Android TextView内容过长加省略号，点击显示全部内容

在Android TextView中有个内容过长加省略号的属性，即ellipsize，用法如下：

在xml中：
android:ellipsize="end"　　  省略号在结尾
android:ellipsize="start" 　　省略号在开头
android:ellipsize="middle"省略号在中间
android:ellipsize="marquee" 跑马灯
最好加一个TextView显示行数的约束，例如：

android:singleline="true"或者android:lines="2"

在java文件中：
tv.setEllipsize(TextUtils.TruncateAt.valueOf("END"));
tv.setEllipsize(TextUtils.TruncateAt.valueOf("START"));
tv.setEllipsize(TextUtils.TruncateAt.valueOf("MIDDLE"));
tv.setEllipsize(TextUtils.TruncateAt.valueOf("MARQUEE"));
最好加一个TextView显示行数的约束，例如：
tv.setSingleLine(true);

不仅对于textview有此属性，对于editext也有，不过它不支持marquee。

文字展开和收缩

public class DemoActivity extends BaseActivity {
<wbr><wbr>@Override
<wbr>protected void onCreate(Bundle savedInstanceState) {
<wbr><wbr>super.onCreate(savedInstanceState);
<wbr><wbr>setContentView(R.layout.main);</wbr></wbr></wbr></wbr></wbr></wbr></wbr>
    // 在xml文件中设置了android:singleline="true"
<wbr><wbr>final TextView tv = (TextView)findViewById(R.id.task_2_title);
<wbr><wbr>//tv.setMovementMethod(ScrollingMovementMethod.getInstance());
<wbr><wbr>tv.setOnClickListener(new OnClickListener() {
<wbr><wbr><wbr>Boolean flag = true;
<wbr><wbr><wbr>@Override
<wbr><wbr><wbr>public void onClick(View v) {
<wbr><wbr><wbr><wbr>Log.i("tv.getLineCount()",tv.getHeight()+"");
<wbr><wbr><wbr><wbr>if(flag){
<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>flag = false;
<wbr><wbr><wbr><wbr><span style="word-wrap:normal; word-break:normal"><wbr>tv.setEllipsize(null); // 展开
</wbr></span><wbr><wbr><wbr><wbr><wbr>//tv.setSingleLine(flag);
<wbr><wbr><wbr><wbr>}else{
<wbr><wbr><wbr><wbr><wbr>flag = true;
<wbr><wbr><wbr><wbr><span style="word-wrap:normal; word-break:normal"><wbr>tv.setEllipsize(TextUtils.TruncateAt.END); // 收缩
</wbr></span><wbr><wbr><wbr><wbr><wbr>//tv.setSingleLine(flag);
<wbr><wbr><wbr><wbr>}
<wbr><wbr><wbr>}
<wbr><wbr>});
<wbr>}
}</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>
其实，只是把样式清空而已。就能完全展开了。
有人可能要说，万一我想初始几行呢？放心，一样可以。上代码：
在xml文件中设置了如下属性：
android:lines="4"<wbr style="font-size:18px; font-family:Arial,Helvetica,sans-serif"><span style="font-size:18px; font-family:Arial,Helvetica,sans-serif"></span><wbr style="font-size:18px; font-family:Arial,Helvetica,sans-serif"><span style="font-size:18px; font-family:Arial,Helvetica,sans-serif"></span><wbr style="font-size:18px; font-family:Arial,Helvetica,sans-serif"><span style="font-size:18px; font-family:Arial,Helvetica,sans-serif"></span><wbr style="font-size:18px; font-family:Arial,Helvetica,sans-serif"><span style="font-size:18px; font-family:Arial,Helvetica,sans-serif"></span><wbr style="font-size:18px; font-family:Arial,Helvetica,sans-serif"><span style="font-size:18px; font-family:Arial,Helvetica,sans-serif; word-wrap:normal; word-break:normal"><wbr>//我初始化的4行</wbr></span><span style="font-size:18px; font-family:Arial,Helvetica,sans-serif"></span><span style="font-family:Arial,Helvetica,sans-serif; font-size:18px"></span></wbr></wbr></wbr></wbr></wbr>
Activity那边代码一样，只改一点
<wbr>if(flag){
<wbr><wbr><wbr><wbr><wbr><wbr><wbr>flag = false;
<span style="word-wrap:normal; word-break:normal"><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>tv.setEllipsize(null); // 展开
</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></span><span style="word-wrap:normal; word-break:normal"><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>tv.setSingleLine(flag);</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></span>
<wbr><wbr><wbr><wbr><wbr><wbr><wbr>}else{
<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>flag = true;
<span style="word-wrap:normal; word-break:normal"><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>tv.setEllipsize(TextUtils.TruncateAt.END); // 收缩
</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></span><wbr><wbr><wbr>}

<wbr>设置<span style="word-wrap:normal; word-break:normal">setSingleLine的目的是为了取消</span><span style="word-wrap:normal; word-break:normal">lines==“4”这个固定值。</span></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>