Android 显示全文折叠控件

绝地灬酷狼 2022-07-15 05:08 205阅读 0赞

转载请注明来源！

**一般列表里文字太多的一个折叠效果的空间，效果图如下**。

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![这里写图片描述][20161103104940144]

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**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。**

转载请注明来源！

[20161103104940144]: /images/20220715/115cda59a0af408089bb32674202cd54.png