textview文字超长显示展开和收起

 

判断文字是否超长的方法

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的兼容处理
                                        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;
                            }
                        }
                );
            }
        }
    }

调用方式：

content为现实内容的textview，btn为展开或者收起的按钮，5为textview最大显示行数

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

btn的监听事件：

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="赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少赡养费的给附表转是多少"
            android:textColor="@color/black"
            android:textSize="15sp" />