textview文字超長顯示展開和收起

 

判斷文字是否超長的方法

public static void showOrHideContent(TextView content,TextView btn,int maxLines,String btntext){
        Layout layout = content.getLayout();
        if (layout != null) {
            int lineCount = layout.getLineCount();
            if (lineCount > maxLines) {
                btn.setText(btntext);
                btn.setVisibility(View.VISIBLE);
            } else {
                int ellipsisCount = layout.getEllipsisCount(lineCount - 1);//小米note2下返回0
                if (ellipsisCount > 0) {
                    btn.setVisibility(View.VISIBLE);
                } else {
                    btn.setVisibility(View.GONE);
                }
            }
        } else {
            ViewTreeObserver observer = content.getViewTreeObserver();
            if (observer.isAlive()) {
                observer.addOnPreDrawListener(
                        new ViewTreeObserver.OnPreDrawListener() {
                            @Override
                            public boolean onPreDraw() {
                                Layout layout = content.getLayout();
                                if (layout != null) {
                                    int lineCount = layout.getLineCount();
                                    if (lineCount > maxLines) {//小米note2的兼容處理
                                        btn.setVisibility(View.VISIBLE);
                                    } else {
                                        int ellipsisCount = layout.getEllipsisCount(lineCount - 1);//小米note2下返回0
                                        if (ellipsisCount > 0) {
                                            btn.setVisibility(View.VISIBLE);
                                        } else {
                                            btn.setVisibility(View.GONE);
                                        }
                                    }
                                }
                                try {
                                    (content.getViewTreeObserver()).removeOnPreDrawListener(this);
                                } catch (Exception e) {
                                    e.printStackTrace();
                                }
                                return true;
                            }
                        }
                );
            }
        }
    }

調用方式：

content爲現實內容的textview，btn爲展開或者收起的按鈕，5爲textview最大顯示行數

StringUtils.showOrHideContent(content,btn,5,"查看全文");

btn的監聽事件：

btn.setOnClickListener(v -> {
            if(!isAll){
                content.setMaxHeight(getResources().getDisplayMetrics().heightPixels);
                btn.setText("收起");
                isAll = true;
            }else{
                content.setMaxLines(5);
                btn.setText("查看所有");
                isAll = false;
            }
        });

xml文件：

<TextView
            android:id="@+id/content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/name"
            android:layout_below="@+id/name"
            android:layout_marginRight="@dimen/app_margin"
            android:layout_marginTop="13sp"
            android:ellipsize="end"
            android:maxLines="5"
            android:text="贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少贍養費的給附表轉是多少"
            android:textColor="@color/black"
            android:textSize="15sp" />