1 page.title=Sending Content to Other Apps 2 parent.title=Sharing Content 3 parent.link=index.html 4 5 trainingnavtop=true 6 next.title=Receiving Content from Other Apps 7 next.link=receive.html 8 9 @jd:body 10 11 <div id="tb-wrapper"> 12 <div id="tb"> 13 14 <!-- table of contents --> 15 <h2>This lesson teaches you to</h2> 16 <ol> 17 <li><a href="#send-text-content">Send Text Content</a></li> 18 <li><a href="#send-binary-content">Send Binary Content</a></li> 19 <li><a href="#send-multiple-content">Send Multiple Pieces of Content</a></li> 20 </ol> 21 22 <!-- other docs (NOT javadocs) --> 23 <h2>You should also read</h2> 24 <ul> 25 <li><a href="{@docRoot}guide/components/intents-filters.html">Intents and 26 Intent Filters</a></li> 27 </ul> 28 29 </div> 30 </div> 31 32 <p>When you construct an intent, you must specify the action you want the intent to "trigger." 33 Android defines several actions, including {@link android.content.Intent#ACTION_SEND} which, as 34 you can probably guess, indicates that the intent is sending data from one activity to another, 35 even across process boundaries. To send data to another activity, all you need to do is specify 36 the data and its type, the system will identify compatible receiving activities and display them 37 to the user (if there are multiple options) or immediately start the activity (if there is only 38 one option). Similarly, you can advertise the data types that your activities support receiving 39 from other applications by specifying them in your manifest.</p> 40 41 <p>Sending and receiving data between applications with intents is most commonly used for social 42 sharing of content. Intents allow users to share information quickly and easily, using their 43 favorite applications.</p> 44 45 <p><strong>Note:</strong> The best way to add a share action item to an 46 {@link android.app.ActionBar} is to use {@link android.widget.ShareActionProvider}, which became 47 available in API level 14. {@link android.widget.ShareActionProvider} is discussed in the lesson 48 about <a href="shareaction.html">Adding an Easy Share Action</a>.</p> 49 50 51 <h2 id="send-text-content">Send Text Content</h2> 52 53 <div class="figure" style="width:220px"> 54 <img src="{@docRoot}images/training/sharing/share-text-screenshot.png" alt="" id="figure1" /> 55 <p class="img-caption"> 56 <strong>Figure 1.</strong> Screenshot of {@link android.content.Intent#ACTION_SEND} intent chooser 57 on a handset. 58 </p> 59 </div> 60 61 <p>The most straightforward and common use of the {@link android.content.Intent#ACTION_SEND} 62 action is sending text content from one activity to another. For example, the built-in Browser 63 app can share the URL of the currently-displayed page as text with any application. This is useful 64 for sharing an article or website with friends via email or social networking. Here is the code to 65 implement this type of sharing:</p> 66 67 <pre> 68 Intent sendIntent = new Intent(); 69 sendIntent.setAction(Intent.ACTION_SEND); 70 sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send."); 71 sendIntent.setType("text/plain"); 72 startActivity(sendIntent); 73 </pre> 74 75 <p>If there's an installed application with a filter that matches 76 {@link android.content.Intent#ACTION_SEND} and MIME type text/plain, the Android system will run 77 it; if more than one application matches, the system displays a disambiguation dialog (a "chooser") 78 that allows the user to choose an app. If you call 79 {@link android.content.Intent#createChooser(android.content.Intent, CharSequence) 80 Intent.createChooser()} 81 for the intent, Android will <strong>always</strong> display the chooser. This has some 82 advantages:</p> 83 84 <ul> 85 <li>Even if the user has previously selected a default action for this intent, the chooser will 86 still be displayed.</li> 87 <li>If no applications match, Android displays a system message.</li> 88 <li>You can specify a title for the chooser dialog.</li> 89 </ul> 90 91 <p>Here's the updated code:</p> 92 93 <pre> 94 Intent sendIntent = new Intent(); 95 sendIntent.setAction(Intent.ACTION_SEND); 96 sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send."); 97 sendIntent.setType("text/plain"); 98 startActivity(<strong>Intent.createChooser(sendIntent, getResources().getText(R.string.send_to))</strong>); 99 </pre> 100 101 <p>The resulting dialog is shown in figure 1.</p> 102 103 <p>Optionally, you can set some standard extras for the intent: 104 {@link android.content.Intent#EXTRA_EMAIL}, {@link android.content.Intent#EXTRA_CC}, 105 {@link android.content.Intent#EXTRA_BCC}, {@link android.content.Intent#EXTRA_SUBJECT}. However, 106 if the receiving application is not designed to use them, nothing will happen. You can use 107 custom extras as well, but there's no effect unless the receiving application understands them. 108 Typically, you'd use custom extras defined by the receiving application itself.</p> 109 110 <p class="note"><strong>Note:</strong> Some e-mail applications, such as Gmail, expect a 111 {@link java.lang.String String[]} for extras like {@link android.content.Intent#EXTRA_EMAIL} and 112 {@link android.content.Intent#EXTRA_CC}, use 113 {@link android.content.Intent#putExtra(String,String[]) putExtra(String, String[])} to add these 114 to your intent.</p> 115 116 117 <h2 id="send-binary-content">Send Binary Content</h2> 118 119 <p>Binary data is shared using the {@link android.content.Intent#ACTION_SEND} action combined with 120 setting the appropriate MIME type and placing the URI to the data in an extra named {@link 121 android.content.Intent#EXTRA_STREAM}. This is commonly used to share an image but can be used to 122 share any type of binary content:</p> 123 124 <pre> 125 Intent shareIntent = new Intent(); 126 shareIntent.setAction(Intent.ACTION_SEND); 127 shareIntent.putExtra(Intent.EXTRA_STREAM, uriToImage); 128 shareIntent.setType("image/jpeg"); 129 startActivity(Intent.createChooser(shareIntent, getResources().getText(R.string.send_to))); 130 </pre> 131 132 <p>Note the following:</p> 133 <ul> 134 <li>You can use a MIME type of {@code "*/*"}, but this will only match activities that are able to 135 handle generic data streams.</li> 136 <li>The receiving application needs permission to access the data the {@link android.net.Uri} 137 points to. There are a number of ways to handle this: 138 <ul> 139 <li>Write the data to a file on external/shared storage (such as the SD card), which all apps 140 can read. Use {@link android.net.Uri#fromFile(java.io.File) Uri.fromFile()} to create the 141 {@link android.net.Uri} that can be passed to the share intent. However, keep in mind that not 142 all applications process a {@code file://} style {@link android.net.Uri}.</li> 143 <li>Write the data to a file in your own application directory using {@link 144 android.content.Context#openFileOutput(java.lang.String, int) openFileOutput()} with mode {@link 145 android.content.Context#MODE_WORLD_READABLE} after which {@link 146 android.content.Context#getFileStreamPath(java.lang.String) getFileStreamPath()} can be used to 147 return a {@link java.io.File}. As with the previous option, {@link 148 android.net.Uri#fromFile(java.io.File) Uri.fromFile()} will create a {@code file://} style {@link 149 android.net.Uri} for your share intent.</li> 150 <li>Media files like images, videos and audio can be scanned and added to the system {@link 151 android.provider.MediaStore} using {@link 152 android.media.MediaScannerConnection#scanFile(android.content.Context, java.lang.String[], 153 java.lang.String[], android.media.MediaScannerConnection.OnScanCompletedListener) scanFile()}. The 154 {@link 155 android.media.MediaScannerConnection.OnScanCompletedListener#onScanCompleted(java.lang.String, 156 android.net.Uri) onScanCompleted()} callback returns a {@code content://} style {@link 157 android.net.Uri} suitable for including in your share intent.</li> 158 <li>Images can be inserted into the system {@link android.provider.MediaStore} using {@link 159 android.provider.MediaStore.Images.Media#insertImage(android.content.ContentResolver, 160 android.graphics.Bitmap, java.lang.String, java.lang.String) insertImage()} which will return a 161 {@code content://} style {@link android.net.Uri} suitable for including in a share intent.</li> 162 <li>Store the data in your own {@link android.content.ContentProvider}, make sure that other 163 apps have the correct permission to access your provider (or use <a 164 href="{@docRoot}guide/topics/security/security.html#uri">per-URI permissions</a>).</li> 165 </ul> 166 </li> 167 </ul> 168 169 170 <h2 id="send-multiple-content">Send Multiple Pieces of Content</h2> 171 172 <p>To share multiple pieces of content, use the {@link android.content.Intent#ACTION_SEND_MULTIPLE} 173 action together with a list of URIs pointing to the content. The MIME type varies according to the 174 mix of content you're sharing. For example, if you share 3 JPEG images, the type is still {@code 175 "image/jpeg"}. For a mixture of image types, it should be {@code "image/*"} to match an activity 176 that handles any type of image. You should only use {@code "*/*"} if you're sharing out a wide 177 variety of types. As previously stated, it's up to the receiving application to parse and process 178 your data. Here's an example:</p> 179 180 <pre> 181 ArrayList<Uri> imageUris = new ArrayList<Uri>(); 182 imageUris.add(imageUri1); // Add your image URIs here 183 imageUris.add(imageUri2); 184 185 Intent shareIntent = new Intent(); 186 shareIntent.setAction(Intent.ACTION_SEND_MULTIPLE); 187 shareIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, imageUris); 188 shareIntent.setType("image/*"); 189 startActivity(Intent.createChooser(shareIntent, "Share images to..")); 190 </pre> 191 192 <p>As before, make sure the provided {@link android.net.Uri URIs} point to data that a receiving 193 application can access.</p> 194 195
