Android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" />

嗯，自己写这个东西，也学到了一些东西，大家有什么更好的方法，大家可以讨论一下。

另外的解决思路：

自定义控件让TextView、Button的drawableLeft和drawableRight与文本一起居中显示

http://blog.csdn.net/catoop/article/details/23947345

TextView的drawableLeft、drawableRight和drawableTop是一个常用、好用的属性，可以在文本的上下左右放置一个图片，而不使用更加复杂布局就能达到，我也常常喜欢用RadioButton的这几个属性实现很多效果，但是苦于不支持让drawbleLeft与文本一起居中，设置gravity为center也无济于事，终于有空研究了一下，这里与大家一起分享。

布局XML

 <com.assistant.expand.customview.DrawableCenterButton
                         android:gravity="left|center_vertical"
                         android:drawableLeft="@drawable/icon_erweima"
                         android:drawablePadding="5dp"
                 android:id="@+id/btn_scale"
                 android:layout_width="fill_parent"
                 android:layout_height="fill_parent"
                 android:background="@android:color/transparent"
                 android:singleLine="true"
                 android:text="扫描二维码签到"
                 android:textColor="@color/color_button2"
                 android:textSize="17sp" />

 /**
  * drawableLeft与文本一起居中显示
  *
  *
  */
 public class DrawableCenterTextView extends TextView {

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

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

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

     @Override
     protected void onDraw(Canvas canvas) {
         Drawable[] drawables = getCompoundDrawables();
         if (drawables != null) {
             Drawable drawableLeft = drawables[0];
             if (drawableLeft != null) {
                 float textWidth = getPaint().measureText(getText().toString());
                 int drawablePadding = getCompoundDrawablePadding();
                 int drawableWidth = 0;
                 drawableWidth = drawableLeft.getIntrinsicWidth();
                 float bodyWidth = textWidth + drawableWidth + drawablePadding;
                 canvas.translate((getWidth() - bodyWidth) / 2, 0);
             }
         }
         super.onDraw(canvas);
     }
 }

下面是用Button的Right 例子

 /**
  * drawableRight与文本一起居中显示
  *
  *
  */
 public class DrawableCenterButton extends Button {

     public DrawableCenterButton(Context context) {
         super(context);
         // TODO Auto-generated constructor stub
     }

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

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


     @Override
     protected void onDraw(Canvas canvas) {
         Drawable[] drawables = getCompoundDrawables();
         if (drawables != null) {
             Drawable drawableLeft = drawables[2];
                 if (drawableLeft != null) {

                 float textWidth = getPaint().measureText(getText().toString());
                 int drawablePadding = getCompoundDrawablePadding();
                 int drawableWidth = 0;
                 drawableWidth = drawableLeft.getIntrinsicWidth();
                 float bodyWidth = textWidth + drawableWidth + drawablePadding;
                 setPadding(0, 0, (int)(getWidth() - bodyWidth), 0);
                 canvas.translate((getWidth() - bodyWidth) / 2, 0);
             }
         }
         super.onDraw(canvas);
     }
 }