Android显示全文折叠控件使用方法详解

一般列表里文字太多的一个折叠效果的空间，效果图如下。

当文字超过设定的行数后就折叠，小于设定行数不显示展开按钮。下面上代码。

先看布局文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:background="@color/color_white" >
 <TextView
 android:id="@+id/desc_tv"
 style="@style/font2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:gravity="center_vertical" />
 <TextView
 android:id="@+id/desc_op_tv"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_below="@+id/desc_tv"
 android:gravity="center_vertical"
 android:singleLine="true"
 android:text="@string/quan_wen"
 android:textColor="#5f897b"
 android:textSize="16sp"
 android:visibility="gone" />
</RelativeLayout>

很简单，上面的TextView显示主要的文本内容，下面的就是折叠的时候点击的。

下面是自定义。

package xxx;
import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.TextView.BufferType;
import xxx.R;
/**
 * 查看全文控件
 */
public class CollapsibleTextView extends LinearLayout implements View.OnClickListener {
 private static final int COLLAPSIBLE_STATE_NONE = 0;// 不显示
 private static final int COLLAPSIBLE_STATE_SHRINKUP = 1;// 显示收起
 private static final int COLLAPSIBLE_STATE_SPREAD = 2;// 显示全文
 private int mState = COLLAPSIBLE_STATE_SPREAD;
 private static final String COLLAPSIBLE_STATE_SHRINKUP_TEXT = "收起";
 private static final String COLLAPSIBLE_STATE_SPREAD_TEXT = "全文";
 private TextView mText;
 /**
 * @return Returns the mText.
 */
 public TextView getmText() {
 return mText;
 }
 public int getmState() {
 return mState;
 }
 public void setmState(int mState) {
 this.mState = mState;
 }
 private TextView mTextTip;
 private changeState changeStateCallBack;
 private boolean isNeedLayout;
 private int maxLineCount = 8;
 private final Handler handler = new Handler() {
 @Override
 public void dispatchMessage(Message msg) {
  if (mText.getLineCount() <= maxLineCount) {
  // 行数不足不做处理
  mState = COLLAPSIBLE_STATE_NONE;
  mText.setMaxLines(Integer.MAX_VALUE);
  mTextTip.setVisibility(View.GONE);
  }
  else {
  switch (mState) {
  case COLLAPSIBLE_STATE_SPREAD:
   // 全文状态
   mText.setMaxLines(maxLineCount);
   mTextTip.setVisibility(View.VISIBLE);
   mTextTip.setText(COLLAPSIBLE_STATE_SPREAD_TEXT);
   break;
  case COLLAPSIBLE_STATE_SHRINKUP:
   // 收起状态
   mText.setMaxLines(Integer.MAX_VALUE);
   mTextTip.setVisibility(View.VISIBLE);
   mTextTip.setText(COLLAPSIBLE_STATE_SHRINKUP_TEXT);
   break;
  default:
   // 除非发生不可知状态，一般不会执行到这个
   mState = COLLAPSIBLE_STATE_NONE;
   mText.setMaxLines(Integer.MAX_VALUE);
   mTextTip.setVisibility(View.GONE);
   break;
  }
  }
 }
 };
 public CollapsibleTextView(Context context) {
 this(context, null);
 initView();
 }
 public CollapsibleTextView(Context context, AttributeSet attrs) {
 super(context, attrs);
 initView();
 }
 @SuppressLint("NewApi")
 public CollapsibleTextView(Context context, AttributeSet attrs, int defStyle) {
 super(context, attrs, defStyle);
 initView();
 }
 private void initView() {
 View view = inflate(getContext(), R.layout.collapsible_textview, this);
 view.setPadding(0, -1, 0, 0);
 mText = (TextView) view.findViewById(R.id.desc_tv);
 mTextTip = (TextView) view.findViewById(R.id.desc_op_tv);
 mTextTip.setOnClickListener(this);
 }
 /**
 * 设置文本
 * 
 * @param charSequence
 * @param bufferType
 */
 public final void setText(CharSequence charSequence, BufferType bufferType) {
 isNeedLayout = true;
 mState = COLLAPSIBLE_STATE_SPREAD;
 mText.setText(charSequence, bufferType);
 }
 /**
 * 设置文本
 * 
 * @param charSequence
 */
 public final void setText(CharSequence charSequence) {
 isNeedLayout = true;
 mText.setText(charSequence);
 }
 @Override
 public void onClick(View v) {
 isNeedLayout = true;
 if (mState == COLLAPSIBLE_STATE_SPREAD) {
  // 如果是全文状态，就改成收起状态
  mState = COLLAPSIBLE_STATE_SHRINKUP;
  requestLayout();
 }
 else if (mState == COLLAPSIBLE_STATE_SHRINKUP) {
  // 如果是收起状态，就改成全文状态
  mState = COLLAPSIBLE_STATE_SPREAD;
  requestLayout();
 }
 if (null != changeStateCallBack) {
  changeStateCallBack.changeFlag(v);
 }
 }
 @Override
 protected void onLayout(boolean changed, int l, int t, int r, int b) {
 super.onLayout(changed, l, t, r, b);
 if (isNeedLayout) {
  isNeedLayout = false;
  handler.sendMessage(Message.obtain());
 }
 }
 public int getMaxLineCount() {
 return maxLineCount;
 }
 public void setMaxLineCount(int maxLineCount) {
 this.maxLineCount = maxLineCount;
 }
 public changeState getChangeStateCallBack() {
 return changeStateCallBack;
 }
 public void setChangeStateCallBack(changeState changeStateCallBack) {
 this.changeStateCallBack = changeStateCallBack;
 }
 public interface changeState {
 public void changeFlag(View v);
 }
}

点击展开后重新绘制根据状态值触发。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持呐喊教程。

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