對於設置TextView的字體默認大小對於UI界面的好看程度是很重要的，小屏幕設置的文字過大或者大屏幕設置的文字過小都造成UI的不美觀

現在就讓我們學習自適應大小的TextView控件，即當文字長度變化時，文字的大小會相應的變化，保證顯示在一行當中

實現依靠於第三方類庫

第三方類來源：

https://github.com/grantland/android-autofittextview

和正常的使用TextView一樣，只需要將要自適應的TextView標簽設置為<me.grantland.widget.AutofitTextView/>

註意：一定要設置為單行，否定無法顯示效果

android:singleLine="true"

 1 <me.grantland.widget.AutofitTextView
 2             android:id="@+id/output_autofit"
 3             android:layout_width="match_parent"
 4             android:layout_height="wrap_content"
 5             android:text="@string/example
 
"
 6             android:textSize="50sp"
 7             android:gravity="center"
 8             android:singleLine="true"
 9             autofit:minTextSize="8sp"
10             />

布局文件：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android
 
"
 3             xmlns:autofit="http://schemas.android.com/apk/res-auto"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent">
 6     <LinearLayout
 7         android:layout_width="match_parent"
 8         android:layout_height="wrap_content"
 9         android:orientation="vertical"
10         >
11         <EditText
12             android:id="@+id/input"
13             android:layout_width="match_parent"
14             android:layout_height="wrap_content"
15             android:singleLine="true"
16             android:hint="@string/input_hint"
17             android:text="@string/example"/>
18         <TextView
19             android:layout_width="match_parent"
20             android:layout_height="wrap_content"
21             android:text="@string/label_normal"
22             />
23         <TextView
24             android:id="@+id/output"
25             android:layout_width="match_parent"
26             android:layout_height="wrap_content"
27             android:text="@string/example"
28             android:textSize="50sp"
29             android:gravity="center"
30             />
31         <TextView
32             android:layout_width="match_parent"
33             android:layout_height="wrap_content"
34             android:text="@string/label_autofit"
35             />
36         <me.grantland.widget.AutofitTextView
37             android:id="@+id/output_autofit"
38             android:layout_width="match_parent"
39             android:layout_height="wrap_content"
40             android:text="@string/example"
41             android:textSize="50sp"
42             android:gravity="center"
43             android:singleLine="true"
44             autofit:minTextSize="8sp"
45             />
46     </LinearLayout>
47 </ScrollView>

string.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <resources>
 3 
 4     <string name="app_name">Texttest</string>
 5     <string name="action_settings">Settings</string>
 6     <string name="hello_world">Hello world!</string>
 7 
 8     <string name="input_hint">text</string>
 9     <string name="label_normal">Normal:</string>
10     <string name="label_autofit">Autofit:</string>
11 
12     <string name="example">This is an example</string>
13 
14 </resources>

activity

 1 package com.example.texttest;
 2 
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 import android.text.Editable;
 6 import android.text.TextWatcher;
 7 import android.view.Menu;
 8 import android.widget.EditText;
 9 import android.widget.TextView;
10 
11 public class MainActivity extends Activity {
12 
13     private TextView mOutput;
14     private TextView mAutofitOutput;
15     @Override
16     protected void onCreate(Bundle savedInstanceState) {
17         super.onCreate(savedInstanceState);
18         setContentView(R.layout.activity_main);
19         mOutput = (TextView)findViewById(R.id.output);
20         mAutofitOutput = (TextView)findViewById(R.id.output_autofit);
21 
22         ((EditText)findViewById(R.id.input)).addTextChangedListener(new TextWatcher() {
23             @Override
24             public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
25                 // do nothing
26             }
27 
28             @Override
29             public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
30                 mOutput.setText(charSequence);
31                 mAutofitOutput.setText(charSequence);
32             }
33 
34             @Override
35             public void afterTextChanged(Editable editable) {
36                 // do nothing
37             }
38         });
39     }
40     
41 
42 
43     @Override
44     public boolean onCreateOptionsMenu(Menu menu) {
45         // Inflate the menu; this adds items to the action bar if it is present.
46         getMenuInflater().inflate(R.menu.main, menu);
47         return true;
48     }
49     
50 }

效果：

Android項目實戰（五）：TextView自適應大小