我想知道我的应用程序在选择时是否可以放大文本框。由于该应用程序适用于通常较老的人，我希望这是一个可能的选择。另外，大家都知道，这与WebView的任何内容都没有关系。该应用程序只是一组文本框。
答案 0 :(得分：2)
当选择时放大？ There is a class on github by @ JadeByfield89 扩展EditText并使其捏Zoomable 。
CODE ZoomableEditText ：
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;
/**
* Created by Jade Byfield on 3/29/2014.
*/
// ImageView that draws a grid on top of it's canvas
public class ZoomEditTextView extends EditText {
// touch tools
private static final int INVALID_POINTER_ID = -1;
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
// The Ôactive pointerÕ is the one currently moving our object.
private int mActivePointerId = INVALID_POINTER_ID;
private float mPosX;
private float mPosY;
private float mLastTouchX;
private float mLastTouchY;
private Bitmap mBitmap = null;
private Paint mPaint;
private Path mPath;
private Paint mBitmapPaint;
private Paint mCirclePaint;
private Path mCirclePath;
private Paint mDrawingPaint;
private List<Path> mPaths = new ArrayList<Path>();
private List<Paint> mPaints = new ArrayList<Paint>();
private float mBrushSize = 12.0f;
private Drawable mDrawable;
private Paint mRectPaint;
private Context mContext;
public ZoomEditTextView(Context context, AttributeSet attrs) {
super(context, attrs, 0);
this.mContext = context;
init();
}
public ZoomEditTextView(Context context) {
super(context, null, 0);
this.mContext = context;
init();
// this.setOnTouchListener(new OnTouchListener() {
//
// @Override
// public boolean onTouch(View v, MotionEvent me) {
//
// InputMethodManager imm = (InputMethodManager) mContext
// .getSystemService(mContext.INPUT_METHOD_SERVICE);
// imm.showSoftInput(v, InputMethodManager.SHOW_IMPLICIT);
//
// return true;
// }
//
// });
}
private void init() {
// Create our ScaleGestureDetector
mScaleDetector = new ScaleGestureDetector(mContext, new ScaleListener());
// Sets up drawing tools
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mCirclePaint = new Paint();
mCirclePath = new Path();
mCirclePaint.setAntiAlias(true);
mCirclePaint.setColor(Color.CYAN);
mCirclePaint.setStyle(Paint.Style.STROKE);
mCirclePaint.setStrokeJoin(Paint.Join.MITER);
mCirclePaint.setStrokeWidth(4f);
//
mDrawingPaint = new Paint();
mDrawingPaint.setAntiAlias(true);
mDrawingPaint.setDither(true);
mDrawingPaint.setColor(Color.GREEN);
mDrawingPaint.setStyle(Paint.Style.STROKE);
mDrawingPaint.setStrokeJoin(Paint.Join.ROUND);
mDrawingPaint.setStrokeCap(Paint.Cap.ROUND);
mDrawingPaint.setStrokeWidth(mBrushSize);
mRectPaint = new Paint(Paint.ANTI_ALIAS_FLAG) ;
mRectPaint.setStyle(Paint.Style.STROKE);
mRectPaint.setColor(Color.WHITE);
mDrawable = mContext.getResources().getDrawable(R.drawable.ic_launcher);
mDrawable.setBounds(0, 0, mDrawable.getIntrinsicWidth(),
mDrawable.getIntrinsicHeight());
// setDrawingCacheEnabled(true);
// buildDrawingCache();
}
@Override
protected void onDraw(Canvas canvas) {
canvas.save();
//
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor);
// canvas.drawRect(new Rect(0, 0, canvas.getWidth(),
// canvas.getHeight()), mRectPaint);
super.onDraw(canvas);
// mDrawable.draw(canvas);
// if (mBitmap != null && canvas != null) {
// canvas.drawBitmap(mBitmap, mPosX, mPosY, mPaint);
// }
canvas.restore();
}
// Listen for multi-touch drag event and redraw the view accordingly
@Override
public boolean onTouchEvent(MotionEvent event) {
// Let the ScaleGestureDetector inspect all events.
mScaleDetector.onTouchEvent(event);
final int action = event.getAction();
switch (action) {
// a touch down
case MotionEvent.ACTION_DOWN: {
// Scale detector is not in progress
if (!mScaleDetector.isInProgress()) {
final float x = event.getX();
final float y = event.getY();
// Save the ID of this pointer
mActivePointerId = event.getPointerId(0);
// Remember where we started
mLastTouchX = x;
mLastTouchY = y;
// Save the ID of this pointer
mActivePointerId = event.getPointerId(0);
break;
}
}
case MotionEvent.ACTION_MOVE: {
// Only move the image if the scale detector is not in progress
if (!mScaleDetector.isInProgress()) {
// Find the index of active pointer and save its position
final int pointerIndex = event.findPointerIndex(mActivePointerId);
final float x = event.getX(pointerIndex);
final float y = event.getY(pointerIndex);
// mBitmap = getDrawingCache();
// Calculate the distance moved
float dx = x - mLastTouchX;
float dy = y - mLastTouchY;
// Move the object
mPosX += dx;
mPosY += dy;
// Remember this touch position for the next move event
mLastTouchX = x;
mLastTouchY = y;
// Invalidate to request a redraw
invalidate();
// break;
} /*
* else {
*
* final float gx = mScaleDetector.getFocusX(); final float gy =
* mScaleDetector.getFocusY();
*
* final float gdx = gx - mLastGestureX; final float gdy = gy -
* mLastGestureY;
*
* mPosX += gdx; mPosY += gdy;
*
* invalidate();
*
* mLastGestureX = gx; mLastGestureY = gy;
*
* }
*/
break;
}
case MotionEvent.ACTION_UP: {
InputMethodManager imm = (InputMethodManager) mContext.getSystemService(mContext.INPUT_METHOD_SERVICE);
imm.showSoftInput(this, InputMethodManager.SHOW_IMPLICIT);
// Reset the active pointer id
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
// Extract the index of the pointer that left the touch sensor
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = event.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
if (event.getPointerCount() >= 2) {
mLastTouchX = event.getX(newPointerIndex);
mLastTouchY = event.getY(newPointerIndex);
}
mActivePointerId = event.getPointerId(newPointerIndex);
} else {
final int tempPointerIndex = event
.findPointerIndex(mActivePointerId);
mLastTouchX = event.getX(tempPointerIndex);
mLastTouchY = event.getY(tempPointerIndex);
}
break;
}
}
return true;
}
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));
invalidate();
return true;
}
}
}