改良版sidebar 通訊錄導航欄A-Z

我在網上搜了個sidebar的源碼， 但是在xml裏面開啓大屏模式後，導航欄字體變得很小

<supports-screens
        android:anyDensity="true"
        android:largeScreens="true"
        android:normalScreens="true"
        android:smallScreens="true"
        android:xlargeScreens="true" />

本來正常的應該是：

但是在我的note4上面卻顯示這樣

很小的字體，看了下源碼 ， 原來是原作者把字體寫死了。

// 獲取焦點改變背景顏色.
		int height = getHeight();// 獲取對應高度
		int width = getWidth(); // 獲取對應寬度
		int singleHeight = height / b.length;// 獲取每一個字母的高度

		for (int i = 0; i < b.length; i++) {
			paint.setColor(Color.rgb(33, 65, 98));
			// paint.setColor(Color.WHITE);
			paint.setTypeface(Typeface.DEFAULT_BOLD);
			paint.setAntiAlias(true);
			paint.setTextSize(20);
			
			// 選中的狀態
			if (i == choose) {
				paint.setColor(Color.parseColor("#3399ff"));
				paint.setFakeBoldText(true);
			}
			// x座標等於中間-字符串寬度的一半.
			float xPos = width / 2 - paint.measureText(b[i]) / 2;
			float yPos = singleHeight * i + singleHeight;
			canvas.drawText(b[i], xPos, yPos, paint);
			paint.reset();// 重置畫筆

然後我改了下，把字體設置成相對大小的。

/**
	 * 重寫這個方法
	 */
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);

		if (itemHeight == -1) {
			itemHeight = getHeight() / b.length;
		}

		// 獲取焦點改變背景顏色.
		int height = getHeight();// 獲取對應高度
		int width = getWidth(); // 獲取對應寬度
		int singleHeight = height / b.length;// 獲取每一個字母的高度

		for (int i = 0; i < b.length; i++) {
			paint.setColor(Color.rgb(33, 65, 98));
			// paint.setColor(Color.WHITE);
			paint.setTypeface(Typeface.DEFAULT_BOLD);
			paint.setAntiAlias(true);
			//paint.setTextSize(20);
			paint.setTextSize(itemHeight - 10);
			// 選中的狀態
			if (i == choose) {
				paint.setColor(Color.parseColor("#3399ff"));
				paint.setFakeBoldText(true);
			}
			// x座標等於中間-字符串寬度的一半.
			float xPos = width / 2 - paint.measureText(b[i]) / 2;
			float yPos = singleHeight * i + singleHeight;
			canvas.drawText(b[i], xPos, yPos, paint);
			paint.reset();// 重置畫筆
		}

	}

完整的源碼是：

package net.mwplay.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.graphics.drawable.ColorDrawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;

public class SideBar extends View {
	// 觸摸事件
	private OnTouchingLetterChangedListener onTouchingLetterChangedListener;
	// 26個字母
	public static String[] b = { "A", "B", "C", "D", "E", "F", "G", "H", "I",
			"J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
			"W", "X", "Y", "Z", "#" };
	private int choose = -1;// 選中
	private Paint paint = new Paint();

	private TextView mTextDialog;

	private float itemHeight = -1;

	/**
	 * 爲SideBar設置顯示字母的TextView
	 * 
	 * @param mTextDialog
	 */
	public void setTextView(TextView mTextDialog) {
		this.mTextDialog = mTextDialog;
	}

	public SideBar(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
	}

	public SideBar(Context context, AttributeSet attrs) {
		super(context, attrs);
	}

	public SideBar(Context context) {
		super(context);
	}

	/**
	 * 重寫這個方法
	 */
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);

		if (itemHeight == -1) {
			itemHeight = getHeight() / b.length;
		}

		// 獲取焦點改變背景顏色.
		int height = getHeight();// 獲取對應高度
		int width = getWidth(); // 獲取對應寬度
		int singleHeight = height / b.length;// 獲取每一個字母的高度

		for (int i = 0; i < b.length; i++) {
			paint.setColor(Color.rgb(33, 65, 98));
			// paint.setColor(Color.WHITE);
			paint.setTypeface(Typeface.DEFAULT_BOLD);
			paint.setAntiAlias(true);
			//paint.setTextSize(20);
			paint.setTextSize(itemHeight - 10);
			// 選中的狀態
			if (i == choose) {
				paint.setColor(Color.parseColor("#3399ff"));
				paint.setFakeBoldText(true);
			}
			// x座標等於中間-字符串寬度的一半.
			float xPos = width / 2 - paint.measureText(b[i]) / 2;
			float yPos = singleHeight * i + singleHeight;
			canvas.drawText(b[i], xPos, yPos, paint);
			paint.reset();// 重置畫筆
		}

	}

	@Override
	public boolean dispatchTouchEvent(MotionEvent event) {
		final int action = event.getAction();
		final float y = event.getY();// 點擊y座標
		final int oldChoose = choose;
		final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;
		final int c = (int) (y / getHeight() * b.length);// 點擊y座標所佔總高度的比例*b數組的長度就等於點擊b中的個數.

		switch (action) {
		case MotionEvent.ACTION_UP:
			setBackgroundDrawable(new ColorDrawable(0x00000000));
			choose = -1;//
			invalidate();
			if (mTextDialog != null) {
				mTextDialog.setVisibility(View.INVISIBLE);
			}
			break;

		default:
			// setBackgroundResource(R.drawable.sidebar_background);
			if (oldChoose != c) {
				if (c >= 0 && c < b.length) {
					if (listener != null) {
						listener.onTouchingLetterChanged(b[c]);
					}
					if (mTextDialog != null) {
						mTextDialog.setText(b[c]);
						mTextDialog.setVisibility(View.VISIBLE);
					}

					choose = c;
					invalidate();
				}
			}

			break;
		}
		return true;
	}

	/**
	 * 向外公開的方法
	 * 
	 * @param onTouchingLetterChangedListener
	 */
	public void setOnTouchingLetterChangedListener(
			OnTouchingLetterChangedListener onTouchingLetterChangedListener) {
		this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;
	}

	/**
	 * 接口
	 * 
	 * @author coder
	 * 
	 */
	public interface OnTouchingLetterChangedListener {
		public void onTouchingLetterChanged(String s);
	}

}

沒有其他意思，只是想記錄下自己犯過的錯。希望對大家有幫助。