关于TextView 宽度过大导致Drawable无法居中问题
在做项目的时候，很多时候我们都要用到文字和图片一起显示，一般设置TextView的DrawableLeft、DrawableRight、DrawableTop、DrawableBottom就行了。但是有一种情况是当TextView的熟悉是fill_parent或者使用权重的时候并且设置了起Gravity的ceter的时候，Drawable图片是无法一起居中的，为了解决其，我们一般再套一层布局，然后设置TextView的熟悉是wrap_content，但是有时候嵌套过多的布局的时候，有可能发生StackOverFlow，所以必须要优化，下面说一下其中的一个解决方案。先上图
这个解决方案很粗糙，局限性很大，文字不能换行，换行之后就不准了，下面是源码：
package com.example.testandroid;
import java.lang.ref.WeakReference;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.TextView;
public class DrawableTextView extends TextView {
private WeakReference<Bitmap> normalReference;
private WeakReference<Bitmap> pressReference;
private WeakReference<Bitmap> showReference;
private int normalColor = Color.WHITE, pressColor = Color.WHITE;
private String text;
private int textWidth = 0;
private int textHeight = 0;
public DrawableTextView(Context context) {
super(context);
}
public DrawableTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public DrawableTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
initText();
}
private void initText() {
text = super.getText().toString();
initVariable();
}
/**
* 初始化，测量Textview内容的长度，高度
*/
private void initVariable() {
textWidth = (int) (getPaint().measureText(text));
final Rect rect = new Rect();
getPaint().getTextBounds(text, 0, 1, rect);
textHeight = rect.height();
}
/**
* 设置TextView的内容
* @param text
*/
public void setText(String text) {
this.text = text;
initVariable();
invalidate();
}
/**
* 获取TextView内容
*/
public String getText() {
return text;
}
/**
* 设置TextView的Drawable内容，目前仅支持DrawableLeft
* @param normalDrawableId
* DrawableLeft的normal状态Id
* @param pressDrawableId
* DrawableLeft的press状态的Id（没有press状态，请传-1）
*/
public void setDrawableLeftId(final int normalDrawableId, final int pressDrawableId) {
normalReference = new WeakReference<Bitmap>(BitmapFactory.decodeResource(getResources(), normalDrawableId));
if (pressDrawableId != -1) {
pressReference = new WeakReference<Bitmap>(BitmapFactory.decodeResource(getResources(), pressDrawableId));
}
showReference = normalReference;
invalidate();
}
/**
* 设置TextView的Color
* @param normalColor
* TextView normal状态的Color值
* @param pressDrawableId
* TextView press状态的Color值（如果没有press状态，请传与normal状态的值）
*/
public void setTextColor(final int normalColor, final int pressColor) {
this.normalColor = normalColor;
this.pressColor = pressColor;
getPaint().setColor(normalColor);
initVariable();
}
@Override
protected void onDraw(Canvas canvas) {
if (showReference != null && showReference.get() != null) {
final int bitmapWidth = showReference.get().getWidth();
final int bitmapHeight = showReference.get().getHeight();
final int viewHeight = getHeight();
final int drawablePadding = getCompoundDrawablePadding();
final int start = (getWidth() - (bitmapWidth + drawablePadding + textWidth)) >> 1;
canvas.drawBitmap(showReference.get(), start, (viewHeight >> 1) - (bitmapHeight >> 1), getPaint());
/**
* 注意改方法，第三个参数y，本人也被误导了好久，原来在画文字的时候，y表示文字最后的位置（不是下笔点的起始位置）
* 所以为什么 是TextView高度的一半（中间位置） + 文字高度的一半 = 文字居中
*/
canvas.drawText(text, start + drawablePadding + bitmapWidth, (viewHeight >> 1) + (textHeight >> 1), getPaint());
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
if (pressReference != null && pressReference.get() != null) {
showReference = pressReference;
}
getPaint().setColor(pressColor);
} else if (event.getAction() == MotionEvent.ACTION_UP) {
if (normalReference != null && normalReference.get() != null) {
showReference = normalReference;
}
getPaint().setColor(normalColor);
}
invalidate();
return super.onTouchEvent(event);
}
}xml布局：
<com.example.testandroid.DrawableTextView
android:id="@+id/my_textview"
android:layout_width="fill_parent"
android:layout_marginTop="20dp"
android:background="@drawable/text_selector"
android:drawablePadding="8dp"
android:textColor="@color/standard_orange"
android:layout_height="wrap_content"
android:padding="15dp"
android:textSize="16sp"
android:text="有Drawable的TextView" />调用代码：
DrawableTextView drawableTextView = (DrawableTextView) getView().findViewById(R.id.my_textview);
drawableTextView.setDrawableLeftId(R.drawable.bg_btn_delete_normal, R.drawable.bg_btn_delete_pressed);
drawableTextView.setTextColor(getResources().getColor(R.color.standard_orange), getResources().getColor(R.color.standard_white));
drawableTextView.setText("我在动态修改Text啦");
其实还有更加方便的方法，下面朋友借鉴某个网友的代码（地址我就不知道了）：
@Override
protected void onDraw(Canvas canvas) {
Drawable[] drawables = getCompoundDrawables();
if (drawables != null) {
Drawable drawableLeft = drawables[0];
if (drawableLeft != null) {
final float textWidth = getPaint().measureText(getText().toString());
final int drawablePadding = getCompoundDrawablePadding();
final int drawableWidth = drawableLeft.getIntrinsicWidth();
final float bodyWidth = textWidth + drawableWidth + drawablePadding;
canvas.translate((getWidth() - bodyWidth) / 2, 0);
}
}
super.onDraw(canvas);
}
xml布局：
<com.example.testandroid.DrawableTextView
android:id="@+id/my_textview"
android:layout_width="fill_parent"
android:layout_marginTop="20dp"
android:background="@drawable/text_selector"
android:drawablePadding="8dp"
android:drawableLeft="@drawable/clear_edittext_selector"
android:textColor="@color/text_color_selector"
android:layout_height="wrap_content"
android:padding="15dp"
android:textSize="16sp"
android:text="有Drawable的TextView" />