在将 textview渲染到布局之前,找不到任何计算 textview 高度的好的解决方案。请提供任何帮助
6 回答
2个解决方案
最初使用解决方案 1,后来找到解决方案 2。两者都有效,这确实是您喜欢的。
重要的是确保所有尺寸都正确,因为在 sp 或 px 中混合字体大小会根据您测试的屏幕产生很大差异。
https://github.com/hanscappelle/SO-3654321提供了一个非常基本的示例项目
使用 TextView 和 MeasureSpec 的解决方案 1
原始问题的主要问题是下面方法中的 TextView 应该配置为我们的 TextView 应该呈现到布局。我认为这个解决方案对于许多面临这个问题的人来说很有价值。
public static int getHeight(Context context, CharSequence text, int textSize, int deviceWidth, Typeface typeface,int padding) {
TextView textView = new TextView(context);
textView.setPadding(padding,0,padding,padding);
textView.setTypeface(typeface);
textView.setText(text, TextView.BufferType.SPANNABLE);
textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, textSize);
int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(deviceWidth, View.MeasureSpec.AT_MOST);
int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
textView.measure(widthMeasureSpec, heightMeasureSpec);
return textView.getMeasuredHeight();
}
以及如何使用它的示例:
// retrieve deviceWidth
int deviceWidth;
WindowManager wm = (WindowManager) textView.getContext().getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
if(android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2){
Point size = new Point();
display.getSize(size);
deviceWidth = size.x;
} else {
deviceWidth = display.getWidth();
}
// the text to check for
String exampleTextToMeasure = "some example text that will be long enough to make this example split over multiple lines so we can't easily predict the final height";
// some dimensions from dimes resources to take into account
int textSize = getContext().getResources().getDimensionPixelSize(R.dimen.text_size);
int padding = getContext().getResources().getDimensionPixelSize(R.dimen.text_padding);
// final calculation of textView height
int measuredTextHeight = getHeight(getContext(), exampleTextToMeasure, textSize, deviceWidth, TypeFace.DEFAULT, padding);
使用 TextPaint 和 StaticLayout 的解决方案 2
此方法依赖于 TextPaint 和 StaticLayout,这也为我迄今为止测试过的所有 API 级别提供了可靠的结果。注意尺寸单位;一切都应该以像素为单位!
来源:测量要在 Canvas 上绘制的文本高度(Android)
public static int method1UsingTextPaintAndStaticLayout(
final CharSequence text,
final int textSize, // in pixels
final int deviceWidth, // in pixels
final int padding // in pixels
) {
TextPaint myTextPaint = new TextPaint();
myTextPaint.setAntiAlias(true);
// this is how you would convert sp to pixels based on screen density
//myTextPaint.setTextSize(16 * context.getResources().getDisplayMetrics().density);
myTextPaint.setTextSize(textSize);
Layout.Alignment alignment = Layout.Alignment.ALIGN_NORMAL;
float spacingMultiplier = 1;
float spacingAddition = padding; // optionally apply padding here
boolean includePadding = padding != 0;
StaticLayout myStaticLayout = new StaticLayout(text, myTextPaint, deviceWidth, alignment, spacingMultiplier, spacingAddition, includePadding);
return myStaticLayout.getHeight();
}
从 support_ms 的回答中,有一个更简单的方法,它只接受一个 TextView 作为参数。
/**
* Get the TextView height before the TextView will render
* @param textView the TextView to measure
* @return the height of the textView
*/
public static int getTextViewHeight(TextView textView) {
WindowManager wm =
(WindowManager) textView.getContext().getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
int deviceWidth;
if(android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2){
Point size = new Point();
display.getSize(size);
deviceWidth = size.x;
} else {
deviceWidth = display.getWidth();
}
int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(deviceWidth, View.MeasureSpec.AT_MOST);
int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
textView.measure(widthMeasureSpec, heightMeasureSpec);
return textView.getMeasuredHeight();
}
@support_ms 的好答案,但我不确定创建一个新的 TextView 并计算所有这些输入参数的意义,因为你可以先格式化你的 TextView,然后只用一个参数调用静态方法,它TextView
本身!
另外我不确定为什么一个参数被标记deviceWidth
我只使用Textview
它本身的宽度。我的是match_parent
,我想任何一个TextView
都wrap_content
可能根本不起作用。但这就是你得到的。
public static int getHeight(TextView t) {
int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(screenWidth(t.getContext()), View.MeasureSpec.AT_MOST);
int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
t.measure(widthMeasureSpec, heightMeasureSpec);
return t.getMeasuredHeight();
}
public static int screenWidth(Context context)
{
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
return display.getWidth();
}
这是我的简单解决方案,它在绘制之前获得尺寸
渲染前获取TextView的行
这是我基于上述想法的代码。它对我有用。
private int widthMeasureSpec;
private int heightMeasureSpec;
private int heightOfEachLine;
private int paddingFirstLine;
private void calculateHeightOfEachLine() {
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int deviceWidth = size.x;
widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(deviceWidth, View.MeasureSpec.AT_MOST);
heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
//1 line = 76; 2 lines = 76 + 66; 3 lines = 76 + 66 + 66
//=> height of first line = 76 pixel; height of second line = third line =... n line = 66 pixel
int heightOfFirstLine = getHeightOfTextView("A");
int heightOfSecondLine = getHeightOfTextView("A\nA") - heightOfFirstLine;
paddingFirstLine = heightOfFirstLine - heightOfSecondLine;
heightOfEachLine = heightOfSecondLine;
}
private int getHeightOfTextView(String text) {
// Getting height of text view before rendering to layout
TextView textView = new TextView(context);
textView.setPadding(10, 0, 10, 0);
//textView.setTypeface(typeface);
textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.tv_size_14sp));
textView.setText(text, TextView.BufferType.SPANNABLE);
textView.measure(widthMeasureSpec, heightMeasureSpec);
return textView.getMeasuredHeight();
}
private int getLineCountOfTextViewBeforeRendering(String text) {
return (getHeightOfTextView(text) - paddingFirstLine) / heightOfEachLine;
}
注意:此代码也必须设置为屏幕上的真实文本视图
textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.tv_size_14sp));
Kotlin 扩展
fun TextView.calculateHeight(text: CharSequence = getText()): Int {
val alignment = when(gravity) {
Gravity.CENTER -> Layout.Alignment.ALIGN_CENTER
Gravity.RIGHT -> Layout.Alignment.ALIGN_OPPOSITE
else -> Layout.Alignment.ALIGN_NORMAL
}
return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
StaticLayout.Builder.obtain(text, 0, text.length, TextPaint(paint), width)
.setLineSpacing(lineSpacingExtra, lineSpacingMultiplier)
.setAlignment(alignment)
.setIncludePad(true).build()
} else {
@Suppress("DEPRECATION")
StaticLayout(
text, TextPaint(paint), width, alignment,
lineSpacingMultiplier, lineSpacingExtra, true
)
}.height
}