我正在尝试自定义我的字体，到目前为止已找到使用onBufferDraw（）方法的解决方案。我从这个链接检索方法： https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/inputmethodservice/KeyboardView.java
尝试使用我自己的自定义字体的函数，并在我的xml中添加了类作为键盘视图。
public class MyKeyboardView extends KeyboardView {
private boolean caps = false;
private Keyboard keyboard;
private static final boolean DEBUG = false;
private static final int NOT_A_KEY = -1;
private static final int[] KEY_DELETE = { Keyboard.KEYCODE_DELETE };
private static final int[] LONG_PRESSABLE_STATE_SET = { R.attr.state_long_pressable };
private Keyboard mKeyboard;
private int mCurrentKeyIndex = NOT_A_KEY;
private int mLabelTextSize;
private int mKeyTextSize;
private int mKeyTextColor;
private float mShadowRadius;
private int mShadowColor;
private float mBackgroundDimAmount;
private TextView mPreviewText;
private PopupWindow mPreviewPopup;
private int mPreviewTextSizeLarge;
private int mPreviewOffset;
private int mPreviewHeight;
// Working variable
private final int[] mCoordinates = new int[2];
private PopupWindow mPopupKeyboard;
private View mMiniKeyboardContainer;
private KeyboardView mMiniKeyboard;
private boolean mMiniKeyboardOnScreen;
private View mPopupParent;
private int mMiniKeyboardOffsetX;
private int mMiniKeyboardOffsetY;
private Map<Key,View> mMiniKeyboardCache;
private Key[] mKeys;
/** Listener for {@link OnKeyboardActionListener}. */
private OnKeyboardActionListener mKeyboardActionListener;
private static final int MSG_SHOW_PREVIEW = 1;
private static final int MSG_REMOVE_PREVIEW = 2;
private static final int MSG_REPEAT = 3;
private static final int MSG_LONGPRESS = 4;
private static final int DELAY_BEFORE_PREVIEW = 0;
private static final int DELAY_AFTER_PREVIEW = 70;
private static final int DEBOUNCE_TIME = 70;
private int mVerticalCorrection;
private int mProximityThreshold;
private boolean mPreviewCentered = false;
private boolean mShowPreview = true;
private boolean mShowTouchPoints = true;
private int mPopupPreviewX;
private int mPopupPreviewY;
private int mLastX;
private int mLastY;
private int mStartX;
private int mStartY;
private boolean mProximityCorrectOn;
private Paint mPaint;
private Rect mPadding;
private long mDownTime;
private long mLastMoveTime;
private int mLastKey;
private int mLastCodeX;
private int mLastCodeY;
private int mCurrentKey = NOT_A_KEY;
private int mDownKey = NOT_A_KEY;
private long mLastKeyTime;
private long mCurrentKeyTime;
private int[] mKeyIndices = new int[12];
private GestureDetector mGestureDetector;
private int mPopupX;
private int mPopupY;
private int mRepeatKeyIndex = NOT_A_KEY;
private int mPopupLayout;
private boolean mAbortKey;
private Key mInvalidatedKey;
private Rect mClipRegion = new Rect(0, 0, 0, 0);
private boolean mPossiblePoly;
private int mSwipeThreshold;
private boolean mDisambiguateSwipe;
// Variables for dealing with multiple pointers
private int mOldPointerCount = 1;
private float mOldPointerX;
private float mOldPointerY;
private Drawable mKeyBackground;
private static final int REPEAT_INTERVAL = 50; // ~20 keys per second
private static final int REPEAT_START_DELAY = 400;
private static int MAX_NEARBY_KEYS = 12;
private int[] mDistances = new int[MAX_NEARBY_KEYS];
// For multi-tap
private int mLastSentIndex;
private int mTapCount;
private long mLastTapTime;
private boolean mInMultiTap;
private static final int MULTITAP_INTERVAL = 800; // milliseconds
private StringBuilder mPreviewLabel = new StringBuilder(1);
/** Whether the keyboard bitmap needs to be redrawn before it's blitted. **/
private boolean mDrawPending;
/** The dirty region in the keyboard bitmap */
private Rect mDirtyRect = new Rect();
/** The keyboard bitmap for faster updates */
private Bitmap mBuffer;
/** Notes if the keyboard just changed, so that we could possibly reallocate the mBuffer. */
private boolean mKeyboardChanged;
/** The canvas for the above mutable keyboard bitmap */
private Canvas mCanvas;
public MyKeyboardView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}
public void _setKeyboard(Keyboard kv)
{
this.keyboard=kv;
}
public MyKeyboardView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a =
context.obtainStyledAttributes(
attrs, R.styleable.KeyboardView, defStyle, 0);
LayoutInflater inflate =
(LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int previewLayout = 0;
int keyTextSize = 0;
int n = a.getIndexCount();
for (int i = 0; i < n; i++) {
int attr = a.getIndex(i);
switch (attr) {
case R.styleable.KeyboardView_keyBackground:
mKeyBackground = a.getDrawable(attr);
break;
case R.styleable.KeyboardView_verticalCorrection:
mVerticalCorrection = a.getDimensionPixelOffset(attr, 0);
break;
case R.styleable.KeyboardView_keyPreviewLayout:
previewLayout = a.getResourceId(attr, 0);
break;
case R.styleable.KeyboardView_keyPreviewOffset:
mPreviewOffset = a.getDimensionPixelOffset(attr, 0);
break;
case R.styleable.KeyboardView_keyPreviewHeight:
mPreviewHeight = a.getDimensionPixelSize(attr, 80);
break;
case R.styleable.KeyboardView_keyTextSize:
mKeyTextSize = a.getDimensionPixelSize(attr, 18);
break;
case R.styleable.KeyboardView_keyTextColor:
mKeyTextColor = a.getColor(attr, 0xFF000000);
break;
case R.styleable.KeyboardView_labelTextSize:
mLabelTextSize = a.getDimensionPixelSize(attr, 14);
break;
case R.styleable.KeyboardView_popupLayout:
mPopupLayout = a.getResourceId(attr, 0);
break;
case R.styleable.KeyboardView_shadowColor:
mShadowColor = a.getColor(attr, 0);
break;
case R.styleable.KeyboardView_shadowRadius:
mShadowRadius = a.getFloat(attr, 0f);
break;
}
}
// a = mContext.obtainStyledAttributes(R.styleable.Theme);
mBackgroundDimAmount = a.getFloat(R.styleable.Theme_backgroundDimAmount, 0.5f);
mPreviewPopup = new PopupWindow(context);
if (previewLayout != 0) {
mPreviewText = (TextView) inflate.inflate(previewLayout, null);
mPreviewTextSizeLarge = (int) mPreviewText.getTextSize();
mPreviewPopup.setContentView(mPreviewText);
mPreviewPopup.setBackgroundDrawable(null);
} else {
mShowPreview = false;
}
mPreviewPopup.setTouchable(false);
mPopupKeyboard = new PopupWindow(context);
mPopupKeyboard.setBackgroundDrawable(null);
//mPopupKeyboard.setClippingEnabled(false);
mPopupParent = this;
//mPredicting = true;
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setTextSize(keyTextSize);
mPaint.setTextAlign(Align.CENTER);
mPaint.setAlpha(255);
mPadding = new Rect(0, 0, 0, 0);
mMiniKeyboardCache = new HashMap<Key,View>();
mKeyBackground.getPadding(mPadding);
mSwipeThreshold = (int) (500 * getResources().getDisplayMetrics().density);
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mDrawPending || mBuffer == null || mKeyboardChanged) {
onBufferDraw();
}
canvas.drawBitmap(mBuffer, 0, 0, null);
Paint paint = new Paint();
paint.setTextAlign(Paint.Align.CENTER);
paint.setTextSize(25);
paint.setColor(Color.BLACK);
Typeface custom_font = Typeface.createFromAsset(getContext().getAssets(), "fonts/Roboto-Bold.ttf");
paint.setTypeface(custom_font);
List<Key> keys = getKeyboard().getKeys();
for(Key key: keys) {
if(key.label != null)
{
if(key.label.toString().equals("q") || key.label.toString().equals("Q") )
canvas.drawText(String.valueOf(1), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("w") || key.label.toString().equals("W") )
canvas.drawText(String.valueOf(2), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("e") || key.label.toString().equals("E") )
canvas.drawText(String.valueOf(3), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("r") || key.label.toString().equals("R") )
canvas.drawText(String.valueOf(4), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("t") || key.label.toString().equals("T") )
canvas.drawText(String.valueOf(5), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("y") || key.label.toString().equals("Y") )
canvas.drawText(String.valueOf(6), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("u") || key.label.toString().equals("U") )
canvas.drawText(String.valueOf(7), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("i") || key.label.toString().equals("I") )
canvas.drawText(String.valueOf(8), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("o") || key.label.toString().equals("o") )
canvas.drawText(String.valueOf(9), key.x + (key.width/2)+10, key.y + 25, paint);
else if(key.label.toString().equals("p") || key.label.toString().equals("P") )
canvas.drawText(String.valueOf(0), key.x + (key.width/2)+10, key.y + 25, paint);
else
{
}
}
}
}
private void onBufferDraw() {
if (mBuffer == null || mKeyboardChanged) {
if (mBuffer == null || mKeyboardChanged &&
(mBuffer.getWidth() != getWidth() || mBuffer.getHeight() != getHeight())) {
// Make sure our bitmap is at least 1x1
final int width = Math.max(1, getWidth());
final int height = Math.max(1, getHeight());
mBuffer = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBuffer);
}
invalidateAllKeys();
mKeyboardChanged = false;
}
final Canvas canvas = mCanvas;
canvas.clipRect(mDirtyRect, Op.REPLACE);
if (mKeyboard == null) return;
final Paint paint = mPaint;
final Drawable keyBackground = mKeyBackground;
final Rect clipRegion = mClipRegion;
final Rect padding = mPadding;
final Key[] keys = mKeys;
final Key invalidKey = mInvalidatedKey;
paint.setColor(mKeyTextColor);
boolean drawSingleKey = false;
final int keyCount = keys.length;
for (int i = 0; i < keyCount; i++) {
final Key key = keys[i];
if (drawSingleKey && invalidKey != key) {
continue;
}
int[] drawableState = key.getCurrentDrawableState();
keyBackground.setState(drawableState);
// Switch the character to uppercase if shift is pressed
String label = key.label == null? null : adjustCase(key.label).toString();
final Rect bounds = keyBackground.getBounds();
if (key.width != bounds.right ||
key.height != bounds.bottom) {
keyBackground.setBounds(0, 0, key.width, key.height);
}
keyBackground.draw(canvas);
Typeface custom_font = Typeface.createFromAsset(getContext().getAssets(), "fonts/Roboto-Bold.ttf");
if (label != null) {
// For characters, use large font. For labels like "Done", use small font.
if (label.length() > 1 && key.codes.length < 2) {
paint.setTextSize(mLabelTextSize);
paint.setTypeface(custom_font);
} else {
paint.setTextSize(mKeyTextSize);
paint.setTypeface(custom_font);
}
// Draw a drop shadow for the text
paint.setShadowLayer(mShadowRadius, 0, 0, mShadowColor);
// Draw the text
canvas.drawText(label,
(key.width - padding.left - padding.right) / 2
+ padding.left,
(key.height - padding.top - padding.bottom) / 2
+ (paint.getTextSize() - paint.descent()) / 2 + padding.top,
paint);
// Turn off drop shadow
paint.setShadowLayer(0, 0, 0, 0);
} else if (key.icon != null) {
final int drawableX = (key.width - padding.left - padding.right
- key.icon.getIntrinsicWidth()) / 2 + padding.left;
final int drawableY = (key.height - padding.top - padding.bottom
- key.icon.getIntrinsicHeight()) / 2 + padding.top;
canvas.translate(drawableX, drawableY);
key.icon.setBounds(0, 0,
key.icon.getIntrinsicWidth(), key.icon.getIntrinsicHeight());
key.icon.draw(canvas);
canvas.translate(-drawableX, -drawableY);
}
}
mInvalidatedKey = null;
// Overlay a dark rectangle to dim the keyboard
if (mMiniKeyboardOnScreen) {
paint.setColor((int) (mBackgroundDimAmount * 0xFF) << 24);
canvas.drawRect(0, 0, getWidth(), getHeight(), paint);
}
if (DEBUG && mShowTouchPoints) {
paint.setAlpha(128);
paint.setColor(0xFFFF0000);
canvas.drawCircle(mStartX, mStartY, 3, paint);
canvas.drawLine(mStartX, mStartY, mLastX, mLastY, paint);
paint.setColor(0xFF0000FF);
canvas.drawCircle(mLastX, mLastY, 3, paint);
paint.setColor(0xFF00FF00);
canvas.drawCircle((mStartX + mLastX) / 2, (mStartY + mLastY) / 2, 2, paint);
}
mDrawPending = false;
mDirtyRect.setEmpty();
}
private CharSequence adjustCase(CharSequence label) {
if (mKeyboard.isShifted() && label != null && label.length() < 3
&& Character.isLowerCase(label.charAt(0))) {
label = label.toString().toUpperCase();
}
return label;
}
<com.main.MyKeyboardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/keyboard1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/buttons"
android:keyBackground="@color/background_color"
android:keyTextColor="#000000"
android:keyTextSize="26sp"
android:keyPreviewLayout ="@layout/preview"
android:background="#FFFFFF"
/>
但什么都没发生！我不知道为什么以及我缺少什么来改变字体。