如何放大文本框

Question

我想知道是否可以让我的应用程序在选中时放大文本框。由于该应用程序适用于一般年龄较大的人，因此我希望这是一个可能的选择。另外为了让大家知道，这与WebView的任何事情都没有关系。该应用程序只是一组文本框。

Answer 1

放大时选择？There is a class on github by@ JadeByfield89它扩展了EditText，并使其成为捏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; 
     } 
    } 

}