Android编程中TextView宽度过大导致Drawable无法居中问题解决方法

本文实例讲述了Android编程中TextView宽度过大导致Drawable无法居中问题解决方法。分享给大家供大家参考，具体如下：

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(); 
 } 
  
 private void initVariable() { 
  textWidth = (int) (getPaint().measureText(text)); 
  final Rect rect = new Rect(); 
  getPaint().getTextBounds(text, 0, 1, rect); 
  textHeight = rect.height(); 
 } 
  
 public void setText(String text) { 
  this.text = text; 
  initVariable(); 
  invalidate(); 
 } 
  
 public String getText() { 
  return text; 
 } 
  
 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(); 
 } 
  
 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()); 
    
   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。

希望本文所述对大家Android程序设计有所帮助。

您可能感兴趣的文章:Android开发使用Drawable绘制圆角与圆形图案功能示例Android自定义Drawable实现圆形和圆角Android自定义Drawable实现圆角效果Android Bitmap和Drawable相互转换的简单代码android 放大镜ShapeDrawable妙用分享android中图形图像处理之drawable用法分析基于android中的各种颜色在drawable.xml中的值详解Android App开发中将View或Drawable转为Bitmap的方法Android LayerDrawable使用实例Android 让自定义TextView的drawableLeft与文本一起居中关于Android中drawable必知的一些规则Android开发基于Drawable实现圆角矩形的方法