENT_WIDTH = ELEMENT_HEIGHT; // you're all squares, yo

private final int MINIMUM = 0;
private final int MAXIMUM = 999;

private final int TEXT_SIZE = 30;

public Integer value;

Button decrement;
Button increment;
public EditText valueText;

private Handler repeatUpdateHandler = new Handler();

private boolean autoIncrement = false;
private boolean autoDecrement = false;

class RepetetiveUpdater implements Runnable {
    public void run() {
        if( autoIncrement ){
            increment();
            repeatUpdateHandler.postDelayed( new RepetetiveUpdater(), REPEAT_DELAY );
        } else if( autoDecrement ){
            decrement();
            repeatUpdateHandler.postDelayed( new RepetetiveUpdater(), REPEAT_DELAY );
        }
    }
}
public NumberPicker( Context context, AttributeSet attributeSet ) {
    super(context, attributeSet);

    this.setLayoutParams( new LinearLayout.LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT ) );
    LayoutParams elementParams = new LinearLayout.LayoutParams( ELEMENT_HEIGHT, ELEMENT_WIDTH );
    initDecrementButton( context );
    initValueEditText( context );
    initIncrementButton( context );
    if( getOrientation() == VERTICAL ){
        addView( increment, elementParams );
        addView( valueText, elementParams );
        addView( decrement, elementParams );
    } else {
        addView( decrement, elementParams );
        addView( valueText, elementParams );
        addView( increment, elementParams );
    }
}

private void initIncrementButton( Context context){
    increment = new Button( context );
    increment.setTextSize( TEXT_SIZE );
    increment.setText( "+" );

    // Increment once for a click
    increment.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            increment();
        }
    });

    increment.setOnLongClickListener( 
            new View.OnLongClickListener(){
                public boolean onLongClick(View arg0) {
                    autoIncrement = true;
                    repeatUpdateHandler.post( new RepetetiveUpdater() );
                    return false;
                }
            }
    );

    increment.setOnTouchListener( new View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            if( event.getAction() == MotionEvent.ACTION_UP && autoIncrement ){
                autoIncrement = false;
            }
            return false;
        }
    });
}

private void initValueEditText( Context context){

    value = new Integer( 0 );

    valueText = new EditText( context );
    valueText.setTextSize( TEXT_SIZE );

    valueText.setOnKeyListener(new View.OnKeyListener() {
        public boolean onKey(View v, int arg1, KeyEvent event) {
            int backupValue = value;
            try {
                value = Integer.parseInt( ((EditText)v).getText().toString() );
            } catch( NumberFormatException nfe ){
                value = backupValue;
            }
            return false;
        }
    });

    valueText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
        public void onFocusChange(View v, boolean hasFocus) {
            if( hasFocus ){
                ((EditText)v).selectAll();
            }
        }
    });
    valueText.setGravity( Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL );
    valueText.setText( value.toString() );
    valueText.setInputType( InputType.TYPE_CLASS_NUMBER );
}

private void initDecrementButton( Context context){
    decrement = new Button( context );
    decrement.setTextSize( TEXT_SIZE );
    decrement.setText( "-" );


    decrement.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            decrement();
        }
    });


    decrement.setOnLongClickListener( 
            new View.OnLongClickListener(){
                public boolean onLongClick(View arg0) {
                    autoDecrement = true;
                    repeatUpdateHandler.post( new RepetetiveUpdater() );
                    return false;
                }
            }
    );

    decrement.setOnTouchListener( new View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            if( event.getAction() == MotionEvent.ACTION_UP && autoDecrement ){
                autoDecrement = false;
            }
            return false;
        }
    });
}

public void increment(){
    if( value < MAXIMUM ){
        value = value + 1;
        valueText.setText( value.toString() );
    }
}

public void decrement(){
    if( value > MINIMUM ){
        value = value - 1;
        valueText.setText( value.toString() );
    }
}

public int getValue(){
    return value;
}

public void setValue( int value ){
    if( value > MAXIMUM ) value = MAXIMUM;
    if( value >= 0 ){
        this.value = value;
        valueText.setText( this.value.toString() );
    }
}

}

<强> main.xml中

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/MainLayout"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_vertical|center_horizontal">


    <net.learning.android.control.NumberPicker
        android:id="@+id/Picker1"
        android:orientation="horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
    </net.learning.android.control.NumberPicker>


</LinearLayout>

<强>输出